vendor/libc++/libc++-trunk-r290819

30 files changed, 8957 insertions, 119 deletions

diff --git a/test/std/strings/basic.string/string.modifiers/string_append/T_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/T_size_size.pass.cpp
new file mode 100644
index 000000000000..fcd18b7f05be
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_append/T_size_size.pass.cpp
@@ -0,0 +1,200 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& append(const T& t, size_type pos, size_type n=npos); // C++17
+
+#include <string>
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, SV sv, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.append(sv, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.append(sv, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+void
+test_npos(S s, SV sv, typename S::size_type pos, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.append(sv, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.append(sv, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S("12345"));
+    test(S("12345"), SV("12345"), 2, 2, S("1234534"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S("12345"));
+    test(S("12345"), SV("12345"), 2, 2, S("1234534"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("123451234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("12345678901234567890234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("123456789012345678906789012345"));
+    }
+#endif
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test_npos(S(), SV(), 0, S());
+    test_npos(S(), SV(), 1, S());
+    test_npos(S(), SV("12345"), 0, S("12345"));
+    test_npos(S(), SV("12345"), 1, S("2345"));
+    test_npos(S(), SV("12345"), 3, S("45"));
+    test_npos(S(), SV("12345"), 5, S(""));
+    test_npos(S(), SV("12345"), 6, S("not happening"));
+    }
+
+    {
+    std::string s;
+    std::string_view sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s.append("CDEF", 0);    // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.append("QRST", 0, std::string::npos); // calls append(string("QRST"), pos, npos)
+    assert(s == "QRST");
+    s.clear();
+
+    s.append(sv, 0);  // calls append(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.append(sv, 0, std::string::npos);   // calls append(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.append(arr, 0);     // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.append(arr, 0, std::string::npos);    // calls append(string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    s.clear();
+
+    s.append(arr, 0);     // calls append(const char *, len)
+    assert(s == "");
+    s.clear();
+    }
+
+    {
+    std::string s = "ABCD";
+    std::string_view sv = s;
+    s.append(sv);
+    assert(s == "ABCDABCD");
+
+    sv = s;
+    s.append(sv, 0, std::string::npos);
+    assert(s == "ABCDABCDABCDABCD");
+
+    sv = s;
+    s.append(sv, sv.size());
+    assert(s == "ABCDABCDABCDABCD");
+    }
+
+    {
+    std::string s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    std::string_view sv = s;
+    s.append(sv);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ");
+
+    sv = s;
+    s.append(sv, 0, std::string::npos);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ");
+    }
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_append/iterator.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/iterator.pass.cpp
index 55fc63d06214..dac8860f9a64 100644
--- a/test/std/strings/basic.string/string.modifiers/string_append/iterator.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_append/iterator.pass.cpp
@@ -178,4 +178,30 @@ int main()
     test_exceptions(S(), TIter(s, s+10, 6, TIter::TAComparison), TIter());
 	}
 #endif
+
+	{ // test appending to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.append(s_short.begin(), s_short.end());
+	assert(s_short == "123/123/");
+	s_short.append(s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/");
+	s_short.append(s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.append(s_long.begin(), s_long.end());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
+
+	{ // test appending a different type
+    typedef std::string S;
+	const uint8_t p[] = "ABCD";
+
+	S s;
+	s.append(p, p + 4);
+	assert(s == "ABCD");
+	}
+
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_append/pointer.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/pointer.pass.cpp
index 7c45068a53e1..eb552ca83928 100644
--- a/test/std/strings/basic.string/string.modifiers/string_append/pointer.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_append/pointer.pass.cpp
@@ -61,4 +61,20 @@ int main()
          S("1234567890123456789012345678901234567890"));
     }
 #endif
+
+	{ // test appending to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.append(s_short.c_str());
+	assert(s_short == "123/123/");
+	s_short.append(s_short.c_str());
+	assert(s_short == "123/123/123/123/");
+	s_short.append(s_short.c_str());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.append(s_long.c_str());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_append/pointer_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/pointer_size.pass.cpp
index 6c594ebac3be..fc80d7cccce6 100644
--- a/test/std/strings/basic.string/string.modifiers/string_append/pointer_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_append/pointer_size.pass.cpp
@@ -70,4 +70,20 @@ int main()
          S("1234567890123456789012345678901234567890"));
     }
 #endif
+
+	{ // test appending to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.append(s_short.data(), s_short.size());
+	assert(s_short == "123/123/");
+	s_short.append(s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/");
+	s_short.append(s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.append(s_long.data(), s_long.size());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_append/string_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/string_size_size.pass.cpp
index 9e8158c3e43e..588c15ab8d6a 100644
--- a/test/std/strings/basic.string/string.modifiers/string_append/string_size_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_append/string_size_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -25,34 +24,52 @@ template <class S>
 void
 test(S s, S str, typename S::size_type pos, typename S::size_type n, S expected)
 {
-    try
+    if (pos <= str.size())
     {
         s.append(str, pos, n);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > str.size());
+        try
+        {
+            s.append(str, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
     }
+#endif
 }
 
 template <class S>
 void
 test_npos(S s, S str, typename S::size_type pos, S expected)
 {
-    try
+    if (pos <= str.size())
     {
         s.append(str, pos);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > str.size());
+        try
+        {
+            s.append(str, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
     }
+#endif
 }
 
 int main()
diff --git a/test/std/strings/basic.string/string.modifiers/string_append/string_view.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_append/string_view.pass.cpp
new file mode 100644
index 000000000000..2d85b15fa373
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_append/string_view.pass.cpp
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   append(basic_string_view<charT,traits> sv);
+
+#include <string>
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, SV sv, S expected)
+{
+    s.append(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S("12345"));
+    test(S("12345"), SV("12345"), S("1234512345"));
+    test(S("12345"), SV("1234567890"), S("123451234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), SV(), S("1234567890"));
+    test(S("1234567890"), SV("12345"), S("123456789012345"));
+    test(S("1234567890"), SV("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S("12345"));
+    test(S("12345"), SV("12345"), S("1234512345"));
+    test(S("12345"), SV("1234567890"), S("123451234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("1234512345678901234567890"));
+
+    test(S("1234567890"), SV(), S("1234567890"));
+    test(S("1234567890"), SV("12345"), S("123456789012345"));
+    test(S("1234567890"), SV("1234567890"), S("12345678901234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("123456789012345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S("12345678901234567890"));
+    test(S("12345678901234567890"), SV("12345"), S("1234567890123456789012345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("123456789012345678901234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("1234567890123456789012345678901234567890"));
+    }
+#endif
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/T_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/T_size_size.pass.cpp
new file mode 100644
index 000000000000..bf51d816e86e
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/T_size_size.pass.cpp
@@ -0,0 +1,195 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& assign(const T& t, size_type pos, size_type n=npos); // C++17
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, SV sv, typename S::size_type pos, typename S::size_type n, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.assign(sv, pos, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.assign(sv, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+void
+test_npos(S s, SV sv, typename S::size_type pos, S expected)
+{
+    if (pos <= sv.size())
+    {
+        s.assign(sv, pos);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.assign(sv, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > sv.size());
+        }
+    }
+#endif
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S());
+    test(S("12345"), SV("12345"), 2, 2, S("34"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S());
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("6789012345"));
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), 0, 0, S());
+    test(S(), SV(), 1, 0, S());
+    test(S(), SV("12345"), 0, 3, S("123"));
+    test(S(), SV("12345"), 1, 4, S("2345"));
+    test(S(), SV("12345"), 3, 15, S("45"));
+    test(S(), SV("12345"), 5, 15, S(""));
+    test(S(), SV("12345"), 6, 15, S("not happening"));
+    test(S(), SV("12345678901234567890"), 0, 0, S());
+    test(S(), SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(), SV("12345678901234567890"), 2, 3, S("345"));
+    test(S(), SV("12345678901234567890"), 12, 13, S("34567890"));
+    test(S(), SV("12345678901234567890"), 21, 13, S("not happening"));
+
+    test(S("12345"), SV(), 0, 0, S());
+    test(S("12345"), SV("12345"), 2, 2, S("34"));
+    test(S("12345"), SV("1234567890"), 0, 100, S("1234567890"));
+
+    test(S("12345678901234567890"), SV(), 0, 0, S());
+    test(S("12345678901234567890"), SV("12345"), 1, 3, S("234"));
+    test(S("12345678901234567890"), SV("12345678901234567890"), 5, 10,
+         S("6789012345"));
+    }
+#endif
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test_npos(S(), SV(), 0, S());
+    test_npos(S(), SV(), 1, S());
+    test_npos(S(), SV("12345"), 0, S("12345"));
+    test_npos(S(), SV("12345"), 1, S("2345"));
+    test_npos(S(), SV("12345"), 3, S("45"));
+    test_npos(S(), SV("12345"), 5, S(""));
+    test_npos(S(), SV("12345"), 6, S("not happening"));
+    }
+
+    {
+    std::string s = "ABCD";
+    std::string_view sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s.assign("CDEF", 0);    // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.assign("QRST", 0, std::string::npos); // calls assign(string("QRST", pos, len)
+    assert(s == "QRST");
+    s.clear();
+
+    s.assign(sv, 0);  // calls assign(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.assign(sv, 0, std::string::npos);   // calls assign(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.assign(arr, 0);     // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.assign(arr, 0, std::string::npos);    // calls assign(string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    s.clear();
+
+    s.assign(arr, 0);     // calls assign(const char *, len)
+    assert(s == "");
+    s.clear();
+    }
+
+    {
+    std::string s = "ABCD";
+    std::string_view sv = s;
+    s.assign(sv);
+    assert(s == "ABCD");
+
+    sv = s;
+    s.assign(sv, 0, std::string::npos);
+    assert(s == "ABCD");
+    }
+
+    {
+    std::string s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    std::string_view sv = s;
+    s.assign(sv);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+
+    sv = s;
+    s.assign(sv, 0, std::string::npos);
+    assert(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+    }
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp
index e6a57519f34b..e5312e6db6ce 100644
--- a/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp
@@ -179,4 +179,30 @@ int main()
     test_exceptions(S(), TIter(s, s+10, 6, TIter::TAComparison), TIter());
 	}
 #endif
+
+	{ // test assigning to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.assign(s_short.begin(), s_short.end());
+	assert(s_short == "123/");
+	s_short.assign(s_short.begin() + 2, s_short.end());
+	assert(s_short == "3/");
+
+	s_long.assign(s_long.begin(), s_long.end());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/");
+
+	s_long.assign(s_long.begin() + 30, s_long.end());
+	assert(s_long == "nsectetur/");
+	}
+
+	{ // test assigning a different type
+    typedef std::string S;
+	const uint8_t p[] = "ABCD";
+
+	S s;
+	s.assign(p, p + 4);
+	assert(s == "ABCD");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/pointer.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/pointer.pass.cpp
index 386dee6d5808..b0876b388d83 100644
--- a/test/std/strings/basic.string/string.modifiers/string_assign/pointer.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/pointer.pass.cpp
@@ -61,4 +61,18 @@ int main()
          S("12345678901234567890"));
     }
 #endif
+
+	{ // test assignment to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.assign(s_short.c_str());
+	assert(s_short == "123/");
+	s_short.assign(s_short.c_str() + 2);
+	assert(s_short == "3/");
+
+	s_long.assign(s_long.c_str() + 30);
+	assert(s_long == "nsectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/pointer_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/pointer_size.pass.cpp
index 0eeb9266f40f..97a9990f5180 100644
--- a/test/std/strings/basic.string/string.modifiers/string_assign/pointer_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/pointer_size.pass.cpp
@@ -70,4 +70,20 @@ int main()
          S("12345678901234567890"));
     }
 #endif
+	{ // test assign to self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.assign(s_short.data(), s_short.size());
+	assert(s_short == "123/");
+	s_short.assign(s_short.data() + 2, s_short.size() - 2);
+	assert(s_short == "3/");
+
+	s_long.assign(s_long.data(), s_long.size());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/");
+
+	s_long.assign(s_long.data() + 2, 8 );
+	assert(s_long == "rem ipsu");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/string_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/string_size_size.pass.cpp
index d9d3cb422ae5..2ad37f311de5 100644
--- a/test/std/strings/basic.string/string.modifiers/string_assign/string_size_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/string_size_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -25,34 +24,52 @@ template <class S>
 void
 test(S s, S str, typename S::size_type pos, typename S::size_type n, S expected)
 {
-    try
+    if (pos <= str.size())
     {
         s.assign(str, pos, n);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > str.size());
+        try
+        {
+            s.assign(str, pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
     }
+#endif
 }
 
 template <class S>
 void
 test_npos(S s, S str, typename S::size_type pos, S expected)
 {
-    try
+    if (pos <= str.size())
     {
         s.assign(str, pos);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > str.size());
+        try
+        {
+            s.assign(str, pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
     }
+#endif
 }
 
 int main()
diff --git a/test/std/strings/basic.string/string.modifiers/string_assign/string_view.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_assign/string_view.pass.cpp
new file mode 100644
index 000000000000..e56b094a36e9
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_assign/string_view.pass.cpp
@@ -0,0 +1,105 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>&
+//   assign(basic_string_view<charT,traits> sv);
+
+#include <string>
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+#include "test_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, SV sv, S expected)
+{
+    s.assign(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == expected);
+}
+
+template <class S, class SV>
+void
+testAlloc(S s, SV sv, const typename S::allocator_type& a)
+{
+    s.assign(sv);
+    LIBCPP_ASSERT(s.__invariants());
+    assert(s == sv);
+    assert(s.get_allocator() == a);
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S());
+    test(S("12345"), SV("12345"), S("12345"));
+    test(S("12345"), SV("1234567890"), S("1234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), SV(), S());
+    test(S("1234567890"), SV("12345"), S("12345"));
+    test(S("1234567890"), SV("1234567890"), S("1234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S());
+    test(S("12345678901234567890"), SV("12345"), S("12345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), SV(), std::allocator<char>());
+    testAlloc(S(), SV("12345"), std::allocator<char>());
+    testAlloc(S(), SV("1234567890"), std::allocator<char>());
+    testAlloc(S(), SV("12345678901234567890"), std::allocator<char>());
+    }
+
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string     <char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char> > SV;
+    test(S(), SV(), S());
+    test(S(), SV("12345"), S("12345"));
+    test(S(), SV("1234567890"), S("1234567890"));
+    test(S(), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345"), SV(), S());
+    test(S("12345"), SV("12345"), S("12345"));
+    test(S("12345"), SV("1234567890"), S("1234567890"));
+    test(S("12345"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("1234567890"), SV(), S());
+    test(S("1234567890"), SV("12345"), S("12345"));
+    test(S("1234567890"), SV("1234567890"), S("1234567890"));
+    test(S("1234567890"), SV("12345678901234567890"), S("12345678901234567890"));
+
+    test(S("12345678901234567890"), SV(), S());
+    test(S("12345678901234567890"), SV("12345"), S("12345"));
+    test(S("12345678901234567890"), SV("1234567890"), S("1234567890"));
+    test(S("12345678901234567890"), SV("12345678901234567890"),
+         S("12345678901234567890"));
+
+    testAlloc(S(), SV(), min_allocator<char>());
+    testAlloc(S(), SV("12345"), min_allocator<char>());
+    testAlloc(S(), SV("1234567890"), min_allocator<char>());
+    testAlloc(S(), SV("12345678901234567890"), min_allocator<char>());
+    }
+#endif
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_copy/copy.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_copy/copy.pass.cpp
index b66877652837..664d2049be99 100644
--- a/test/std/strings/basic.string/string.modifiers/string_copy/copy.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_copy/copy.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // size_type copy(charT* s, size_type n, size_type pos = 0) const;
@@ -25,20 +24,30 @@ void
 test(S str, typename S::value_type* s, typename S::size_type n,
      typename S::size_type pos)
 {
-    try
+    const S& cs = str;
+    if (pos <= cs.size())
     {
-        const S& cs = str;
         typename S::size_type r = cs.copy(s, n, pos);
-        assert(pos <= cs.size());
         typename S::size_type rlen = std::min(n, cs.size() - pos);
         assert(r == rlen);
         for (r = 0; r < rlen; ++r)
             assert(S::traits_type::eq(cs[pos+r], s[r]));
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > str.size());
+        try
+        {
+            typename S::size_type r = cs.copy(s, n, pos);
+            ((void)r); // Prevent unused warning
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > str.size());
+        }
     }
+#endif
 }
 
 int main()
diff --git a/test/std/strings/basic.string/string.modifiers/string_erase/size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_erase/size_size.pass.cpp
index 5db97ec2cf5f..eb6be202a350 100644
--- a/test/std/strings/basic.string/string.modifiers/string_erase/size_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_erase/size_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -24,40 +23,58 @@ template <class S>
 void
 test(S s, typename S::size_type pos, typename S::size_type n, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.erase(pos, n);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.erase(pos, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
 void
 test(S s, typename S::size_type pos, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.erase(pos);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.erase(pos);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/iter_iter_iter.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/iter_iter_iter.pass.cpp
index bbae39419da4..e5ce8e51e1d6 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/iter_iter_iter.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/iter_iter_iter.pass.cpp
@@ -169,4 +169,29 @@ int main()
         assert(false);
     }
 #endif
+
+	{ // test inserting into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/");
+	s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/");
+	s_short.insert(s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.insert(s_long.begin(), s_long.begin(), s_long.end());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
+
+	{ // test assigning a different type
+    typedef std::string S;
+	const uint8_t p[] = "ABCD";
+
+	S s;
+	s.insert(s.begin(), p, p + 4);
+	assert(s == "ABCD");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_T_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_T_size_size.pass.cpp
new file mode 100644
index 000000000000..e9476f48f358
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_T_size_size.pass.cpp
@@ -0,0 +1,1842 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& assign(size_type pos1, const T& t, size_type pos2, size_type n=npos); // C++17
+//
+//  Mostly we're testing string_view here
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, typename S::size_type pos1, SV sv, typename S::size_type pos2,
+     typename S::size_type n, S expected)
+{
+    static_assert((!std::is_same<S, SV>::value), "");
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos1 <= old_size && pos2 <= sv.size())
+    {
+        s.insert(pos1, sv, pos2, n);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.insert(pos1, sv, pos2, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > sv.size());
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+void
+test_npos(S s, typename S::size_type pos1, SV sv, typename S::size_type pos2, S expected)
+{
+    static_assert((!std::is_same<S, SV>::value), "");
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos1 <= old_size && pos2 <= sv.size())
+    {
+        s.insert(pos1, sv, pos2);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.insert(pos1, sv, pos2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > sv.size());
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+
+template <class S, class SV>
+void test0()
+{
+    test(S(""), 0, SV(""), 0, 0, S(""));
+    test(S(""), 0, SV(""), 0, 1, S(""));
+    test(S(""), 0, SV(""), 1, 0, S("can't happen"));
+    test(S(""), 0, SV("12345"), 0, 0, S(""));
+    test(S(""), 0, SV("12345"), 0, 1, S("1"));
+    test(S(""), 0, SV("12345"), 0, 2, S("12"));
+    test(S(""), 0, SV("12345"), 0, 4, S("1234"));
+    test(S(""), 0, SV("12345"), 0, 5, S("12345"));
+    test(S(""), 0, SV("12345"), 0, 6, S("12345"));
+    test(S(""), 0, SV("12345"), 1, 0, S(""));
+    test(S(""), 0, SV("12345"), 1, 1, S("2"));
+    test(S(""), 0, SV("12345"), 1, 2, S("23"));
+    test(S(""), 0, SV("12345"), 1, 3, S("234"));
+    test(S(""), 0, SV("12345"), 1, 4, S("2345"));
+    test(S(""), 0, SV("12345"), 1, 5, S("2345"));
+    test(S(""), 0, SV("12345"), 2, 0, S(""));
+    test(S(""), 0, SV("12345"), 2, 1, S("3"));
+    test(S(""), 0, SV("12345"), 2, 2, S("34"));
+    test(S(""), 0, SV("12345"), 2, 3, S("345"));
+    test(S(""), 0, SV("12345"), 2, 4, S("345"));
+    test(S(""), 0, SV("12345"), 4, 0, S(""));
+    test(S(""), 0, SV("12345"), 4, 1, S("5"));
+    test(S(""), 0, SV("12345"), 4, 2, S("5"));
+    test(S(""), 0, SV("12345"), 5, 0, S(""));
+    test(S(""), 0, SV("12345"), 5, 1, S(""));
+    test(S(""), 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S(""), 0, SV("1234567890"), 0, 0, S(""));
+    test(S(""), 0, SV("1234567890"), 0, 1, S("1"));
+    test(S(""), 0, SV("1234567890"), 0, 5, S("12345"));
+    test(S(""), 0, SV("1234567890"), 0, 9, S("123456789"));
+    test(S(""), 0, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S(""), 0, SV("1234567890"), 1, 0, S(""));
+    test(S(""), 0, SV("1234567890"), 1, 1, S("2"));
+    test(S(""), 0, SV("1234567890"), 1, 4, S("2345"));
+    test(S(""), 0, SV("1234567890"), 1, 8, S("23456789"));
+    test(S(""), 0, SV("1234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, SV("1234567890"), 1, 10, S("234567890"));
+    test(S(""), 0, SV("1234567890"), 5, 0, S(""));
+    test(S(""), 0, SV("1234567890"), 5, 1, S("6"));
+    test(S(""), 0, SV("1234567890"), 5, 2, S("67"));
+    test(S(""), 0, SV("1234567890"), 5, 4, S("6789"));
+    test(S(""), 0, SV("1234567890"), 5, 5, S("67890"));
+    test(S(""), 0, SV("1234567890"), 5, 6, S("67890"));
+    test(S(""), 0, SV("1234567890"), 9, 0, S(""));
+    test(S(""), 0, SV("1234567890"), 9, 1, S("0"));
+    test(S(""), 0, SV("1234567890"), 9, 2, S("0"));
+    test(S(""), 0, SV("1234567890"), 10, 0, S(""));
+    test(S(""), 0, SV("1234567890"), 10, 1, S(""));
+    test(S(""), 0, SV("1234567890"), 11, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test1()
+{
+    test(S(""), 0, SV("12345678901234567890"), 0, 0, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S(""), 0, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S(""), 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 1, 0, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(""), 0, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S(""), 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 10, 0, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S(""), 0, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S(""), 0, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S(""), 0, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S(""), 0, SV("12345678901234567890"), 19, 0, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S(""), 0, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S(""), 0, SV("12345678901234567890"), 20, 0, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 20, 1, S(""));
+    test(S(""), 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S(""), 1, SV(""), 0, 0, S("can't happen"));
+    test(S(""), 1, SV(""), 0, 1, S("can't happen"));
+    test(S(""), 1, SV(""), 1, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 1, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 2, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 4, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 5, S("can't happen"));
+    test(S(""), 1, SV("12345"), 0, 6, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 1, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 2, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 3, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 4, S("can't happen"));
+    test(S(""), 1, SV("12345"), 1, 5, S("can't happen"));
+    test(S(""), 1, SV("12345"), 2, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 2, 1, S("can't happen"));
+    test(S(""), 1, SV("12345"), 2, 2, S("can't happen"));
+    test(S(""), 1, SV("12345"), 2, 3, S("can't happen"));
+    test(S(""), 1, SV("12345"), 2, 4, S("can't happen"));
+    test(S(""), 1, SV("12345"), 4, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 4, 1, S("can't happen"));
+    test(S(""), 1, SV("12345"), 4, 2, S("can't happen"));
+    test(S(""), 1, SV("12345"), 5, 0, S("can't happen"));
+    test(S(""), 1, SV("12345"), 5, 1, S("can't happen"));
+    test(S(""), 1, SV("12345"), 6, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test2()
+{
+    test(S(""), 1, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S(""), 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 0, SV(""), 0, 1, S("abcde"));
+}
+
+template <class S, class SV>
+void test3()
+{
+    test(S("abcde"), 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, SV("12345"), 0, 2, S("12abcde"));
+    test(S("abcde"), 0, SV("12345"), 0, 4, S("1234abcde"));
+    test(S("abcde"), 0, SV("12345"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, SV("12345"), 0, 6, S("12345abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 2, S("23abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 3, S("234abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, SV("12345"), 1, 5, S("2345abcde"));
+    test(S("abcde"), 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 2, 1, S("3abcde"));
+    test(S("abcde"), 0, SV("12345"), 2, 2, S("34abcde"));
+    test(S("abcde"), 0, SV("12345"), 2, 3, S("345abcde"));
+    test(S("abcde"), 0, SV("12345"), 2, 4, S("345abcde"));
+    test(S("abcde"), 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 4, 1, S("5abcde"));
+    test(S("abcde"), 0, SV("12345"), 4, 2, S("5abcde"));
+    test(S("abcde"), 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 9, S("123456789abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 0, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 8, S("23456789abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 1, 10, S("234567890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 1, S("6abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 2, S("67abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 4, S("6789abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 5, S("67890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 5, 6, S("67890abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 9, 1, S("0abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 9, 2, S("0abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 1, S("1abcde"));
+}
+
+template <class S, class SV>
+void test4()
+{
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 1, S("1abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 5, S("12345abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 9, S("123456789abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 10, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 19, 1, S("0abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 19, 2, S("0abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 1, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, SV("12345"), 0, 2, S("a12bcde"));
+    test(S("abcde"), 1, SV("12345"), 0, 4, S("a1234bcde"));
+    test(S("abcde"), 1, SV("12345"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, SV("12345"), 0, 6, S("a12345bcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 2, S("a23bcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 3, S("a234bcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, SV("12345"), 1, 5, S("a2345bcde"));
+    test(S("abcde"), 1, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 2, 1, S("a3bcde"));
+    test(S("abcde"), 1, SV("12345"), 2, 2, S("a34bcde"));
+    test(S("abcde"), 1, SV("12345"), 2, 3, S("a345bcde"));
+    test(S("abcde"), 1, SV("12345"), 2, 4, S("a345bcde"));
+    test(S("abcde"), 1, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 4, 1, S("a5bcde"));
+    test(S("abcde"), 1, SV("12345"), 4, 2, S("a5bcde"));
+    test(S("abcde"), 1, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 0, 1, S("a1bcde"));
+}
+
+template <class S, class SV>
+void test5()
+{
+    test(S("abcde"), 1, SV("1234567890"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 0, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 0, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 8, S("a23456789bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 1, 10, S("a234567890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 1, S("a6bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 2, S("a67bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 4, S("a6789bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 5, S("a67890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 5, 6, S("a67890bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 9, 1, S("a0bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 9, 2, S("a0bcde"));
+    test(S("abcde"), 1, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 1, S("a1bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 5, S("a12345bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 10, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 19, 1, S("a0bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 19, 2, S("a0bcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 2, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, SV("12345"), 0, 0, S("abcde"));
+}
+
+template <class S, class SV>
+void test6()
+{
+    test(S("abcde"), 2, SV("12345"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, SV("12345"), 0, 2, S("ab12cde"));
+    test(S("abcde"), 2, SV("12345"), 0, 4, S("ab1234cde"));
+    test(S("abcde"), 2, SV("12345"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, SV("12345"), 0, 6, S("ab12345cde"));
+    test(S("abcde"), 2, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, SV("12345"), 1, 2, S("ab23cde"));
+    test(S("abcde"), 2, SV("12345"), 1, 3, S("ab234cde"));
+    test(S("abcde"), 2, SV("12345"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, SV("12345"), 1, 5, S("ab2345cde"));
+    test(S("abcde"), 2, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345"), 2, 1, S("ab3cde"));
+    test(S("abcde"), 2, SV("12345"), 2, 2, S("ab34cde"));
+    test(S("abcde"), 2, SV("12345"), 2, 3, S("ab345cde"));
+    test(S("abcde"), 2, SV("12345"), 2, 4, S("ab345cde"));
+    test(S("abcde"), 2, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345"), 4, 1, S("ab5cde"));
+    test(S("abcde"), 2, SV("12345"), 4, 2, S("ab5cde"));
+    test(S("abcde"), 2, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 0, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 8, S("ab23456789cde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 1, 10, S("ab234567890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 1, S("ab6cde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 2, S("ab67cde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 4, S("ab6789cde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 5, S("ab67890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 5, 6, S("ab67890cde"));
+    test(S("abcde"), 2, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 9, 1, S("ab0cde"));
+    test(S("abcde"), 2, SV("1234567890"), 9, 2, S("ab0cde"));
+    test(S("abcde"), 2, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789cde"));
+}
+
+template <class S, class SV>
+void test7()
+{
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 18, S("ab234567890123456789cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 1, S("ab1cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 5, S("ab12345cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 10, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 19, 1, S("ab0cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 19, 2, S("ab0cde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 4, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 4, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 4, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, SV("12345"), 0, 2, S("abcd12e"));
+    test(S("abcde"), 4, SV("12345"), 0, 4, S("abcd1234e"));
+    test(S("abcde"), 4, SV("12345"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, SV("12345"), 0, 6, S("abcd12345e"));
+    test(S("abcde"), 4, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, SV("12345"), 1, 2, S("abcd23e"));
+    test(S("abcde"), 4, SV("12345"), 1, 3, S("abcd234e"));
+    test(S("abcde"), 4, SV("12345"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, SV("12345"), 1, 5, S("abcd2345e"));
+    test(S("abcde"), 4, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 2, 1, S("abcd3e"));
+    test(S("abcde"), 4, SV("12345"), 2, 2, S("abcd34e"));
+    test(S("abcde"), 4, SV("12345"), 2, 3, S("abcd345e"));
+    test(S("abcde"), 4, SV("12345"), 2, 4, S("abcd345e"));
+    test(S("abcde"), 4, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 4, 1, S("abcd5e"));
+    test(S("abcde"), 4, SV("12345"), 4, 2, S("abcd5e"));
+    test(S("abcde"), 4, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 4, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, SV("1234567890"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, SV("1234567890"), 0, 9, S("abcd123456789e"));
+}
+
+template <class S, class SV>
+void test8()
+{
+    test(S("abcde"), 4, SV("1234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, SV("1234567890"), 0, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 8, S("abcd23456789e"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, SV("1234567890"), 1, 10, S("abcd234567890e"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 1, S("abcd6e"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 2, S("abcd67e"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 4, S("abcd6789e"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 5, S("abcd67890e"));
+    test(S("abcde"), 4, SV("1234567890"), 5, 6, S("abcd67890e"));
+    test(S("abcde"), 4, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 9, 1, S("abcd0e"));
+    test(S("abcde"), 4, SV("1234567890"), 9, 2, S("abcd0e"));
+    test(S("abcde"), 4, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 19, S("abcd1234567890123456789e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 20, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 0, 21, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 18, S("abcd234567890123456789e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 19, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 1, 20, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 1, S("abcd1e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 5, S("abcd12345e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 9, S("abcd123456789e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 10, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 19, 1, S("abcd0e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 19, 2, S("abcd0e"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 5, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 5, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 5, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, SV("12345"), 0, 2, S("abcde12"));
+}
+
+template <class S, class SV>
+void test9()
+{
+    test(S("abcde"), 5, SV("12345"), 0, 4, S("abcde1234"));
+    test(S("abcde"), 5, SV("12345"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, SV("12345"), 0, 6, S("abcde12345"));
+    test(S("abcde"), 5, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, SV("12345"), 1, 2, S("abcde23"));
+    test(S("abcde"), 5, SV("12345"), 1, 3, S("abcde234"));
+    test(S("abcde"), 5, SV("12345"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, SV("12345"), 1, 5, S("abcde2345"));
+    test(S("abcde"), 5, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 2, 1, S("abcde3"));
+    test(S("abcde"), 5, SV("12345"), 2, 2, S("abcde34"));
+    test(S("abcde"), 5, SV("12345"), 2, 3, S("abcde345"));
+    test(S("abcde"), 5, SV("12345"), 2, 4, S("abcde345"));
+    test(S("abcde"), 5, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 4, 1, S("abcde5"));
+    test(S("abcde"), 5, SV("12345"), 4, 2, S("abcde5"));
+    test(S("abcde"), 5, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, SV("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, SV("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcde"), 5, SV("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcde"), 5, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcde"), 5, SV("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcde"), 5, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+}
+
+template <class S, class SV>
+void test10()
+{
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 6, SV(""), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, SV(""), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 0, 11, S("can't happen"));
+}
+
+template <class S, class SV>
+void test11()
+{
+    test(S("abcde"), 6, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcde"), 6, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 0, 2, S("12abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 0, 4, S("1234abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 0, 5, S("12345abcdefghij"));
+}
+
+template <class S, class SV>
+void test12()
+{
+    test(S("abcdefghij"), 0, SV("12345"), 0, 6, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 2, S("23abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 3, S("234abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 1, 5, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 2, 1, S("3abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 2, 2, S("34abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 2, 3, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 2, 4, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 4, 1, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 4, 2, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 0, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 8, S("23456789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 1, 10, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 1, S("6abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 2, S("67abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 4, S("6789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 5, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 5, 6, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 9, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 9, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 1, S("2abcdefghij"));
+}
+
+template <class S, class SV>
+void test13()
+{
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 10, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 19, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 19, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 2, S("a12bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 4, S("a1234bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 0, 6, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 2, S("a23bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 3, S("a234bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 1, 5, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 2, 1, S("a3bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 2, 2, S("a34bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 2, 3, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 2, 4, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 4, 1, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 4, 2, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 0, 11, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 1, S("a2bcdefghij"));
+}
+
+template <class S, class SV>
+void test14()
+{
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 8, S("a23456789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 1, 10, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 1, S("a6bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 2, S("a67bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 4, S("a6789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 5, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 5, 6, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 9, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 9, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 10, 11, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 19, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 19, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 2, S("abcde12fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 4, S("abcde1234fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 0, 6, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 1, 0, S("abcdefghij"));
+}
+
+template <class S, class SV>
+void test15()
+{
+    test(S("abcdefghij"), 5, SV("12345"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 1, 2, S("abcde23fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 1, 3, S("abcde234fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 1, 5, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 2, 1, S("abcde3fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 2, 2, S("abcde34fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 2, 3, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 2, 4, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 4, 1, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 4, 2, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 0, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 8, S("abcde23456789fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 1, 10, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 1, S("abcde6fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 2, S("abcde67fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 4, S("abcde6789fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 5, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 5, 6, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 9, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 9, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789fghij"));
+}
+
+template <class S, class SV>
+void test16()
+{
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 10, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 19, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 19, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 2, S("abcdefghi12j"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 4, S("abcdefghi1234j"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 0, 6, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 2, S("abcdefghi23j"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 3, S("abcdefghi234j"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 1, 5, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 2, 1, S("abcdefghi3j"));
+    test(S("abcdefghij"), 9, SV("12345"), 2, 2, S("abcdefghi34j"));
+    test(S("abcdefghij"), 9, SV("12345"), 2, 3, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 2, 4, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 4, 1, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, SV("12345"), 4, 2, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 0, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 8, S("abcdefghi23456789j"));
+}
+
+template <class S, class SV>
+void test17()
+{
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 1, 10, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 1, S("abcdefghi6j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 2, S("abcdefghi67j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 4, S("abcdefghi6789j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 5, S("abcdefghi67890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 5, 6, S("abcdefghi67890j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 9, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 9, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 19, S("abcdefghi1234567890123456789j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 20, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 0, 21, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 18, S("abcdefghi234567890123456789j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 19, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 1, 20, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 10, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 19, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 19, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, SV("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, SV("12345"), 1, 2, S("abcdefghij23"));
+}
+
+template <class S, class SV>
+void test18()
+{
+    test(S("abcdefghij"), 10, SV("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghij"), 10, SV("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, SV("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghij"), 10, SV("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghij"), 10, SV("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, SV("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 4, 1, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, SV("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 4, S("abcdefghij6789"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+}
+
+template <class S, class SV>
+void test19()
+{
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV(""), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV(""), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 1, 10, S("can't happen"));
+}
+
+template <class S, class SV>
+void test20()
+{
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 2, S("12abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 4, S("1234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 0, 6, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 2, S("23abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 3, S("234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 4, S("2345abcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test21()
+{
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 1, 5, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 2, 1, S("3abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 2, 2, S("34abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 2, 3, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 2, 4, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 4, 1, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 4, 2, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 0, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 4, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 8, S("23456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 1, 10, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 1, S("6abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 2, S("67abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 4, S("6789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 5, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 5, 6, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 9, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 9, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 1, S("1abcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test22()
+{
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 10, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 19, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 19, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 2, S("a12bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 4, S("a1234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 0, 6, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 2, S("a23bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 3, S("a234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 1, 5, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 2, 1, S("a3bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 2, 2, S("a34bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 2, 3, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 2, 4, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 4, 1, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 4, 2, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 0, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 8, S("a23456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 1, 10, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 1, S("a6bcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test23()
+{
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 2, S("a67bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 4, S("a6789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 5, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 5, 6, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 9, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 9, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 10, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 19, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 19, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 2, S("abcdefghij12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 4, S("abcdefghij1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, 6, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 2, S("abcdefghij23klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 3, S("abcdefghij234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, 5, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test24()
+{
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 2, 1, S("abcdefghij3klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 2, 2, S("abcdefghij34klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 2, 3, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 2, 4, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 4, 1, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 4, 2, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 9, S("abcdefghij123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 0, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 8, S("abcdefghij23456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 1, 10, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 1, S("abcdefghij6klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 2, S("abcdefghij67klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 4, S("abcdefghij6789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 5, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 5, 6, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 9, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 9, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789klmnopqrst"));
+}
+
+template <class S, class SV>
+void test25()
+{
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 19, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 19, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 2, S("abcdefghijklmnopqrs12t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 4, S("abcdefghijklmnopqrs1234t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 0, 6, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 2, S("abcdefghijklmnopqrs23t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 3, S("abcdefghijklmnopqrs234t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 1, 5, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 2, 1, S("abcdefghijklmnopqrs3t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 2, 2, S("abcdefghijklmnopqrs34t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 2, 3, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 2, 4, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 4, 1, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 4, 2, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrs23456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrs6t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrs67t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrs6789t"));
+}
+
+template <class S, class SV>
+void test26()
+{
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrs1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrs234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 2, S("abcdefghijklmnopqrst12"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 4, S("abcdefghijklmnopqrst1234"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 0, 6, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 2, S("abcdefghijklmnopqrst23"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 3, S("abcdefghijklmnopqrst234"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 1, 5, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 2, 1, S("abcdefghijklmnopqrst3"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 2, 2, S("abcdefghijklmnopqrst34"));
+}
+
+template <class S, class SV>
+void test27()
+{
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 2, 3, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 2, 4, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 4, 1, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 4, 2, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrst23456789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrst6"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrst67"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrst6789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrst1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrst234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrst1234567890"));
+}
+
+template <class S, class SV>
+void test28()
+{
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV(""), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV(""), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 5, 6, S("can't happen"));
+}
+
+template <class S, class SV>
+void test29()
+{
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), 21, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test30()
+{
+    test_npos(S(""), 0, SV("12345678901234567890"),  0, S("12345678901234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"),  1, S( "2345678901234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"),  2, S(  "345678901234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"),  3, S(   "45678901234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"),  5, S(     "678901234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"), 10, S(          "1234567890"));
+    test_npos(S(""), 0, SV("12345678901234567890"), 21, S("can't happen"));
+    test_npos(S("abcdefghijklmnopqrst"), 10, SV("12345"), 0, S("abcdefghij12345klmnopqrst"));
+    test_npos(S("abcdefghijklmnopqrst"), 10, SV("12345"), 1, S("abcdefghij2345klmnopqrst"));
+    test_npos(S("abcdefghijklmnopqrst"), 10, SV("12345"), 3, S("abcdefghij45klmnopqrst"));
+    test_npos(S("abcdefghijklmnopqrst"), 10, SV("12345"), 5, S("abcdefghijklmnopqrst"));
+    test_npos(S("abcdefghijklmnopqrst"), 10, SV("12345"), 6, S("can't happen"));
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test0<S, SV>();
+    test1<S, SV>();
+    test2<S, SV>();
+    test3<S, SV>();
+    test4<S, SV>();
+    test5<S, SV>();
+    test6<S, SV>();
+    test7<S, SV>();
+    test8<S, SV>();
+    test9<S, SV>();
+    test10<S, SV>();
+    test11<S, SV>();
+    test12<S, SV>();
+    test13<S, SV>();
+    test14<S, SV>();
+    test15<S, SV>();
+    test16<S, SV>();
+    test17<S, SV>();
+    test18<S, SV>();
+    test19<S, SV>();
+    test20<S, SV>();
+    test21<S, SV>();
+    test22<S, SV>();
+    test23<S, SV>();
+    test24<S, SV>();
+    test25<S, SV>();
+    test26<S, SV>();
+    test27<S, SV>();
+    test28<S, SV>();
+    test29<S, SV>();
+    test30<S, SV>();
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char>> SV;
+    test0<S, SV>();
+    test1<S, SV>();
+    test2<S, SV>();
+    test3<S, SV>();
+    test4<S, SV>();
+    test5<S, SV>();
+    test6<S, SV>();
+    test7<S, SV>();
+    test8<S, SV>();
+    test9<S, SV>();
+    test10<S, SV>();
+    test11<S, SV>();
+    test12<S, SV>();
+    test13<S, SV>();
+    test14<S, SV>();
+    test15<S, SV>();
+    test16<S, SV>();
+    test17<S, SV>();
+    test18<S, SV>();
+    test19<S, SV>();
+    test20<S, SV>();
+    test21<S, SV>();
+    test22<S, SV>();
+    test23<S, SV>();
+    test24<S, SV>();
+    test25<S, SV>();
+    test26<S, SV>();
+    test27<S, SV>();
+    test28<S, SV>();
+    test29<S, SV>();
+    test30<S, SV>();
+    }
+#endif
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    S s;
+    SV sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s.insert(0, "CDEF", 0);    // calls insert(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.insert(0, "QRST", 0, std::string::npos); // calls insert(string("QRST"), pos, npos)
+    assert(s == "QRST");
+    s.clear();
+
+    s.insert(0, sv, 0);  // calls insert(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.insert(0, sv, 0, std::string::npos);   // calls insert(T, pos, npos)
+    assert(s == sv);
+    s.clear();
+
+    s.insert(0, arr, 0);     // calls insert(const char *, len)
+    assert(s == "");
+    s.clear();
+
+    s.insert(0, arr, 0, std::string::npos);    // calls insert(string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    s.clear();
+
+    s.insert(0, arr, 0);     // calls insert(const char *, len)
+    assert(s == "");
+    s.clear();
+    }
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer.pass.cpp
index faab5bd92672..e49f57a7f9ad 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -24,20 +23,29 @@ template <class S>
 void
 test(S s, typename S::size_type pos, const typename S::value_type* str, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.insert(pos, str);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.insert(pos, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 int main()
@@ -210,4 +218,20 @@ int main()
     test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", S("can't happen"));
     }
 #endif
+
+	{ // test inserting into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.insert(0, s_short.c_str());
+	assert(s_short == "123/123/");
+	s_short.insert(0, s_short.c_str());
+	assert(s_short == "123/123/123/123/");
+	s_short.insert(0, s_short.c_str());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.insert(0, s_long.c_str());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer_size.pass.cpp
index 30d3df9f259f..a42a60ddcdb4 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_pointer_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -25,20 +24,29 @@ void
 test(S s, typename S::size_type pos, const typename S::value_type* str,
      typename S::size_type n, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.insert(pos, str, n);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.insert(pos, str, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 int main()
@@ -691,4 +699,20 @@ int main()
     test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 20, S("can't happen"));
     }
 #endif
+
+	{ // test inserting into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.insert(0, s_short.data(), s_short.size());
+	assert(s_short == "123/123/");
+	s_short.insert(0, s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/");
+	s_short.insert(0, s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.insert(0, s_long.data(), s_long.size());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
index 04ea1d376940..a769604c6ff9 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -25,20 +24,29 @@ void
 test(S s, typename S::size_type pos, typename S::size_type n,
      typename S::value_type str, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.insert(pos, n, str);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.insert(pos, n, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 int main()
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_string.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_string.pass.cpp
index 1945871b99ac..e7c5ecdc9c1b 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/size_string.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_string.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -24,20 +23,29 @@ template <class S>
 void
 test(S s, typename S::size_type pos, S str, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.insert(pos, str);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.insert(pos, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 int main()
diff --git a/test/std/strings/basic.string/string.modifiers/string_insert/size_string_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_insert/size_string_size_size.pass.cpp
index 32485db478d8..67ba7ec108f1 100644
--- a/test/std/strings/basic.string/string.modifiers/string_insert/size_string_size_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_insert/size_string_size_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -27,40 +26,58 @@ void
 test(S s, typename S::size_type pos1, S str, typename S::size_type pos2,
      typename S::size_type n, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos1 <= old_size && pos2 <= str.size())
     {
         s.insert(pos1, str, pos2, n);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos1 <= old_size && pos2 <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos1 > old_size || pos2 > str.size());
-        assert(s == s0);
+        try
+        {
+            s.insert(pos1, str, pos2, n);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > str.size());
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
 void
 test_npos(S s, typename S::size_type pos1, S str, typename S::size_type pos2, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos1 <= old_size && pos2 <= str.size())
     {
         s.insert(pos1, str, pos2);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos1 <= old_size && pos2 <= str.size());
         assert(s == expected);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos1 > old_size || pos2 > str.size());
-        assert(s == s0);
+        try
+        {
+            s.insert(pos1, str, pos2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > str.size());
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_iter_iter.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_iter_iter.pass.cpp
index cc37e79c7932..e456d395220b 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_iter_iter.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_iter_iter.pass.cpp
@@ -1007,4 +1007,34 @@ int main()
     test_exceptions(S("abcdefghijklmnopqrst"), 10, 5, TIter(s, s+10, 6, TIter::TAComparison), TIter());
 	}
 #endif
+
+	{ // test replacing into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.begin(), s_short.end());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.replace(s_long.begin(), s_long.begin(), s_long.begin(), s_long.end());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
+
+	{ // test assigning a different type
+    typedef std::string S;
+	const uint8_t pc[] = "ABCD";
+	uint8_t        p[] = "EFGH";
+
+	S s;
+	s.replace(s.begin(), s.end(), pc, pc + 4);
+	assert(s == "ABCD");
+
+	s.clear();
+	s.replace(s.begin(), s.end(), p, p + 4);
+	assert(s == "EFGH");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer.pass.cpp
index 730fc1a501cf..f642d3a4f921 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer.pass.cpp
@@ -282,4 +282,20 @@ int main()
     test2<S>();
     }
 #endif
+
+	{ // test replacing into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.c_str());
+	assert(s_short == "123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.c_str());
+	assert(s_short == "123/123/123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.c_str());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.replace(s_long.begin(), s_long.begin(), s_long.c_str());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer_size.pass.cpp
index 4a910e499819..695036807223 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/iter_iter_pointer_size.pass.cpp
@@ -972,4 +972,20 @@ int main()
     test8<S>();
     }
 #endif
+
+	{ // test replacing into self
+    typedef std::string S;
+	S s_short = "123/";
+	S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
+
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.data(), s_short.size());
+	assert(s_short == "123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/");
+	s_short.replace(s_short.begin(), s_short.begin(), s_short.data(), s_short.size());
+	assert(s_short == "123/123/123/123/123/123/123/123/");
+
+	s_long.replace(s_long.begin(), s_long.begin(), s_long.data(), s_long.size());
+	assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
+	}
 }
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_T_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_T_size_size.pass.cpp
new file mode 100644
index 000000000000..840b7614f482
--- /dev/null
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_T_size_size.pass.cpp
@@ -0,0 +1,6022 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template <class T>
+//    basic_string& replace(size_type pos1, size_type n1, const T& t,
+//                          size_type pos2, size_type n=npos);
+//
+//  Mostly we're testing string_view here
+
+#include <string>
+#include <stdexcept>
+#include <algorithm>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S, class SV>
+void
+test(S s, typename S::size_type pos1, typename S::size_type n1,
+     SV sv, typename S::size_type pos2, typename S::size_type n2,
+     S expected)
+{
+    static_assert((!std::is_same<S, SV>::value), "");
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos1 <= old_size && pos2 <= sv.size())
+    {
+        s.replace(pos1, n1, sv, pos2, n2);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+        typename S::size_type xlen = std::min(n1, old_size - pos1);
+        typename S::size_type rlen = std::min(n2, sv.size() - pos2);
+        assert(s.size() == old_size - xlen + rlen);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.replace(pos1, n1, sv, pos2, n2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > sv.size());
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+template <class S, class SV>
+void
+test_npos(S s, typename S::size_type pos1, typename S::size_type n1,
+          SV sv, typename S::size_type pos2,
+          S expected)
+{
+    static_assert((!std::is_same<S, SV>::value), "");
+    const typename S::size_type old_size = s.size();
+    S s0 = s;
+    if (pos1 <= old_size && pos2 <= sv.size())
+    {
+        s.replace(pos1, n1, sv, pos2);
+        LIBCPP_ASSERT(s.__invariants());
+        assert(s == expected);
+        typename S::size_type xlen = std::min(n1, old_size - pos1);
+        typename S::size_type rlen = std::min(S::npos, sv.size() - pos2);
+        assert(s.size() == old_size - xlen + rlen);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
+    {
+        try
+        {
+            s.replace(pos1, n1, sv, pos2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > sv.size());
+            assert(s == s0);
+        }
+    }
+#endif
+}
+
+
+template <class S, class SV>
+void test0()
+{
+    test(S(""), 0, 0, SV(""), 0, 0, S(""));
+    test(S(""), 0, 0, SV(""), 0, 1, S(""));
+    test(S(""), 0, 0, SV(""), 1, 0, S("can't happen"));
+    test(S(""), 0, 0, SV("12345"), 0, 0, S(""));
+    test(S(""), 0, 0, SV("12345"), 0, 1, S("1"));
+    test(S(""), 0, 0, SV("12345"), 0, 2, S("12"));
+    test(S(""), 0, 0, SV("12345"), 0, 4, S("1234"));
+    test(S(""), 0, 0, SV("12345"), 0, 5, S("12345"));
+    test(S(""), 0, 0, SV("12345"), 0, 6, S("12345"));
+    test(S(""), 0, 0, SV("12345"), 1, 0, S(""));
+    test(S(""), 0, 0, SV("12345"), 1, 1, S("2"));
+    test(S(""), 0, 0, SV("12345"), 1, 2, S("23"));
+    test(S(""), 0, 0, SV("12345"), 1, 3, S("234"));
+    test(S(""), 0, 0, SV("12345"), 1, 4, S("2345"));
+    test(S(""), 0, 0, SV("12345"), 1, 5, S("2345"));
+    test(S(""), 0, 0, SV("12345"), 2, 0, S(""));
+    test(S(""), 0, 0, SV("12345"), 2, 1, S("3"));
+    test(S(""), 0, 0, SV("12345"), 2, 2, S("34"));
+    test(S(""), 0, 0, SV("12345"), 2, 3, S("345"));
+    test(S(""), 0, 0, SV("12345"), 2, 4, S("345"));
+    test(S(""), 0, 0, SV("12345"), 4, 0, S(""));
+    test(S(""), 0, 0, SV("12345"), 4, 1, S("5"));
+    test(S(""), 0, 0, SV("12345"), 4, 2, S("5"));
+    test(S(""), 0, 0, SV("12345"), 5, 0, S(""));
+    test(S(""), 0, 0, SV("12345"), 5, 1, S(""));
+    test(S(""), 0, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S(""), 0, 0, SV("1234567890"), 0, 0, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 0, 1, S("1"));
+    test(S(""), 0, 0, SV("1234567890"), 0, 5, S("12345"));
+    test(S(""), 0, 0, SV("1234567890"), 0, 9, S("123456789"));
+    test(S(""), 0, 0, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, 0, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S(""), 0, 0, SV("1234567890"), 1, 0, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 1, 1, S("2"));
+    test(S(""), 0, 0, SV("1234567890"), 1, 4, S("2345"));
+    test(S(""), 0, 0, SV("1234567890"), 1, 8, S("23456789"));
+    test(S(""), 0, 0, SV("1234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, 0, SV("1234567890"), 1, 10, S("234567890"));
+    test(S(""), 0, 0, SV("1234567890"), 5, 0, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 5, 1, S("6"));
+    test(S(""), 0, 0, SV("1234567890"), 5, 2, S("67"));
+    test(S(""), 0, 0, SV("1234567890"), 5, 4, S("6789"));
+    test(S(""), 0, 0, SV("1234567890"), 5, 5, S("67890"));
+    test(S(""), 0, 0, SV("1234567890"), 5, 6, S("67890"));
+    test(S(""), 0, 0, SV("1234567890"), 9, 0, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 9, 1, S("0"));
+    test(S(""), 0, 0, SV("1234567890"), 9, 2, S("0"));
+    test(S(""), 0, 0, SV("1234567890"), 10, 0, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 10, 1, S(""));
+    test(S(""), 0, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 0, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 0, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 0, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 19, 0, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S(""), 0, 0, SV("12345678901234567890"), 20, 0, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 20, 1, S(""));
+    test(S(""), 0, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S(""), 0, 1, SV(""), 0, 0, S(""));
+    test(S(""), 0, 1, SV(""), 0, 1, S(""));
+    test(S(""), 0, 1, SV(""), 1, 0, S("can't happen"));
+    test(S(""), 0, 1, SV("12345"), 0, 0, S(""));
+    test(S(""), 0, 1, SV("12345"), 0, 1, S("1"));
+    test(S(""), 0, 1, SV("12345"), 0, 2, S("12"));
+    test(S(""), 0, 1, SV("12345"), 0, 4, S("1234"));
+    test(S(""), 0, 1, SV("12345"), 0, 5, S("12345"));
+    test(S(""), 0, 1, SV("12345"), 0, 6, S("12345"));
+    test(S(""), 0, 1, SV("12345"), 1, 0, S(""));
+    test(S(""), 0, 1, SV("12345"), 1, 1, S("2"));
+    test(S(""), 0, 1, SV("12345"), 1, 2, S("23"));
+    test(S(""), 0, 1, SV("12345"), 1, 3, S("234"));
+    test(S(""), 0, 1, SV("12345"), 1, 4, S("2345"));
+    test(S(""), 0, 1, SV("12345"), 1, 5, S("2345"));
+    test(S(""), 0, 1, SV("12345"), 2, 0, S(""));
+    test(S(""), 0, 1, SV("12345"), 2, 1, S("3"));
+    test(S(""), 0, 1, SV("12345"), 2, 2, S("34"));
+    test(S(""), 0, 1, SV("12345"), 2, 3, S("345"));
+    test(S(""), 0, 1, SV("12345"), 2, 4, S("345"));
+    test(S(""), 0, 1, SV("12345"), 4, 0, S(""));
+    test(S(""), 0, 1, SV("12345"), 4, 1, S("5"));
+    test(S(""), 0, 1, SV("12345"), 4, 2, S("5"));
+    test(S(""), 0, 1, SV("12345"), 5, 0, S(""));
+    test(S(""), 0, 1, SV("12345"), 5, 1, S(""));
+    test(S(""), 0, 1, SV("12345"), 6, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test1()
+{
+    test(S(""), 0, 1, SV("1234567890"), 0, 0, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 0, 1, S("1"));
+    test(S(""), 0, 1, SV("1234567890"), 0, 5, S("12345"));
+    test(S(""), 0, 1, SV("1234567890"), 0, 9, S("123456789"));
+    test(S(""), 0, 1, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, 1, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S(""), 0, 1, SV("1234567890"), 1, 0, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 1, 1, S("2"));
+    test(S(""), 0, 1, SV("1234567890"), 1, 4, S("2345"));
+    test(S(""), 0, 1, SV("1234567890"), 1, 8, S("23456789"));
+    test(S(""), 0, 1, SV("1234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, 1, SV("1234567890"), 1, 10, S("234567890"));
+    test(S(""), 0, 1, SV("1234567890"), 5, 0, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 5, 1, S("6"));
+    test(S(""), 0, 1, SV("1234567890"), 5, 2, S("67"));
+    test(S(""), 0, 1, SV("1234567890"), 5, 4, S("6789"));
+    test(S(""), 0, 1, SV("1234567890"), 5, 5, S("67890"));
+    test(S(""), 0, 1, SV("1234567890"), 5, 6, S("67890"));
+    test(S(""), 0, 1, SV("1234567890"), 9, 0, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 9, 1, S("0"));
+    test(S(""), 0, 1, SV("1234567890"), 9, 2, S("0"));
+    test(S(""), 0, 1, SV("1234567890"), 10, 0, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 10, 1, S(""));
+    test(S(""), 0, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 0, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 0, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 0, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 19, 0, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S(""), 0, 1, SV("12345678901234567890"), 20, 0, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 20, 1, S(""));
+    test(S(""), 0, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S(""), 1, 0, SV(""), 0, 0, S("can't happen"));
+    test(S(""), 1, 0, SV(""), 0, 1, S("can't happen"));
+    test(S(""), 1, 0, SV(""), 1, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 4, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 5, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 0, 6, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 3, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 4, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 1, 5, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 2, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 2, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 2, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 2, 3, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 2, 4, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 4, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 4, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 4, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 5, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 5, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 1, S("can't happen"));
+}
+
+template <class S, class SV>
+void test2()
+{
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S(""), 1, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 0, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 2, S("12abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 4, S("1234abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 0, 6, S("12345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 2, S("23abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 3, S("234abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 1, 5, S("2345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 2, 1, S("3abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 2, 2, S("34abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 2, 3, S("345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 2, 4, S("345abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 4, 1, S("5abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 4, 2, S("5abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 9, S("123456789abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 0, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 8, S("23456789abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 1, 10, S("234567890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 1, S("6abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 2, S("67abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 4, S("6789abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 5, S("67890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 5, 6, S("67890abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 9, 1, S("0abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 9, 2, S("0abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 0, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 1, S("1abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 5, S("12345abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 9, S("123456789abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 10, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 19, 1, S("0abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 19, 2, S("0abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 0, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 1, SV(""), 0, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV(""), 0, 1, S("bcde"));
+    test(S("abcde"), 0, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 1, SV("12345"), 0, 0, S("bcde"));
+}
+
+template <class S, class SV>
+void test3()
+{
+    test(S("abcde"), 0, 1, SV("12345"), 0, 1, S("1bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 0, 2, S("12bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 0, 4, S("1234bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 0, 5, S("12345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 0, 6, S("12345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 1, S("2bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 2, S("23bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 3, S("234bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 4, S("2345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 1, 5, S("2345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 2, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 2, 1, S("3bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 2, 2, S("34bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 2, 3, S("345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 2, 4, S("345bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 4, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 4, 1, S("5bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 4, 2, S("5bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 5, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 5, 1, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 1, S("1bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 5, S("12345bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 9, S("123456789bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 10, S("1234567890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 0, 11, S("1234567890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 1, S("2bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 4, S("2345bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 8, S("23456789bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 9, S("234567890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 1, 10, S("234567890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 1, S("6bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 2, S("67bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 4, S("6789bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 5, S("67890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 5, 6, S("67890bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 9, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 9, 1, S("0bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 9, 2, S("0bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 10, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 10, 1, S("bcde"));
+    test(S("abcde"), 0, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 1, S("1bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 10, S("1234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 19, S("1234567890123456789bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 20, S("12345678901234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 0, 21, S("12345678901234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 1, S("2bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 9, S("234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 18, S("234567890123456789bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 19, S("2345678901234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 1, 20, S("2345678901234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 1, S("1bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 5, S("12345bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 9, S("123456789bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 10, S("1234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 10, 11, S("1234567890bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 19, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 19, 1, S("0bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 19, 2, S("0bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 20, 0, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 20, 1, S("bcde"));
+    test(S("abcde"), 0, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 2, SV(""), 0, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV(""), 0, 1, S("cde"));
+    test(S("abcde"), 0, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 1, S("1cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 2, S("12cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 4, S("1234cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 5, S("12345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 0, 6, S("12345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 1, S("2cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 2, S("23cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 3, S("234cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 4, S("2345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 1, 5, S("2345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 2, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 2, 1, S("3cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 2, 2, S("34cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 2, 3, S("345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 2, 4, S("345cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 4, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 4, 1, S("5cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 4, 2, S("5cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 5, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 5, 1, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 1, S("1cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 5, S("12345cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 9, S("123456789cde"));
+}
+
+template <class S, class SV>
+void test4()
+{
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 10, S("1234567890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 0, 11, S("1234567890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 1, S("2cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 4, S("2345cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 8, S("23456789cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 9, S("234567890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 1, 10, S("234567890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 1, S("6cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 2, S("67cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 4, S("6789cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 5, S("67890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 5, 6, S("67890cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 9, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 9, 1, S("0cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 9, 2, S("0cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 10, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 10, 1, S("cde"));
+    test(S("abcde"), 0, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 1, S("1cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 10, S("1234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 19, S("1234567890123456789cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 20, S("12345678901234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 0, 21, S("12345678901234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 1, S("2cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 9, S("234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 18, S("234567890123456789cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 19, S("2345678901234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 1, 20, S("2345678901234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 1, S("1cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 5, S("12345cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 9, S("123456789cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 10, S("1234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 10, 11, S("1234567890cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 19, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 19, 1, S("0cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 19, 2, S("0cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 20, 0, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 20, 1, S("cde"));
+    test(S("abcde"), 0, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 4, SV(""), 0, 0, S("e"));
+    test(S("abcde"), 0, 4, SV(""), 0, 1, S("e"));
+    test(S("abcde"), 0, 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 1, S("1e"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 2, S("12e"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 4, S("1234e"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 5, S("12345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 0, 6, S("12345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 1, S("2e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 2, S("23e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 3, S("234e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 4, S("2345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 1, 5, S("2345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 2, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 2, 1, S("3e"));
+    test(S("abcde"), 0, 4, SV("12345"), 2, 2, S("34e"));
+    test(S("abcde"), 0, 4, SV("12345"), 2, 3, S("345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 2, 4, S("345e"));
+    test(S("abcde"), 0, 4, SV("12345"), 4, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 4, 1, S("5e"));
+    test(S("abcde"), 0, 4, SV("12345"), 4, 2, S("5e"));
+    test(S("abcde"), 0, 4, SV("12345"), 5, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 5, 1, S("e"));
+    test(S("abcde"), 0, 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 1, S("1e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 5, S("12345e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 9, S("123456789e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 10, S("1234567890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 0, 11, S("1234567890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 1, S("2e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 4, S("2345e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 8, S("23456789e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 9, S("234567890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 1, 10, S("234567890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 1, S("6e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 2, S("67e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 4, S("6789e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 5, S("67890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 5, 6, S("67890e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 9, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 9, 1, S("0e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 9, 2, S("0e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 10, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 10, 1, S("e"));
+    test(S("abcde"), 0, 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 1, S("1e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 10, S("1234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 19, S("1234567890123456789e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 20, S("12345678901234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 0, 21, S("12345678901234567890e"));
+}
+
+template <class S, class SV>
+void test5()
+{
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 1, S("2e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 9, S("234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 18, S("234567890123456789e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 19, S("2345678901234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 1, 20, S("2345678901234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 1, S("1e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 5, S("12345e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 9, S("123456789e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 10, S("1234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 10, 11, S("1234567890e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 19, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 19, 1, S("0e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 19, 2, S("0e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 20, 0, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 20, 1, S("e"));
+    test(S("abcde"), 0, 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 5, SV(""), 0, 0, S(""));
+    test(S("abcde"), 0, 5, SV(""), 0, 1, S(""));
+    test(S("abcde"), 0, 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 1, S("1"));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 2, S("12"));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 4, S("1234"));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 5, S("12345"));
+    test(S("abcde"), 0, 5, SV("12345"), 0, 6, S("12345"));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 1, S("2"));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 2, S("23"));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 3, S("234"));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 4, S("2345"));
+    test(S("abcde"), 0, 5, SV("12345"), 1, 5, S("2345"));
+    test(S("abcde"), 0, 5, SV("12345"), 2, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 2, 1, S("3"));
+    test(S("abcde"), 0, 5, SV("12345"), 2, 2, S("34"));
+    test(S("abcde"), 0, 5, SV("12345"), 2, 3, S("345"));
+    test(S("abcde"), 0, 5, SV("12345"), 2, 4, S("345"));
+    test(S("abcde"), 0, 5, SV("12345"), 4, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 4, 1, S("5"));
+    test(S("abcde"), 0, 5, SV("12345"), 4, 2, S("5"));
+    test(S("abcde"), 0, 5, SV("12345"), 5, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 5, 1, S(""));
+    test(S("abcde"), 0, 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 0, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 9, S("123456789"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 0, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 0, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 9, 0, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcde"), 0, 5, SV("1234567890"), 10, 0, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 10, 1, S(""));
+    test(S("abcde"), 0, 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcde"), 0, 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, 6, SV(""), 0, 0, S(""));
+    test(S("abcde"), 0, 6, SV(""), 0, 1, S(""));
+    test(S("abcde"), 0, 6, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, 6, SV("12345"), 0, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 0, 1, S("1"));
+    test(S("abcde"), 0, 6, SV("12345"), 0, 2, S("12"));
+    test(S("abcde"), 0, 6, SV("12345"), 0, 4, S("1234"));
+    test(S("abcde"), 0, 6, SV("12345"), 0, 5, S("12345"));
+}
+
+template <class S, class SV>
+void test6()
+{
+    test(S("abcde"), 0, 6, SV("12345"), 0, 6, S("12345"));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 1, S("2"));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 2, S("23"));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 3, S("234"));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 4, S("2345"));
+    test(S("abcde"), 0, 6, SV("12345"), 1, 5, S("2345"));
+    test(S("abcde"), 0, 6, SV("12345"), 2, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 2, 1, S("3"));
+    test(S("abcde"), 0, 6, SV("12345"), 2, 2, S("34"));
+    test(S("abcde"), 0, 6, SV("12345"), 2, 3, S("345"));
+    test(S("abcde"), 0, 6, SV("12345"), 2, 4, S("345"));
+    test(S("abcde"), 0, 6, SV("12345"), 4, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 4, 1, S("5"));
+    test(S("abcde"), 0, 6, SV("12345"), 4, 2, S("5"));
+    test(S("abcde"), 0, 6, SV("12345"), 5, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 5, 1, S(""));
+    test(S("abcde"), 0, 6, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 0, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 9, S("123456789"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 0, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 0, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 9, 0, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcde"), 0, 6, SV("1234567890"), 10, 0, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 10, 1, S(""));
+    test(S("abcde"), 0, 6, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcde"), 0, 6, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 1, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 2, S("a12bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 4, S("a1234bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 0, 6, S("a12345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 2, S("a23bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 3, S("a234bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 1, 5, S("a2345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 2, 1, S("a3bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 2, 2, S("a34bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 2, 3, S("a345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 2, 4, S("a345bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 4, 1, S("a5bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 4, 2, S("a5bcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 0, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 1, S("a2bcde"));
+}
+
+template <class S, class SV>
+void test7()
+{
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 8, S("a23456789bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 1, 10, S("a234567890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 1, S("a6bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 2, S("a67bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 4, S("a6789bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 5, S("a67890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 5, 6, S("a67890bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 9, 1, S("a0bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 9, 2, S("a0bcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 1, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 1, S("a1bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 5, S("a12345bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 10, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 19, 1, S("a0bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 19, 2, S("a0bcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 1, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 1, SV(""), 0, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV(""), 0, 1, S("acde"));
+    test(S("abcde"), 1, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 1, S("a1cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 2, S("a12cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 4, S("a1234cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 5, S("a12345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 0, 6, S("a12345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 1, S("a2cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 2, S("a23cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 3, S("a234cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 4, S("a2345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 1, 5, S("a2345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 2, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 2, 1, S("a3cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 2, 2, S("a34cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 2, 3, S("a345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 2, 4, S("a345cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 4, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 4, 1, S("a5cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 4, 2, S("a5cde"));
+    test(S("abcde"), 1, 1, SV("12345"), 5, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 5, 1, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 1, S("a1cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 5, S("a12345cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 9, S("a123456789cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 10, S("a1234567890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 0, 11, S("a1234567890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 1, S("a2cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 4, S("a2345cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 8, S("a23456789cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 9, S("a234567890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 1, 10, S("a234567890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 1, S("a6cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 2, S("a67cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 4, S("a6789cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 5, S("a67890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 5, 6, S("a67890cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 9, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 9, 1, S("a0cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 9, 2, S("a0cde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 10, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 10, 1, S("acde"));
+    test(S("abcde"), 1, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 1, S("a1cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 10, S("a1234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 1, S("a2cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 9, S("a234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789cde"));
+}
+
+template <class S, class SV>
+void test8()
+{
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 1, S("a1cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 5, S("a12345cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 9, S("a123456789cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 10, S("a1234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 10, 11, S("a1234567890cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 19, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 19, 1, S("a0cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 19, 2, S("a0cde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 20, 0, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 20, 1, S("acde"));
+    test(S("abcde"), 1, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 2, SV(""), 0, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV(""), 0, 1, S("ade"));
+    test(S("abcde"), 1, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 1, S("a1de"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 2, S("a12de"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 4, S("a1234de"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 5, S("a12345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 0, 6, S("a12345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 1, S("a2de"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 2, S("a23de"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 3, S("a234de"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 4, S("a2345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 1, 5, S("a2345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 2, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 2, 1, S("a3de"));
+    test(S("abcde"), 1, 2, SV("12345"), 2, 2, S("a34de"));
+    test(S("abcde"), 1, 2, SV("12345"), 2, 3, S("a345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 2, 4, S("a345de"));
+    test(S("abcde"), 1, 2, SV("12345"), 4, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 4, 1, S("a5de"));
+    test(S("abcde"), 1, 2, SV("12345"), 4, 2, S("a5de"));
+    test(S("abcde"), 1, 2, SV("12345"), 5, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 5, 1, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 1, S("a1de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 5, S("a12345de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 9, S("a123456789de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 10, S("a1234567890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 0, 11, S("a1234567890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 1, S("a2de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 4, S("a2345de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 8, S("a23456789de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 9, S("a234567890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 1, 10, S("a234567890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 1, S("a6de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 2, S("a67de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 4, S("a6789de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 5, S("a67890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 5, 6, S("a67890de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 9, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 9, 1, S("a0de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 9, 2, S("a0de"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 10, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 10, 1, S("ade"));
+    test(S("abcde"), 1, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 1, S("a1de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 10, S("a1234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 19, S("a1234567890123456789de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 20, S("a12345678901234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 0, 21, S("a12345678901234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 1, S("a2de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 9, S("a234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 18, S("a234567890123456789de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 19, S("a2345678901234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 1, 20, S("a2345678901234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 1, S("a1de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 5, S("a12345de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 9, S("a123456789de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 10, S("a1234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 10, 11, S("a1234567890de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 19, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 19, 1, S("a0de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 19, 2, S("a0de"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 20, 0, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 20, 1, S("ade"));
+    test(S("abcde"), 1, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 3, SV(""), 0, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV(""), 0, 1, S("ae"));
+    test(S("abcde"), 1, 3, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 1, S("a1e"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 2, S("a12e"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 4, S("a1234e"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 5, S("a12345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 0, 6, S("a12345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 1, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 1, 1, S("a2e"));
+    test(S("abcde"), 1, 3, SV("12345"), 1, 2, S("a23e"));
+}
+
+template <class S, class SV>
+void test9()
+{
+    test(S("abcde"), 1, 3, SV("12345"), 1, 3, S("a234e"));
+    test(S("abcde"), 1, 3, SV("12345"), 1, 4, S("a2345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 1, 5, S("a2345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 2, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 2, 1, S("a3e"));
+    test(S("abcde"), 1, 3, SV("12345"), 2, 2, S("a34e"));
+    test(S("abcde"), 1, 3, SV("12345"), 2, 3, S("a345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 2, 4, S("a345e"));
+    test(S("abcde"), 1, 3, SV("12345"), 4, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 4, 1, S("a5e"));
+    test(S("abcde"), 1, 3, SV("12345"), 4, 2, S("a5e"));
+    test(S("abcde"), 1, 3, SV("12345"), 5, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 5, 1, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 1, S("a1e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 5, S("a12345e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 9, S("a123456789e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 10, S("a1234567890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 0, 11, S("a1234567890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 1, S("a2e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 4, S("a2345e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 8, S("a23456789e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 9, S("a234567890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 1, 10, S("a234567890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 1, S("a6e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 2, S("a67e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 4, S("a6789e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 5, S("a67890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 5, 6, S("a67890e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 9, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 9, 1, S("a0e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 9, 2, S("a0e"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 10, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 10, 1, S("ae"));
+    test(S("abcde"), 1, 3, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 1, S("a1e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 10, S("a1234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 19, S("a1234567890123456789e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 20, S("a12345678901234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 0, 21, S("a12345678901234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 1, S("a2e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 9, S("a234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 18, S("a234567890123456789e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 19, S("a2345678901234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 1, 20, S("a2345678901234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 1, S("a1e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 5, S("a12345e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 9, S("a123456789e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 10, S("a1234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 10, 11, S("a1234567890e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 19, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 19, 1, S("a0e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 19, 2, S("a0e"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 20, 0, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 20, 1, S("ae"));
+    test(S("abcde"), 1, 3, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 4, SV(""), 0, 0, S("a"));
+    test(S("abcde"), 1, 4, SV(""), 0, 1, S("a"));
+    test(S("abcde"), 1, 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 2, S("a12"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcde"), 1, 4, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 2, S("a23"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 3, S("a234"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcde"), 1, 4, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcde"), 1, 4, SV("12345"), 2, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 2, 1, S("a3"));
+    test(S("abcde"), 1, 4, SV("12345"), 2, 2, S("a34"));
+    test(S("abcde"), 1, 4, SV("12345"), 2, 3, S("a345"));
+    test(S("abcde"), 1, 4, SV("12345"), 2, 4, S("a345"));
+    test(S("abcde"), 1, 4, SV("12345"), 4, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 4, 1, S("a5"));
+    test(S("abcde"), 1, 4, SV("12345"), 4, 2, S("a5"));
+    test(S("abcde"), 1, 4, SV("12345"), 5, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 5, 1, S("a"));
+    test(S("abcde"), 1, 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 8, S("a23456789"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 1, 10, S("a234567890"));
+}
+
+template <class S, class SV>
+void test10()
+{
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcde"), 1, 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 1, S("a1"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcde"), 1, 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, 5, SV(""), 0, 0, S("a"));
+    test(S("abcde"), 1, 5, SV(""), 0, 1, S("a"));
+    test(S("abcde"), 1, 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 2, S("a12"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcde"), 1, 5, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 2, S("a23"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 3, S("a234"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcde"), 1, 5, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcde"), 1, 5, SV("12345"), 2, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 2, 1, S("a3"));
+    test(S("abcde"), 1, 5, SV("12345"), 2, 2, S("a34"));
+    test(S("abcde"), 1, 5, SV("12345"), 2, 3, S("a345"));
+    test(S("abcde"), 1, 5, SV("12345"), 2, 4, S("a345"));
+    test(S("abcde"), 1, 5, SV("12345"), 4, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 4, 1, S("a5"));
+    test(S("abcde"), 1, 5, SV("12345"), 4, 2, S("a5"));
+    test(S("abcde"), 1, 5, SV("12345"), 5, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 5, 1, S("a"));
+    test(S("abcde"), 1, 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 8, S("a23456789"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 1, 10, S("a234567890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcde"), 1, 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 1, S("a1"));
+}
+
+template <class S, class SV>
+void test11()
+{
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcde"), 1, 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 2, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 2, S("ab12cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 4, S("ab1234cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 0, 6, S("ab12345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 2, S("ab23cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 3, S("ab234cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 1, 5, S("ab2345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 2, 1, S("ab3cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 2, 2, S("ab34cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 2, 3, S("ab345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 2, 4, S("ab345cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 4, 1, S("ab5cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 4, 2, S("ab5cde"));
+    test(S("abcde"), 2, 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 0, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 8, S("ab23456789cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 1, 10, S("ab234567890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 1, S("ab6cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 2, S("ab67cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 4, S("ab6789cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 5, S("ab67890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 5, 6, S("ab67890cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 9, 1, S("ab0cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 9, 2, S("ab0cde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 2, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 18, S("ab234567890123456789cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 1, S("ab1cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 5, S("ab12345cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 10, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 19, 1, S("ab0cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 19, 2, S("ab0cde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 2, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, 1, SV(""), 0, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV(""), 0, 1, S("abde"));
+    test(S("abcde"), 2, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 1, S("ab1de"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 2, S("ab12de"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 4, S("ab1234de"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 5, S("ab12345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 0, 6, S("ab12345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 1, S("ab2de"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 2, S("ab23de"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 3, S("ab234de"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 4, S("ab2345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 1, 5, S("ab2345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 2, 0, S("abde"));
+}
+
+template <class S, class SV>
+void test12()
+{
+    test(S("abcde"), 2, 1, SV("12345"), 2, 1, S("ab3de"));
+    test(S("abcde"), 2, 1, SV("12345"), 2, 2, S("ab34de"));
+    test(S("abcde"), 2, 1, SV("12345"), 2, 3, S("ab345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 2, 4, S("ab345de"));
+    test(S("abcde"), 2, 1, SV("12345"), 4, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345"), 4, 1, S("ab5de"));
+    test(S("abcde"), 2, 1, SV("12345"), 4, 2, S("ab5de"));
+    test(S("abcde"), 2, 1, SV("12345"), 5, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345"), 5, 1, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 1, S("ab1de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 5, S("ab12345de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 9, S("ab123456789de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 10, S("ab1234567890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 0, 11, S("ab1234567890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 1, S("ab2de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 4, S("ab2345de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 8, S("ab23456789de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 9, S("ab234567890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 1, 10, S("ab234567890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 1, S("ab6de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 2, S("ab67de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 4, S("ab6789de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 5, S("ab67890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 5, 6, S("ab67890de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 9, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 9, 1, S("ab0de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 9, 2, S("ab0de"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 10, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 10, 1, S("abde"));
+    test(S("abcde"), 2, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 1, S("ab1de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 10, S("ab1234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 1, S("ab2de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 9, S("ab234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 18, S("ab234567890123456789de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 1, S("ab1de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 5, S("ab12345de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 9, S("ab123456789de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 10, S("ab1234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 10, 11, S("ab1234567890de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 19, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 19, 1, S("ab0de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 19, 2, S("ab0de"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 20, 0, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 20, 1, S("abde"));
+    test(S("abcde"), 2, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, 2, SV(""), 0, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV(""), 0, 1, S("abe"));
+    test(S("abcde"), 2, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 1, S("ab1e"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 2, S("ab12e"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 4, S("ab1234e"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 5, S("ab12345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 0, 6, S("ab12345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 1, S("ab2e"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 2, S("ab23e"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 3, S("ab234e"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 4, S("ab2345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 1, 5, S("ab2345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 2, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 2, 1, S("ab3e"));
+    test(S("abcde"), 2, 2, SV("12345"), 2, 2, S("ab34e"));
+    test(S("abcde"), 2, 2, SV("12345"), 2, 3, S("ab345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 2, 4, S("ab345e"));
+    test(S("abcde"), 2, 2, SV("12345"), 4, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 4, 1, S("ab5e"));
+    test(S("abcde"), 2, 2, SV("12345"), 4, 2, S("ab5e"));
+    test(S("abcde"), 2, 2, SV("12345"), 5, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 5, 1, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 1, S("ab1e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 5, S("ab12345e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 9, S("ab123456789e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 10, S("ab1234567890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 0, 11, S("ab1234567890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 1, S("ab2e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 4, S("ab2345e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 8, S("ab23456789e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 9, S("ab234567890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 1, 10, S("ab234567890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 1, S("ab6e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 2, S("ab67e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 4, S("ab6789e"));
+}
+
+template <class S, class SV>
+void test13()
+{
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 5, S("ab67890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 5, 6, S("ab67890e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 9, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 9, 1, S("ab0e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 9, 2, S("ab0e"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 10, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 10, 1, S("abe"));
+    test(S("abcde"), 2, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 1, S("ab1e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 10, S("ab1234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 1, S("ab2e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 9, S("ab234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 18, S("ab234567890123456789e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 1, S("ab1e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 5, S("ab12345e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 9, S("ab123456789e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 10, S("ab1234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 10, 11, S("ab1234567890e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 19, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 19, 1, S("ab0e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 19, 2, S("ab0e"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 20, 0, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 20, 1, S("abe"));
+    test(S("abcde"), 2, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, 3, SV(""), 0, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV(""), 0, 1, S("ab"));
+    test(S("abcde"), 2, 3, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 2, S("ab12"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 4, S("ab1234"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 5, S("ab12345"));
+    test(S("abcde"), 2, 3, SV("12345"), 0, 6, S("ab12345"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 2, S("ab23"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 3, S("ab234"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 4, S("ab2345"));
+    test(S("abcde"), 2, 3, SV("12345"), 1, 5, S("ab2345"));
+    test(S("abcde"), 2, 3, SV("12345"), 2, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 2, 1, S("ab3"));
+    test(S("abcde"), 2, 3, SV("12345"), 2, 2, S("ab34"));
+    test(S("abcde"), 2, 3, SV("12345"), 2, 3, S("ab345"));
+    test(S("abcde"), 2, 3, SV("12345"), 2, 4, S("ab345"));
+    test(S("abcde"), 2, 3, SV("12345"), 4, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 4, 1, S("ab5"));
+    test(S("abcde"), 2, 3, SV("12345"), 4, 2, S("ab5"));
+    test(S("abcde"), 2, 3, SV("12345"), 5, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 5, 1, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 5, S("ab12345"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 9, S("ab123456789"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 0, 11, S("ab1234567890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 4, S("ab2345"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 8, S("ab23456789"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 9, S("ab234567890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 1, 10, S("ab234567890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 1, S("ab6"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 2, S("ab67"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 4, S("ab6789"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 5, S("ab67890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 5, 6, S("ab67890"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 9, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 9, 1, S("ab0"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 9, 2, S("ab0"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 10, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 10, 1, S("ab"));
+    test(S("abcde"), 2, 3, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 9, S("ab234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 18, S("ab234567890123456789"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 1, S("ab1"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 5, S("ab12345"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 9, S("ab123456789"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 10, 11, S("ab1234567890"));
+}
+
+template <class S, class SV>
+void test14()
+{
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 19, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 19, 1, S("ab0"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 19, 2, S("ab0"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 20, 0, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 20, 1, S("ab"));
+    test(S("abcde"), 2, 3, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, 4, SV(""), 0, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV(""), 0, 1, S("ab"));
+    test(S("abcde"), 2, 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 2, S("ab12"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 4, S("ab1234"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 5, S("ab12345"));
+    test(S("abcde"), 2, 4, SV("12345"), 0, 6, S("ab12345"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 2, S("ab23"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 3, S("ab234"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 4, S("ab2345"));
+    test(S("abcde"), 2, 4, SV("12345"), 1, 5, S("ab2345"));
+    test(S("abcde"), 2, 4, SV("12345"), 2, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 2, 1, S("ab3"));
+    test(S("abcde"), 2, 4, SV("12345"), 2, 2, S("ab34"));
+    test(S("abcde"), 2, 4, SV("12345"), 2, 3, S("ab345"));
+    test(S("abcde"), 2, 4, SV("12345"), 2, 4, S("ab345"));
+    test(S("abcde"), 2, 4, SV("12345"), 4, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 4, 1, S("ab5"));
+    test(S("abcde"), 2, 4, SV("12345"), 4, 2, S("ab5"));
+    test(S("abcde"), 2, 4, SV("12345"), 5, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 5, 1, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 5, S("ab12345"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 9, S("ab123456789"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 0, 11, S("ab1234567890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 4, S("ab2345"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 8, S("ab23456789"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 9, S("ab234567890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 1, 10, S("ab234567890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 1, S("ab6"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 2, S("ab67"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 4, S("ab6789"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 5, S("ab67890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 5, 6, S("ab67890"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 9, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 9, 1, S("ab0"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 9, 2, S("ab0"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 10, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 10, 1, S("ab"));
+    test(S("abcde"), 2, 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 1, S("ab1"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 19, S("ab1234567890123456789"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 20, S("ab12345678901234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 0, 21, S("ab12345678901234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 1, S("ab2"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 9, S("ab234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 18, S("ab234567890123456789"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 19, S("ab2345678901234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 1, 20, S("ab2345678901234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 1, S("ab1"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 5, S("ab12345"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 9, S("ab123456789"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 10, S("ab1234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 10, 11, S("ab1234567890"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 19, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 19, 1, S("ab0"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 19, 2, S("ab0"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 20, 0, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 20, 1, S("ab"));
+    test(S("abcde"), 2, 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 4, 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 4, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 2, S("abcd12e"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 4, S("abcd1234e"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, 0, SV("12345"), 0, 6, S("abcd12345e"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 2, S("abcd23e"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 3, S("abcd234e"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, 0, SV("12345"), 1, 5, S("abcd2345e"));
+    test(S("abcde"), 4, 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 2, 1, S("abcd3e"));
+    test(S("abcde"), 4, 0, SV("12345"), 2, 2, S("abcd34e"));
+    test(S("abcde"), 4, 0, SV("12345"), 2, 3, S("abcd345e"));
+    test(S("abcde"), 4, 0, SV("12345"), 2, 4, S("abcd345e"));
+}
+
+template <class S, class SV>
+void test15()
+{
+    test(S("abcde"), 4, 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 4, 1, S("abcd5e"));
+    test(S("abcde"), 4, 0, SV("12345"), 4, 2, S("abcd5e"));
+    test(S("abcde"), 4, 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 9, S("abcd123456789e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 0, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 8, S("abcd23456789e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 1, 10, S("abcd234567890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 1, S("abcd6e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 2, S("abcd67e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 4, S("abcd6789e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 5, S("abcd67890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 5, 6, S("abcd67890e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 9, 1, S("abcd0e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 9, 2, S("abcd0e"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 4, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 19, S("abcd1234567890123456789e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 20, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 0, 21, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 18, S("abcd234567890123456789e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 19, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 1, 20, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 1, S("abcd1e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 5, S("abcd12345e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 9, S("abcd123456789e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 10, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 19, 1, S("abcd0e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 19, 2, S("abcd0e"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 4, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 4, 1, SV(""), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV(""), 0, 1, S("abcd"));
+    test(S("abcde"), 4, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 2, S("abcd12"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 4, S("abcd1234"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 5, S("abcd12345"));
+    test(S("abcde"), 4, 1, SV("12345"), 0, 6, S("abcd12345"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 2, S("abcd23"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 3, S("abcd234"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 4, S("abcd2345"));
+    test(S("abcde"), 4, 1, SV("12345"), 1, 5, S("abcd2345"));
+    test(S("abcde"), 4, 1, SV("12345"), 2, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 2, 1, S("abcd3"));
+    test(S("abcde"), 4, 1, SV("12345"), 2, 2, S("abcd34"));
+    test(S("abcde"), 4, 1, SV("12345"), 2, 3, S("abcd345"));
+    test(S("abcde"), 4, 1, SV("12345"), 2, 4, S("abcd345"));
+    test(S("abcde"), 4, 1, SV("12345"), 4, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 4, 1, S("abcd5"));
+    test(S("abcde"), 4, 1, SV("12345"), 4, 2, S("abcd5"));
+    test(S("abcde"), 4, 1, SV("12345"), 5, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 5, 1, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 5, S("abcd12345"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 9, S("abcd123456789"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 0, 11, S("abcd1234567890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 4, S("abcd2345"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 8, S("abcd23456789"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 9, S("abcd234567890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 1, 10, S("abcd234567890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 1, S("abcd6"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 2, S("abcd67"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 4, S("abcd6789"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 5, S("abcd67890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 5, 6, S("abcd67890"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 9, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 9, 1, S("abcd0"));
+}
+
+template <class S, class SV>
+void test16()
+{
+    test(S("abcde"), 4, 1, SV("1234567890"), 9, 2, S("abcd0"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 10, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 10, 1, S("abcd"));
+    test(S("abcde"), 4, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 19, S("abcd1234567890123456789"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 20, S("abcd12345678901234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 0, 21, S("abcd12345678901234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 9, S("abcd234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 18, S("abcd234567890123456789"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 19, S("abcd2345678901234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 1, 20, S("abcd2345678901234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 1, S("abcd1"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 5, S("abcd12345"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 9, S("abcd123456789"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 10, 11, S("abcd1234567890"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 19, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 19, 1, S("abcd0"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 19, 2, S("abcd0"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 20, 0, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 20, 1, S("abcd"));
+    test(S("abcde"), 4, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 4, 2, SV(""), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV(""), 0, 1, S("abcd"));
+    test(S("abcde"), 4, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 2, S("abcd12"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 4, S("abcd1234"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 5, S("abcd12345"));
+    test(S("abcde"), 4, 2, SV("12345"), 0, 6, S("abcd12345"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 2, S("abcd23"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 3, S("abcd234"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 4, S("abcd2345"));
+    test(S("abcde"), 4, 2, SV("12345"), 1, 5, S("abcd2345"));
+    test(S("abcde"), 4, 2, SV("12345"), 2, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 2, 1, S("abcd3"));
+    test(S("abcde"), 4, 2, SV("12345"), 2, 2, S("abcd34"));
+    test(S("abcde"), 4, 2, SV("12345"), 2, 3, S("abcd345"));
+    test(S("abcde"), 4, 2, SV("12345"), 2, 4, S("abcd345"));
+    test(S("abcde"), 4, 2, SV("12345"), 4, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 4, 1, S("abcd5"));
+    test(S("abcde"), 4, 2, SV("12345"), 4, 2, S("abcd5"));
+    test(S("abcde"), 4, 2, SV("12345"), 5, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 5, 1, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 5, S("abcd12345"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 9, S("abcd123456789"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 0, 11, S("abcd1234567890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 4, S("abcd2345"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 8, S("abcd23456789"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 9, S("abcd234567890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 1, 10, S("abcd234567890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 1, S("abcd6"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 2, S("abcd67"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 4, S("abcd6789"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 5, S("abcd67890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 5, 6, S("abcd67890"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 9, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 9, 1, S("abcd0"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 9, 2, S("abcd0"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 10, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 10, 1, S("abcd"));
+    test(S("abcde"), 4, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 1, S("abcd1"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 19, S("abcd1234567890123456789"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 20, S("abcd12345678901234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 0, 21, S("abcd12345678901234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 1, S("abcd2"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 9, S("abcd234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 18, S("abcd234567890123456789"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 19, S("abcd2345678901234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 1, 20, S("abcd2345678901234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 1, S("abcd1"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 5, S("abcd12345"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 9, S("abcd123456789"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 10, S("abcd1234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 10, 11, S("abcd1234567890"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 19, 0, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 19, 1, S("abcd0"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 19, 2, S("abcd0"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 20, 0, S("abcd"));
+}
+
+template <class S, class SV>
+void test17()
+{
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 20, 1, S("abcd"));
+    test(S("abcde"), 4, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 5, 0, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 5, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 2, S("abcde12"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 4, S("abcde1234"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, 0, SV("12345"), 0, 6, S("abcde12345"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 2, S("abcde23"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 3, S("abcde234"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, 0, SV("12345"), 1, 5, S("abcde2345"));
+    test(S("abcde"), 5, 0, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 2, 1, S("abcde3"));
+    test(S("abcde"), 5, 0, SV("12345"), 2, 2, S("abcde34"));
+    test(S("abcde"), 5, 0, SV("12345"), 2, 3, S("abcde345"));
+    test(S("abcde"), 5, 0, SV("12345"), 2, 4, S("abcde345"));
+    test(S("abcde"), 5, 0, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 4, 1, S("abcde5"));
+    test(S("abcde"), 5, 0, SV("12345"), 4, 2, S("abcde5"));
+    test(S("abcde"), 5, 0, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 5, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 5, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 5, 1, SV(""), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV(""), 0, 1, S("abcde"));
+    test(S("abcde"), 5, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 2, S("abcde12"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 4, S("abcde1234"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, 1, SV("12345"), 0, 6, S("abcde12345"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 2, S("abcde23"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 3, S("abcde234"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, 1, SV("12345"), 1, 5, S("abcde2345"));
+    test(S("abcde"), 5, 1, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345"), 2, 1, S("abcde3"));
+    test(S("abcde"), 5, 1, SV("12345"), 2, 2, S("abcde34"));
+    test(S("abcde"), 5, 1, SV("12345"), 2, 3, S("abcde345"));
+    test(S("abcde"), 5, 1, SV("12345"), 2, 4, S("abcde345"));
+    test(S("abcde"), 5, 1, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345"), 4, 1, S("abcde5"));
+    test(S("abcde"), 5, 1, SV("12345"), 4, 2, S("abcde5"));
+    test(S("abcde"), 5, 1, SV("12345"), 5, 0, S("abcde"));
+}
+
+template <class S, class SV>
+void test18()
+{
+    test(S("abcde"), 5, 1, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 5, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 5, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV(""), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV(""), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("1234567890"), 11, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test19()
+{
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcde"), 6, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 2, S("12abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 4, S("1234abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 0, 6, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 2, S("23abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 3, S("234abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 1, 5, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 2, 1, S("3abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 2, 2, S("34abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 2, 3, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 2, 4, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 4, 1, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 4, 2, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 0, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 8, S("23456789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 1, 10, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 1, S("6abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 2, S("67abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 4, S("6789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 5, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 5, 6, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 9, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 9, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 10, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 19, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 19, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 1, SV(""), 0, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV(""), 0, 1, S("bcdefghij"));
+}
+
+template <class S, class SV>
+void test20()
+{
+    test(S("abcdefghij"), 0, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 1, S("1bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 2, S("12bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 4, S("1234bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 5, S("12345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 0, 6, S("12345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 1, S("2bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 2, S("23bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 3, S("234bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 4, S("2345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 1, 5, S("2345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 2, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 2, 1, S("3bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 2, 2, S("34bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 2, 3, S("345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 2, 4, S("345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 4, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 4, 1, S("5bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 4, 2, S("5bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 5, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 5, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 1, S("1bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 5, S("12345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 9, S("123456789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 10, S("1234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 0, 11, S("1234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 1, S("2bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 4, S("2345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 8, S("23456789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 9, S("234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 1, 10, S("234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 1, S("6bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 2, S("67bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 4, S("6789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 5, S("67890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 5, 6, S("67890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 9, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 9, 1, S("0bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 9, 2, S("0bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 10, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 10, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 1, S("1bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 10, S("1234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 19, S("1234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 20, S("12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 0, 21, S("12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 1, S("2bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 9, S("234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 18, S("234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 19, S("2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 1, 20, S("2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 1, S("1bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 5, S("12345bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 9, S("123456789bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 10, S("1234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 10, 11, S("1234567890bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 19, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 19, 1, S("0bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 19, 2, S("0bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 20, 0, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 20, 1, S("bcdefghij"));
+    test(S("abcdefghij"), 0, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 5, SV(""), 0, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV(""), 0, 1, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 1, S("1fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 2, S("12fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 4, S("1234fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 5, S("12345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 0, 6, S("12345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 1, S("2fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 2, S("23fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 3, S("234fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 4, S("2345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 1, 5, S("2345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 2, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 2, 1, S("3fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 2, 2, S("34fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 2, 3, S("345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 2, 4, S("345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 4, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 4, 1, S("5fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 4, 2, S("5fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 5, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 5, 1, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 1, S("1fghij"));
+}
+
+template <class S, class SV>
+void test21()
+{
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 5, S("12345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 9, S("123456789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 10, S("1234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 0, 11, S("1234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 1, S("2fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 4, S("2345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 8, S("23456789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 9, S("234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 1, 10, S("234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 1, S("6fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 2, S("67fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 4, S("6789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 5, S("67890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 5, 6, S("67890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 9, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 9, 1, S("0fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 9, 2, S("0fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 10, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 10, 1, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 1, S("1fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 10, S("1234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 19, S("1234567890123456789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 20, S("12345678901234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 0, 21, S("12345678901234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 1, S("2fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 9, S("234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 18, S("234567890123456789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 19, S("2345678901234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 1, 20, S("2345678901234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 1, S("1fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 5, S("12345fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 9, S("123456789fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 10, S("1234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 10, 11, S("1234567890fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 19, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 19, 1, S("0fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 19, 2, S("0fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 20, 0, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 20, 1, S("fghij"));
+    test(S("abcdefghij"), 0, 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 9, SV(""), 0, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV(""), 0, 1, S("j"));
+    test(S("abcdefghij"), 0, 9, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 1, S("1j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 2, S("12j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 4, S("1234j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 5, S("12345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 0, 6, S("12345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 1, S("2j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 2, S("23j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 3, S("234j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 4, S("2345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 1, 5, S("2345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 2, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 2, 1, S("3j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 2, 2, S("34j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 2, 3, S("345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 2, 4, S("345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 4, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 4, 1, S("5j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 4, 2, S("5j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 5, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 5, 1, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 1, S("1j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 5, S("12345j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 9, S("123456789j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 10, S("1234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 0, 11, S("1234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 1, S("2j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 4, S("2345j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 8, S("23456789j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 9, S("234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 1, 10, S("234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 1, S("6j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 2, S("67j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 4, S("6789j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 5, S("67890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 5, 6, S("67890j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 9, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 9, 1, S("0j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 9, 2, S("0j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 10, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 10, 1, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 1, S("1j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 10, S("1234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 19, S("1234567890123456789j"));
+}
+
+template <class S, class SV>
+void test22()
+{
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 20, S("12345678901234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 0, 21, S("12345678901234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 1, S("2j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 9, S("234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 18, S("234567890123456789j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 19, S("2345678901234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 1, 20, S("2345678901234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 1, S("1j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 5, S("12345j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 9, S("123456789j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 10, S("1234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 10, 11, S("1234567890j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 19, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 19, 1, S("0j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 19, 2, S("0j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 20, 0, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 20, 1, S("j"));
+    test(S("abcdefghij"), 0, 9, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 10, SV(""), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV(""), 0, 1, S(""));
+    test(S("abcdefghij"), 0, 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 2, S("12"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 4, S("1234"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 5, S("12345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 0, 6, S("12345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 2, S("23"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 3, S("234"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 4, S("2345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 1, 5, S("2345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 2, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 2, 1, S("3"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 2, 2, S("34"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 2, 3, S("345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 2, 4, S("345"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 4, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 4, 1, S("5"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 4, 2, S("5"));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 5, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 5, 1, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 9, S("123456789"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 9, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 10, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 10, 1, S(""));
+    test(S("abcdefghij"), 0, 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcdefghij"), 0, 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 11, SV(""), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV(""), 0, 1, S(""));
+    test(S("abcdefghij"), 0, 11, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 2, S("12"));
+}
+
+template <class S, class SV>
+void test23()
+{
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 4, S("1234"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 5, S("12345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 0, 6, S("12345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 2, S("23"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 3, S("234"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 4, S("2345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 1, 5, S("2345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 2, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 2, 1, S("3"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 2, 2, S("34"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 2, 3, S("345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 2, 4, S("345"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 4, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 4, 1, S("5"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 4, 2, S("5"));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 5, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 5, 1, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 9, S("123456789"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 9, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 10, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 10, 1, S(""));
+    test(S("abcdefghij"), 0, 11, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcdefghij"), 0, 11, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 2, S("a12bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 4, S("a1234bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 0, 6, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 2, S("a23bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 3, S("a234bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 1, 5, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 2, 1, S("a3bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 2, 2, S("a34bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 2, 3, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 2, 4, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 4, 1, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 4, 2, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 0, 11, S("a1234567890bcdefghij"));
+}
+
+template <class S, class SV>
+void test24()
+{
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 8, S("a23456789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 1, 10, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 1, S("a6bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 2, S("a67bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 4, S("a6789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 5, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 5, 6, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 9, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 9, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 10, 11, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 19, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 19, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 1, SV(""), 0, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV(""), 0, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 1, S("a1cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 2, S("a12cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 4, S("a1234cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 5, S("a12345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 0, 6, S("a12345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 1, S("a2cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 2, S("a23cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 3, S("a234cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 4, S("a2345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 1, 5, S("a2345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 2, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 2, 1, S("a3cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 2, 2, S("a34cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 2, 3, S("a345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 2, 4, S("a345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 4, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 4, 1, S("a5cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 4, 2, S("a5cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 5, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 5, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 1, S("a1cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 5, S("a12345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 9, S("a123456789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 10, S("a1234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 0, 11, S("a1234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 1, S("a2cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 4, S("a2345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 8, S("a23456789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 9, S("a234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 1, 10, S("a234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 1, S("a6cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 2, S("a67cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 4, S("a6789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 5, S("a67890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 5, 6, S("a67890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 9, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 9, 1, S("a0cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 9, 2, S("a0cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 10, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 10, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 1, S("a1cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 10, S("a1234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 1, S("a2cdefghij"));
+}
+
+template <class S, class SV>
+void test25()
+{
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 9, S("a234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 1, S("a1cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 5, S("a12345cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 9, S("a123456789cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 10, S("a1234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 10, 11, S("a1234567890cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 19, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 19, 1, S("a0cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 19, 2, S("a0cdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 20, 0, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 20, 1, S("acdefghij"));
+    test(S("abcdefghij"), 1, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 4, SV(""), 0, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV(""), 0, 1, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 1, S("a1fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 2, S("a12fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 4, S("a1234fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 5, S("a12345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 0, 6, S("a12345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 1, S("a2fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 2, S("a23fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 3, S("a234fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 4, S("a2345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 1, 5, S("a2345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 2, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 2, 1, S("a3fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 2, 2, S("a34fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 2, 3, S("a345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 2, 4, S("a345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 4, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 4, 1, S("a5fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 4, 2, S("a5fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 5, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 5, 1, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 1, S("a1fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 5, S("a12345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 9, S("a123456789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 10, S("a1234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 0, 11, S("a1234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 1, S("a2fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 4, S("a2345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 8, S("a23456789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 9, S("a234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 1, 10, S("a234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 1, S("a6fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 2, S("a67fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 4, S("a6789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 5, S("a67890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 5, 6, S("a67890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 9, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 9, 1, S("a0fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 9, 2, S("a0fghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 10, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 10, 1, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 1, S("a1fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 10, S("a1234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 19, S("a1234567890123456789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 20, S("a12345678901234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 0, 21, S("a12345678901234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 1, S("a2fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 9, S("a234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 18, S("a234567890123456789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 19, S("a2345678901234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 1, 20, S("a2345678901234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 1, S("a1fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 5, S("a12345fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 9, S("a123456789fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 10, S("a1234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 10, 11, S("a1234567890fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 19, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 19, 1, S("a0fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 19, 2, S("a0fghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 20, 0, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 20, 1, S("afghij"));
+    test(S("abcdefghij"), 1, 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 8, SV(""), 0, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV(""), 0, 1, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 1, S("a1j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 2, S("a12j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 4, S("a1234j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 5, S("a12345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 0, 6, S("a12345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 0, S("aj"));
+}
+
+template <class S, class SV>
+void test26()
+{
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 1, S("a2j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 2, S("a23j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 3, S("a234j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 4, S("a2345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 1, 5, S("a2345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 2, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 2, 1, S("a3j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 2, 2, S("a34j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 2, 3, S("a345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 2, 4, S("a345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 4, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 4, 1, S("a5j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 4, 2, S("a5j"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 5, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 5, 1, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 1, S("a1j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 5, S("a12345j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 9, S("a123456789j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 10, S("a1234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 0, 11, S("a1234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 1, S("a2j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 4, S("a2345j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 8, S("a23456789j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 9, S("a234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 1, 10, S("a234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 1, S("a6j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 2, S("a67j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 4, S("a6789j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 5, S("a67890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 5, 6, S("a67890j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 9, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 9, 1, S("a0j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 9, 2, S("a0j"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 10, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 10, 1, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 1, S("a1j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 10, S("a1234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 19, S("a1234567890123456789j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 20, S("a12345678901234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 0, 21, S("a12345678901234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 1, S("a2j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 9, S("a234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 18, S("a234567890123456789j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 19, S("a2345678901234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 1, 20, S("a2345678901234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 1, S("a1j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 5, S("a12345j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 9, S("a123456789j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 10, S("a1234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 10, 11, S("a1234567890j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 19, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 19, 1, S("a0j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 19, 2, S("a0j"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 20, 0, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 20, 1, S("aj"));
+    test(S("abcdefghij"), 1, 8, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 9, SV(""), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV(""), 0, 1, S("a"));
+    test(S("abcdefghij"), 1, 9, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 2, S("a12"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 2, S("a23"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 3, S("a234"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 2, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 2, 1, S("a3"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 2, 2, S("a34"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 2, 3, S("a345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 2, 4, S("a345"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 4, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 4, 1, S("a5"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 4, 2, S("a5"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 5, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 5, 1, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 8, S("a23456789"));
+}
+
+template <class S, class SV>
+void test27()
+{
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 1, 10, S("a234567890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 1, S("a1"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcdefghij"), 1, 9, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 10, SV(""), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV(""), 0, 1, S("a"));
+    test(S("abcdefghij"), 1, 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 2, S("a12"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 2, S("a23"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 3, S("a234"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 2, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 2, 1, S("a3"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 2, 2, S("a34"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 2, 3, S("a345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 2, 4, S("a345"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 4, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 4, 1, S("a5"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 4, 2, S("a5"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 5, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 5, 1, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 8, S("a23456789"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 1, 10, S("a234567890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+}
+
+template <class S, class SV>
+void test28()
+{
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 1, S("a1"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcdefghij"), 1, 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 2, S("abcde12fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 4, S("abcde1234fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 0, 6, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 2, S("abcde23fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 3, S("abcde234fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 1, 5, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 2, 1, S("abcde3fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 2, 2, S("abcde34fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 2, 3, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 2, 4, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 4, 1, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 4, 2, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 0, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 8, S("abcde23456789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 1, 10, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 1, S("abcde6fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 2, S("abcde67fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 4, S("abcde6789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 5, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 5, 6, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 9, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 9, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 10, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 19, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 19, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 1, SV(""), 0, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV(""), 0, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 1, S("abcde1ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 2, S("abcde12ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 4, S("abcde1234ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 5, S("abcde12345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 0, 6, S("abcde12345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 1, S("abcde2ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 2, S("abcde23ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 3, S("abcde234ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 4, S("abcde2345ghij"));
+}
+
+template <class S, class SV>
+void test29()
+{
+    test(S("abcdefghij"), 5, 1, SV("12345"), 1, 5, S("abcde2345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 2, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 2, 1, S("abcde3ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 2, 2, S("abcde34ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 2, 3, S("abcde345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 2, 4, S("abcde345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 4, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 4, 1, S("abcde5ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 4, 2, S("abcde5ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 5, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 5, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 1, S("abcde1ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 5, S("abcde12345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 9, S("abcde123456789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 10, S("abcde1234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 0, 11, S("abcde1234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 1, S("abcde2ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 4, S("abcde2345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 8, S("abcde23456789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 9, S("abcde234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 1, 10, S("abcde234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 1, S("abcde6ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 2, S("abcde67ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 4, S("abcde6789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 5, S("abcde67890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 5, 6, S("abcde67890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 9, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 9, 1, S("abcde0ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 9, 2, S("abcde0ghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 10, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 10, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 1, S("abcde1ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 10, S("abcde1234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 1, S("abcde2ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 9, S("abcde234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 1, S("abcde1ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 5, S("abcde12345ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 9, S("abcde123456789ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 10, S("abcde1234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 10, 11, S("abcde1234567890ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 19, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 19, 1, S("abcde0ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 19, 2, S("abcde0ghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 20, 0, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 20, 1, S("abcdeghij"));
+    test(S("abcdefghij"), 5, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 2, SV(""), 0, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV(""), 0, 1, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 1, S("abcde1hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 2, S("abcde12hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 4, S("abcde1234hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 5, S("abcde12345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 0, 6, S("abcde12345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 1, S("abcde2hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 2, S("abcde23hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 3, S("abcde234hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 4, S("abcde2345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 1, 5, S("abcde2345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 2, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 2, 1, S("abcde3hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 2, 2, S("abcde34hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 2, 3, S("abcde345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 2, 4, S("abcde345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 4, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 4, 1, S("abcde5hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 4, 2, S("abcde5hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 5, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 5, 1, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 1, S("abcde1hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 5, S("abcde12345hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 9, S("abcde123456789hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 10, S("abcde1234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 0, 11, S("abcde1234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 1, S("abcde2hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 4, S("abcde2345hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 8, S("abcde23456789hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 9, S("abcde234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 1, 10, S("abcde234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 1, S("abcde6hij"));
+}
+
+template <class S, class SV>
+void test30()
+{
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 2, S("abcde67hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 4, S("abcde6789hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 5, S("abcde67890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 5, 6, S("abcde67890hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 9, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 9, 1, S("abcde0hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 9, 2, S("abcde0hij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 10, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 10, 1, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 1, S("abcde1hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 10, S("abcde1234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 1, S("abcde2hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 9, S("abcde234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 1, S("abcde1hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 5, S("abcde12345hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 9, S("abcde123456789hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 10, S("abcde1234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 10, 11, S("abcde1234567890hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 19, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 19, 1, S("abcde0hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 19, 2, S("abcde0hij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 20, 0, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 20, 1, S("abcdehij"));
+    test(S("abcdefghij"), 5, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 4, SV(""), 0, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV(""), 0, 1, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 1, S("abcde1j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 2, S("abcde12j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 4, S("abcde1234j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 5, S("abcde12345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 0, 6, S("abcde12345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 1, S("abcde2j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 2, S("abcde23j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 3, S("abcde234j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 4, S("abcde2345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 1, 5, S("abcde2345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 2, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 2, 1, S("abcde3j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 2, 2, S("abcde34j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 2, 3, S("abcde345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 2, 4, S("abcde345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 4, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 4, 1, S("abcde5j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 4, 2, S("abcde5j"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 5, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 5, 1, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 1, S("abcde1j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 5, S("abcde12345j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 9, S("abcde123456789j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 10, S("abcde1234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 0, 11, S("abcde1234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 1, S("abcde2j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 4, S("abcde2345j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 8, S("abcde23456789j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 9, S("abcde234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 1, 10, S("abcde234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 1, S("abcde6j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 2, S("abcde67j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 4, S("abcde6789j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 5, S("abcde67890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 5, 6, S("abcde67890j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 9, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 9, 1, S("abcde0j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 9, 2, S("abcde0j"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 10, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 10, 1, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 1, S("abcde1j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 10, S("abcde1234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 1, S("abcde2j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 9, S("abcde234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 1, S("abcde1j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 5, S("abcde12345j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 9, S("abcde123456789j"));
+}
+
+template <class S, class SV>
+void test31()
+{
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 10, S("abcde1234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 10, 11, S("abcde1234567890j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 19, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 19, 1, S("abcde0j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 19, 2, S("abcde0j"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 20, 0, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 20, 1, S("abcdej"));
+    test(S("abcdefghij"), 5, 4, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 5, SV(""), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV(""), 0, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 2, S("abcde12"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 4, S("abcde1234"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 0, 6, S("abcde12345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 2, S("abcde23"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 3, S("abcde234"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 4, S("abcde2345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 1, 5, S("abcde2345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 2, 1, S("abcde3"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 2, 2, S("abcde34"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 2, 3, S("abcde345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 2, 4, S("abcde345"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 4, 1, S("abcde5"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 4, 2, S("abcde5"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 6, SV(""), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV(""), 0, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 2, S("abcde12"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 4, S("abcde1234"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 0, 6, S("abcde12345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 2, S("abcde23"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 3, S("abcde234"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 4, S("abcde2345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 1, 5, S("abcde2345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 2, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 2, 1, S("abcde3"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 2, 2, S("abcde34"));
+}
+
+template <class S, class SV>
+void test32()
+{
+    test(S("abcdefghij"), 5, 6, SV("12345"), 2, 3, S("abcde345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 2, 4, S("abcde345"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 4, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 4, 1, S("abcde5"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 4, 2, S("abcde5"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 5, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 9, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 10, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 10, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcdefghij"), 5, 6, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 2, S("abcdefghi12j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 4, S("abcdefghi1234j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 0, 6, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 2, S("abcdefghi23j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 3, S("abcdefghi234j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 1, 5, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 2, 1, S("abcdefghi3j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 2, 2, S("abcdefghi34j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 2, 3, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 2, 4, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 4, 1, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 4, 2, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 0, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 8, S("abcdefghi23456789j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 1, 10, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 1, S("abcdefghi6j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 2, S("abcdefghi67j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 4, S("abcdefghi6789j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 5, S("abcdefghi67890j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 5, 6, S("abcdefghi67890j"));
+}
+
+template <class S, class SV>
+void test33()
+{
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 9, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 9, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 19, S("abcdefghi1234567890123456789j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 20, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 0, 21, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 18, S("abcdefghi234567890123456789j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 19, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 1, 20, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 10, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 19, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 19, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 1, SV(""), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV(""), 0, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 2, S("abcdefghi12"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 4, S("abcdefghi1234"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 0, 6, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 2, S("abcdefghi23"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 3, S("abcdefghi234"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 4, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 1, 5, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 2, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 2, 1, S("abcdefghi3"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 2, 2, S("abcdefghi34"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 2, 3, S("abcdefghi345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 2, 4, S("abcdefghi345"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 4, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 4, 1, S("abcdefghi5"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 4, 2, S("abcdefghi5"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 5, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 5, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 9, S("abcdefghi123456789"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 0, 11, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 4, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 8, S("abcdefghi23456789"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 9, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 1, 10, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 1, S("abcdefghi6"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 2, S("abcdefghi67"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 4, S("abcdefghi6789"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 5, S("abcdefghi67890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 5, 6, S("abcdefghi67890"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 9, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 9, 1, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 9, 2, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 10, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 10, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 19, S("abcdefghi1234567890123456789"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 20, S("abcdefghi12345678901234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 0, 21, S("abcdefghi12345678901234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 9, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 18, S("abcdefghi234567890123456789"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 19, S("abcdefghi2345678901234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 1, 20, S("abcdefghi2345678901234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 9, S("abcdefghi123456789"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, 11, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 19, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 19, 1, S("abcdefghi0"));
+}
+
+template <class S, class SV>
+void test34()
+{
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 19, 2, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 20, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 20, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 2, SV(""), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV(""), 0, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 2, S("abcdefghi12"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 4, S("abcdefghi1234"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 0, 6, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 2, S("abcdefghi23"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 3, S("abcdefghi234"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 4, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 1, 5, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 2, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 2, 1, S("abcdefghi3"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 2, 2, S("abcdefghi34"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 2, 3, S("abcdefghi345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 2, 4, S("abcdefghi345"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 4, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 4, 1, S("abcdefghi5"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 4, 2, S("abcdefghi5"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 5, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 5, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 9, S("abcdefghi123456789"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 0, 11, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 4, S("abcdefghi2345"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 8, S("abcdefghi23456789"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 9, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 1, 10, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 1, S("abcdefghi6"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 2, S("abcdefghi67"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 4, S("abcdefghi6789"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 5, S("abcdefghi67890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 5, 6, S("abcdefghi67890"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 9, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 9, 1, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 9, 2, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 10, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 10, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 19, S("abcdefghi1234567890123456789"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 20, S("abcdefghi12345678901234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 0, 21, S("abcdefghi12345678901234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 1, S("abcdefghi2"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 9, S("abcdefghi234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 18, S("abcdefghi234567890123456789"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 19, S("abcdefghi2345678901234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 1, 20, S("abcdefghi2345678901234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 1, S("abcdefghi1"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 5, S("abcdefghi12345"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 9, S("abcdefghi123456789"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 10, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 10, 11, S("abcdefghi1234567890"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 19, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 19, 1, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 19, 2, S("abcdefghi0"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 20, 0, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 20, 1, S("abcdefghi"));
+    test(S("abcdefghij"), 9, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 0, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 2, S("abcdefghij23"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 4, 1, S("abcdefghij5"));
+}
+
+template <class S, class SV>
+void test35()
+{
+    test(S("abcdefghij"), 10, 0, SV("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 4, S("abcdefghij6789"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 1, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 2, S("abcdefghij23"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 4, 1, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 4, S("abcdefghij6789"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 10, 0, S("abcdefghij"));
+}
+
+template <class S, class SV>
+void test36()
+{
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV(""), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV(""), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test37()
+{
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 2, S("12abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 4, S("1234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 0, 6, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 2, S("23abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 3, S("234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 4, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 1, 5, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 2, 1, S("3abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 2, 2, S("34abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 2, 3, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 2, 4, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 4, 1, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 4, 2, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 0, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 4, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 8, S("23456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 1, 10, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 1, S("6abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 2, S("67abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 4, S("6789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 5, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 5, 6, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 9, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 9, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 18, S("234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 10, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 19, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 19, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV(""), 0, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV(""), 0, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 1, S("1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 2, S("12bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 4, S("1234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 5, S("12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 0, 6, S("12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 1, S("2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 2, S("23bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 3, S("234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 4, S("2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 1, 5, S("2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 2, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 2, 1, S("3bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 2, 2, S("34bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 2, 3, S("345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 2, 4, S("345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 4, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 4, 1, S("5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 4, 2, S("5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 5, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 5, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345"), 6, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test38()
+{
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 1, S("1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 5, S("12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 9, S("123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 10, S("1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 0, 11, S("1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 1, S("2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 4, S("2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 8, S("23456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 9, S("234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 1, 10, S("234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 1, S("6bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 2, S("67bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 4, S("6789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 5, S("67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 5, 6, S("67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 9, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 9, 1, S("0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 9, 2, S("0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 10, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 10, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 1, S("1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 10, S("1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 19, S("1234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 20, S("12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 0, 21, S("12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 1, S("2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 9, S("234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 18, S("234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 19, S("2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 1, 20, S("2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 1, S("1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 5, S("12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 9, S("123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 10, S("1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 10, 11, S("1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 19, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 19, 1, S("0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 19, 2, S("0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 20, 0, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 20, 1, S("bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV(""), 0, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV(""), 0, 1, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 1, S("1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 2, S("12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 4, S("1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 5, S("12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 0, 6, S("12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 1, S("2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 2, S("23klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 3, S("234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 4, S("2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 1, 5, S("2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 2, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 2, 1, S("3klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 2, 2, S("34klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 2, 3, S("345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 2, 4, S("345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 4, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 4, 1, S("5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 4, 2, S("5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 5, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 5, 1, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 1, S("1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 5, S("12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 9, S("123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 10, S("1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 0, 11, S("1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 1, S("2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 4, S("2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 8, S("23456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 9, S("234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 1, 10, S("234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 1, S("6klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 2, S("67klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 4, S("6789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 5, S("67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 5, 6, S("67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 9, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 9, 1, S("0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 9, 2, S("0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 10, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 10, 1, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 1, S("1klmnopqrst"));
+}
+
+template <class S, class SV>
+void test39()
+{
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 10, S("1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 19, S("1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 20, S("12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 0, 21, S("12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 1, S("2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 9, S("234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 18, S("234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 19, S("2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 1, 20, S("2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 1, S("1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 5, S("12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 9, S("123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 10, S("1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 10, 11, S("1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 19, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 19, 1, S("0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 19, 2, S("0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 20, 0, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 20, 1, S("klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV(""), 0, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV(""), 0, 1, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 1, S("1t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 2, S("12t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 4, S("1234t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 5, S("12345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 0, 6, S("12345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 1, S("2t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 2, S("23t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 3, S("234t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 4, S("2345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 1, 5, S("2345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 2, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 2, 1, S("3t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 2, 2, S("34t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 2, 3, S("345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 2, 4, S("345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 4, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 4, 1, S("5t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 4, 2, S("5t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 5, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 5, 1, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 1, S("1t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 5, S("12345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 9, S("123456789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 10, S("1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 0, 11, S("1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 1, S("2t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 4, S("2345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 8, S("23456789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 9, S("234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 1, 10, S("234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 1, S("6t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 2, S("67t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 4, S("6789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 5, S("67890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 5, 6, S("67890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 9, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 9, 1, S("0t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 9, 2, S("0t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 10, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 10, 1, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 1, S("1t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 10, S("1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 19, S("1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 20, S("12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 0, 21, S("12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 1, S("2t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 9, S("234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 18, S("234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 19, S("2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 1, 20, S("2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 1, S("1t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 5, S("12345t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 9, S("123456789t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 10, S("1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 10, 11, S("1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 19, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 19, 1, S("0t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 19, 2, S("0t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 20, 0, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 20, 1, S("t"));
+    test(S("abcdefghijklmnopqrst"), 0, 19, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV(""), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV(""), 0, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 0, S(""));
+}
+
+template <class S, class SV>
+void test40()
+{
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 2, S("12"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 4, S("1234"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 0, 6, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 2, S("23"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 3, S("234"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 4, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 1, 5, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 2, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 2, 1, S("3"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 2, 2, S("34"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 2, 3, S("345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 2, 4, S("345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 4, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 4, 1, S("5"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 4, 2, S("5"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 5, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 5, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 9, S("123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 9, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 10, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 10, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 20, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV(""), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV(""), 0, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 2, S("12"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 4, S("1234"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 0, 6, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 2, S("23"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 3, S("234"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 4, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 1, 5, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 2, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 2, 1, S("3"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 2, 2, S("34"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 2, 3, S("345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 2, 4, S("345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 4, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 4, 1, S("5"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 4, 2, S("5"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 5, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 5, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 9, S("123456789"));
+}
+
+template <class S, class SV>
+void test41()
+{
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 0, 11, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 4, S("2345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 8, S("23456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 1, 10, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 1, S("6"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 2, S("67"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 4, S("6789"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 5, S("67890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 5, 6, S("67890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 9, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 9, 1, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 9, 2, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 10, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 10, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 1, S("2"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 9, S("234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 1, S("1"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 5, S("12345"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 9, S("123456789"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 19, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 19, 1, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 19, 2, S("0"));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 20, 0, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 20, 1, S(""));
+    test(S("abcdefghijklmnopqrst"), 0, 21, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 2, S("a12bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 4, S("a1234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 0, 6, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 2, S("a23bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 3, S("a234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 1, 5, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 2, 1, S("a3bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 2, 2, S("a34bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 2, 3, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 2, 4, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 4, 1, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 4, 2, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 0, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 8, S("a23456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 1, 10, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 1, S("a6bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 2, S("a67bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 4, S("a6789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 5, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 5, 6, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 9, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 9, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test42()
+{
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 10, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 19, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 19, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV(""), 0, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV(""), 0, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 1, S("a1cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 2, S("a12cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 4, S("a1234cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 5, S("a12345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 0, 6, S("a12345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 1, S("a2cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 2, S("a23cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 3, S("a234cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 4, S("a2345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 1, 5, S("a2345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 2, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 2, 1, S("a3cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 2, 2, S("a34cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 2, 3, S("a345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 2, 4, S("a345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 4, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 4, 1, S("a5cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 4, 2, S("a5cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 5, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 5, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 1, S("a1cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 5, S("a12345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 9, S("a123456789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 10, S("a1234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 0, 11, S("a1234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 1, S("a2cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 4, S("a2345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 8, S("a23456789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 9, S("a234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 1, 10, S("a234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 1, S("a6cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 2, S("a67cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 4, S("a6789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 5, S("a67890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 5, 6, S("a67890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 9, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 9, 1, S("a0cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 9, 2, S("a0cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 10, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 10, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 1, S("a1cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 10, S("a1234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 19, S("a1234567890123456789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 20, S("a12345678901234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 0, 21, S("a12345678901234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 1, S("a2cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 9, S("a234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 18, S("a234567890123456789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 19, S("a2345678901234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 1, 20, S("a2345678901234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 1, S("a1cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 5, S("a12345cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 9, S("a123456789cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 10, S("a1234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 10, 11, S("a1234567890cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 19, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 19, 1, S("a0cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 19, 2, S("a0cdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 20, 0, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 20, 1, S("acdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV(""), 0, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV(""), 0, 1, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 1, S("a1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 2, S("a12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 4, S("a1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 5, S("a12345klmnopqrst"));
+}
+
+template <class S, class SV>
+void test43()
+{
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 0, 6, S("a12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 1, S("a2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 2, S("a23klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 3, S("a234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 4, S("a2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 1, 5, S("a2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 2, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 2, 1, S("a3klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 2, 2, S("a34klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 2, 3, S("a345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 2, 4, S("a345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 4, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 4, 1, S("a5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 4, 2, S("a5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 5, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 5, 1, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 1, S("a1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 5, S("a12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 9, S("a123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 10, S("a1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 0, 11, S("a1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 1, S("a2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 4, S("a2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 8, S("a23456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 9, S("a234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 1, 10, S("a234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 1, S("a6klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 2, S("a67klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 4, S("a6789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 5, S("a67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 5, 6, S("a67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 9, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 9, 1, S("a0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 9, 2, S("a0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 10, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 10, 1, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 1, S("a1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 10, S("a1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 19, S("a1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 20, S("a12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 0, 21, S("a12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 1, S("a2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 9, S("a234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 18, S("a234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 19, S("a2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 1, 20, S("a2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 1, S("a1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 5, S("a12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 9, S("a123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 10, S("a1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 10, 11, S("a1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 19, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 19, 1, S("a0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 19, 2, S("a0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 20, 0, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 20, 1, S("aklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 9, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV(""), 0, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV(""), 0, 1, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 1, S("a1t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 2, S("a12t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 4, S("a1234t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 5, S("a12345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 0, 6, S("a12345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 1, S("a2t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 2, S("a23t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 3, S("a234t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 4, S("a2345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 1, 5, S("a2345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 2, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 2, 1, S("a3t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 2, 2, S("a34t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 2, 3, S("a345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 2, 4, S("a345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 4, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 4, 1, S("a5t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 4, 2, S("a5t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 5, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 5, 1, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 1, S("a1t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 5, S("a12345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 9, S("a123456789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 10, S("a1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 0, 11, S("a1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 1, S("a2t"));
+}
+
+template <class S, class SV>
+void test44()
+{
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 4, S("a2345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 8, S("a23456789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 9, S("a234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 1, 10, S("a234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 1, S("a6t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 2, S("a67t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 4, S("a6789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 5, S("a67890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 5, 6, S("a67890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 9, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 9, 1, S("a0t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 9, 2, S("a0t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 10, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 10, 1, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 1, S("a1t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 10, S("a1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 19, S("a1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 20, S("a12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 0, 21, S("a12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 1, S("a2t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 9, S("a234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 18, S("a234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 19, S("a2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 1, 20, S("a2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 1, S("a1t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 5, S("a12345t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 9, S("a123456789t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 10, S("a1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 10, 11, S("a1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 19, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 19, 1, S("a0t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 19, 2, S("a0t"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 20, 0, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 20, 1, S("at"));
+    test(S("abcdefghijklmnopqrst"), 1, 18, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV(""), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV(""), 0, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 2, S("a12"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 2, S("a23"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 3, S("a234"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 2, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 2, 1, S("a3"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 2, 2, S("a34"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 2, 3, S("a345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 2, 4, S("a345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 4, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 4, 1, S("a5"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 4, 2, S("a5"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 5, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 5, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 8, S("a23456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 1, 10, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+}
+
+template <class S, class SV>
+void test45()
+{
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 19, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV(""), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV(""), 0, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 2, S("a12"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 4, S("a1234"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 0, 6, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 2, S("a23"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 3, S("a234"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 4, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 1, 5, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 2, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 2, 1, S("a3"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 2, 2, S("a34"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 2, 3, S("a345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 2, 4, S("a345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 4, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 4, 1, S("a5"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 4, 2, S("a5"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 5, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 5, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 9, S("a123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 0, 11, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 4, S("a2345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 8, S("a23456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 1, 10, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 1, S("a6"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 2, S("a67"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 4, S("a6789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 5, S("a67890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 5, 6, S("a67890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 9, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 9, 1, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 9, 2, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 10, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 10, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 19, S("a1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 20, S("a12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 0, 21, S("a12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 1, S("a2"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 9, S("a234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 18, S("a234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 19, S("a2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 1, 20, S("a2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 1, S("a1"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 5, S("a12345"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 9, S("a123456789"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 10, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 10, 11, S("a1234567890"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 19, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 19, 1, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 19, 2, S("a0"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 20, 0, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 20, 1, S("a"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 2, S("abcdefghij12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 4, S("abcdefghij1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 0, 6, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 2, S("abcdefghij23klmnopqrst"));
+}
+
+template <class S, class SV>
+void test46()
+{
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 3, S("abcdefghij234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 1, 5, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 2, 1, S("abcdefghij3klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 2, 2, S("abcdefghij34klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 2, 3, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 2, 4, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 4, 1, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 4, 2, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 9, S("abcdefghij123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 0, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 8, S("abcdefghij23456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 1, 10, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 1, S("abcdefghij6klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 2, S("abcdefghij67klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 4, S("abcdefghij6789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 5, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 5, 6, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 9, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 9, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 19, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 19, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV(""), 0, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV(""), 0, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 1, S("abcdefghij1lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 2, S("abcdefghij12lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 4, S("abcdefghij1234lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 5, S("abcdefghij12345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 0, 6, S("abcdefghij12345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 1, S("abcdefghij2lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 2, S("abcdefghij23lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 3, S("abcdefghij234lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 4, S("abcdefghij2345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 1, 5, S("abcdefghij2345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 2, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 2, 1, S("abcdefghij3lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 2, 2, S("abcdefghij34lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 2, 3, S("abcdefghij345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 2, 4, S("abcdefghij345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 4, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 4, 1, S("abcdefghij5lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 4, 2, S("abcdefghij5lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 5, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 5, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 1, S("abcdefghij1lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 5, S("abcdefghij12345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 9, S("abcdefghij123456789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 10, S("abcdefghij1234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 0, 11, S("abcdefghij1234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 1, S("abcdefghij2lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 4, S("abcdefghij2345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 8, S("abcdefghij23456789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 9, S("abcdefghij234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 1, 10, S("abcdefghij234567890lmnopqrst"));
+}
+
+template <class S, class SV>
+void test47()
+{
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 1, S("abcdefghij6lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 2, S("abcdefghij67lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 4, S("abcdefghij6789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 5, S("abcdefghij67890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 5, 6, S("abcdefghij67890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 9, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 9, 1, S("abcdefghij0lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 9, 2, S("abcdefghij0lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 10, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 10, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 1, S("abcdefghij1lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 1, S("abcdefghij2lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 1, S("abcdefghij1lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 5, S("abcdefghij12345lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 19, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 19, 1, S("abcdefghij0lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 19, 2, S("abcdefghij0lmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 20, 0, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 20, 1, S("abcdefghijlmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV(""), 0, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV(""), 0, 1, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 1, S("abcdefghij1pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 2, S("abcdefghij12pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 4, S("abcdefghij1234pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 5, S("abcdefghij12345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 0, 6, S("abcdefghij12345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 1, S("abcdefghij2pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 2, S("abcdefghij23pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 3, S("abcdefghij234pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 4, S("abcdefghij2345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 1, 5, S("abcdefghij2345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 2, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 2, 1, S("abcdefghij3pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 2, 2, S("abcdefghij34pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 2, 3, S("abcdefghij345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 2, 4, S("abcdefghij345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 4, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 4, 1, S("abcdefghij5pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 4, 2, S("abcdefghij5pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 5, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 5, 1, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 1, S("abcdefghij1pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 5, S("abcdefghij12345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 9, S("abcdefghij123456789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 10, S("abcdefghij1234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 0, 11, S("abcdefghij1234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 1, S("abcdefghij2pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 4, S("abcdefghij2345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 8, S("abcdefghij23456789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 9, S("abcdefghij234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 1, 10, S("abcdefghij234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 1, S("abcdefghij6pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 2, S("abcdefghij67pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 4, S("abcdefghij6789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 5, S("abcdefghij67890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 5, 6, S("abcdefghij67890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 9, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 9, 1, S("abcdefghij0pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 9, 2, S("abcdefghij0pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 10, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 10, 1, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 1, S("abcdefghij1pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 1, S("abcdefghij2pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 1, S("abcdefghij1pqrst"));
+}
+
+template <class S, class SV>
+void test48()
+{
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 5, S("abcdefghij12345pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 19, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 19, 1, S("abcdefghij0pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 19, 2, S("abcdefghij0pqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 20, 0, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 20, 1, S("abcdefghijpqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV(""), 0, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV(""), 0, 1, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 1, S("abcdefghij1t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 2, S("abcdefghij12t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 4, S("abcdefghij1234t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 5, S("abcdefghij12345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 0, 6, S("abcdefghij12345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 1, S("abcdefghij2t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 2, S("abcdefghij23t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 3, S("abcdefghij234t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 4, S("abcdefghij2345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 1, 5, S("abcdefghij2345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 2, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 2, 1, S("abcdefghij3t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 2, 2, S("abcdefghij34t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 2, 3, S("abcdefghij345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 2, 4, S("abcdefghij345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 4, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 4, 1, S("abcdefghij5t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 4, 2, S("abcdefghij5t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 5, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 5, 1, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 1, S("abcdefghij1t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 5, S("abcdefghij12345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 9, S("abcdefghij123456789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 10, S("abcdefghij1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 0, 11, S("abcdefghij1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 1, S("abcdefghij2t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 4, S("abcdefghij2345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 8, S("abcdefghij23456789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 9, S("abcdefghij234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 1, 10, S("abcdefghij234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 1, S("abcdefghij6t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 2, S("abcdefghij67t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 4, S("abcdefghij6789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 5, S("abcdefghij67890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 5, 6, S("abcdefghij67890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 9, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 9, 1, S("abcdefghij0t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 9, 2, S("abcdefghij0t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 10, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 10, 1, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 1, S("abcdefghij1t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 1, S("abcdefghij2t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 1, S("abcdefghij1t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 5, S("abcdefghij12345t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 19, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 19, 1, S("abcdefghij0t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 19, 2, S("abcdefghij0t"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 20, 0, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 20, 1, S("abcdefghijt"));
+    test(S("abcdefghijklmnopqrst"), 10, 9, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 2, S("abcdefghij23"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 2, 0, S("abcdefghij"));
+}
+
+template <class S, class SV>
+void test49()
+{
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 4, 1, S("abcdefghij5"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 4, S("abcdefghij6789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 2, S("abcdefghij23"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 4, 1, S("abcdefghij5"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 4, S("abcdefghij6789"));
+}
+
+template <class S, class SV>
+void test50()
+{
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghijklmnopqrst"), 10, 11, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 2, S("abcdefghijklmnopqrs12t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 4, S("abcdefghijklmnopqrs1234t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 0, 6, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 2, S("abcdefghijklmnopqrs23t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 3, S("abcdefghijklmnopqrs234t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 1, 5, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 2, 1, S("abcdefghijklmnopqrs3t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 2, 2, S("abcdefghijklmnopqrs34t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 2, 3, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 2, 4, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 4, 1, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 4, 2, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrs23456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrs6t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrs67t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrs6789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrs1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrs234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrs1234567890t"));
+}
+
+template <class S, class SV>
+void test51()
+{
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV(""), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV(""), 0, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 2, S("abcdefghijklmnopqrs12"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 4, S("abcdefghijklmnopqrs1234"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 0, 6, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 2, S("abcdefghijklmnopqrs23"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 3, S("abcdefghijklmnopqrs234"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 4, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 1, 5, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 2, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 2, 1, S("abcdefghijklmnopqrs3"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 2, 2, S("abcdefghijklmnopqrs34"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 2, 3, S("abcdefghijklmnopqrs345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 2, 4, S("abcdefghijklmnopqrs345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 4, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 4, 1, S("abcdefghijklmnopqrs5"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 4, 2, S("abcdefghijklmnopqrs5"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 5, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 5, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrs123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrs23456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrs6"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrs67"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrs6789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrs67890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrs67890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrs1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrs12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrs12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrs234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrs2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrs2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrs123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV(""), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV(""), 0, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 2, S("abcdefghijklmnopqrs12"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 4, S("abcdefghijklmnopqrs1234"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 0, 6, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 2, S("abcdefghijklmnopqrs23"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 3, S("abcdefghijklmnopqrs234"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 4, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 1, 5, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 2, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 2, 1, S("abcdefghijklmnopqrs3"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 2, 2, S("abcdefghijklmnopqrs34"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 2, 3, S("abcdefghijklmnopqrs345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 2, 4, S("abcdefghijklmnopqrs345"));
+}
+
+template <class S, class SV>
+void test52()
+{
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 4, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 4, 1, S("abcdefghijklmnopqrs5"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 4, 2, S("abcdefghijklmnopqrs5"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 5, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 5, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrs123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrs2345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrs23456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrs6"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrs67"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrs6789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrs67890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrs67890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrs1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrs12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrs12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrs2"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrs234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrs234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrs2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrs2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrs1"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrs12345"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrs123456789"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrs1234567890"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrs0"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrs"));
+    test(S("abcdefghijklmnopqrst"), 19, 2, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 2, S("abcdefghijklmnopqrst12"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 4, S("abcdefghijklmnopqrst1234"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 0, 6, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 2, S("abcdefghijklmnopqrst23"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 3, S("abcdefghijklmnopqrst234"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 1, 5, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 2, 1, S("abcdefghijklmnopqrst3"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 2, 2, S("abcdefghijklmnopqrst34"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 2, 3, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 2, 4, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 4, 1, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 4, 2, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrst23456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrst6"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrst67"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrst6789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrst0"));
+}
+
+template <class S, class SV>
+void test53()
+{
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrst1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrst234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 2, S("abcdefghijklmnopqrst12"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 4, S("abcdefghijklmnopqrst1234"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 0, 6, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 2, S("abcdefghijklmnopqrst23"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 3, S("abcdefghijklmnopqrst234"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 1, 5, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 2, 1, S("abcdefghijklmnopqrst3"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 2, 2, S("abcdefghijklmnopqrst34"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 2, 3, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 2, 4, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 4, 1, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 4, 2, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 0, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 8, S("abcdefghijklmnopqrst23456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 1, 10, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 1, S("abcdefghijklmnopqrst6"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 2, S("abcdefghijklmnopqrst67"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 4, S("abcdefghijklmnopqrst6789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 5, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 5, 6, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 9, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 9, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrst1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrst234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+}
+
+template <class S, class SV>
+void test54()
+{
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 1, SV("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV(""), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV(""), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, SV("12345678901234567890"), 21, 0, S("can't happen"));
+}
+
+template <class S, class SV>
+void test55()
+{
+    test_npos(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 10, S("abcdefghi1234567890"));
+    test_npos(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 19, S("abcdefghi0"));
+    test_npos(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 20, S("abcdefghi"));
+    test_npos(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 20, S("abcdefghi"));
+    test_npos(S("abcdefghij"), 9, 1, SV("12345678901234567890"), 21, S("can't happen"));
+    test_npos(S("abcdefghij"), 9, 2, SV(""), 0, S("abcdefghi"));
+    test_npos(S("abcdefghij"), 9, 2, SV(""), 1, S("can't happen"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 0, S("abcdefghi12345"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 1, S("abcdefghi2345"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 2, S("abcdefghi345"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 4, S("abcdefghi5"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 5, S("abcdefghi"));
+    test_npos(S("abcdefghij"), 9, 2, SV("12345"), 6, S("can't happen"));
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    test0<S, SV>();
+    test1<S, SV>();
+    test2<S, SV>();
+    test3<S, SV>();
+    test4<S, SV>();
+    test5<S, SV>();
+    test6<S, SV>();
+    test7<S, SV>();
+    test8<S, SV>();
+    test9<S, SV>();
+    test10<S, SV>();
+    test11<S, SV>();
+    test12<S, SV>();
+    test13<S, SV>();
+    test14<S, SV>();
+    test15<S, SV>();
+    test16<S, SV>();
+    test17<S, SV>();
+    test18<S, SV>();
+    test19<S, SV>();
+    test20<S, SV>();
+    test21<S, SV>();
+    test22<S, SV>();
+    test23<S, SV>();
+    test24<S, SV>();
+    test25<S, SV>();
+    test26<S, SV>();
+    test27<S, SV>();
+    test28<S, SV>();
+    test29<S, SV>();
+    test30<S, SV>();
+    test31<S, SV>();
+    test32<S, SV>();
+    test33<S, SV>();
+    test34<S, SV>();
+    test35<S, SV>();
+    test36<S, SV>();
+    test37<S, SV>();
+    test38<S, SV>();
+    test39<S, SV>();
+    test40<S, SV>();
+    test41<S, SV>();
+    test42<S, SV>();
+    test43<S, SV>();
+    test44<S, SV>();
+    test45<S, SV>();
+    test46<S, SV>();
+    test47<S, SV>();
+    test48<S, SV>();
+    test49<S, SV>();
+    test50<S, SV>();
+    test51<S, SV>();
+    test52<S, SV>();
+    test53<S, SV>();
+    test54<S, SV>();
+    test55<S, SV>();
+    }
+#if TEST_STD_VER >= 11
+    {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    typedef std::basic_string_view<char, std::char_traits<char>> SV;
+    test0<S, SV>();
+    test1<S, SV>();
+    test2<S, SV>();
+    test3<S, SV>();
+    test4<S, SV>();
+    test5<S, SV>();
+    test6<S, SV>();
+    test7<S, SV>();
+    test8<S, SV>();
+    test9<S, SV>();
+    test10<S, SV>();
+    test11<S, SV>();
+    test12<S, SV>();
+    test13<S, SV>();
+    test14<S, SV>();
+    test15<S, SV>();
+    test16<S, SV>();
+    test17<S, SV>();
+    test18<S, SV>();
+    test19<S, SV>();
+    test20<S, SV>();
+    test21<S, SV>();
+    test22<S, SV>();
+    test23<S, SV>();
+    test24<S, SV>();
+    test25<S, SV>();
+    test26<S, SV>();
+    test27<S, SV>();
+    test28<S, SV>();
+    test29<S, SV>();
+    test30<S, SV>();
+    test31<S, SV>();
+    test32<S, SV>();
+    test33<S, SV>();
+    test34<S, SV>();
+    test35<S, SV>();
+    test36<S, SV>();
+    test37<S, SV>();
+    test38<S, SV>();
+    test39<S, SV>();
+    test40<S, SV>();
+    test41<S, SV>();
+    test42<S, SV>();
+    test43<S, SV>();
+    test44<S, SV>();
+    test45<S, SV>();
+    test46<S, SV>();
+    test47<S, SV>();
+    test48<S, SV>();
+    test49<S, SV>();
+    test50<S, SV>();
+    test51<S, SV>();
+    test52<S, SV>();
+    test53<S, SV>();
+    test54<S, SV>();
+    test55<S, SV>();
+    }
+#endif
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    S s0 = "ABCD";
+    S s;
+    SV sv = "EFGH";
+    char arr[] = "IJKL";
+
+    s = s0;
+    s.replace(0, 4, "CDEF", 0);    // calls replace(pos1, n1, const char *, len)
+    assert(s == "");
+
+    s = s0;
+    s.replace(0, 4, "QRST", 0, std::string::npos); // calls replace(pos1, n1, string("QRST"), pos, npos)
+    assert(s == "QRST");
+
+    s = s0;
+    s.replace(0, 4, sv, 0);  // calls replace(pos1, n1, T, pos, npos)
+    assert(s == sv);
+
+    s = s0;
+    s.replace(0, 4, sv, 0, std::string::npos);   // calls replace(pos1, n1, T, pos, npos)
+    assert(s == sv);
+
+    s = s0;
+    s.replace(0, 4, arr, 0);     // calls replace(pos1, n1, const char *, len)
+    assert(s == "");
+
+    s = s0;
+    s.replace(0, 4, arr, 0, std::string::npos);    // calls replace(pos1, n1, string("IJKL"), pos, npos)
+    assert(s == "IJKL");
+    }
+}
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer.pass.cpp
index 3beb074c0fd3..d09c9c2efd62 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -26,23 +25,32 @@ void
 test(S s, typename S::size_type pos, typename S::size_type n1,
      const typename S::value_type* str, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.replace(pos, n1, str);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos);
         typename S::size_type rlen = S::traits_type::length(str);
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.replace(pos, n1, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer_size.pass.cpp
index d961e9e8f76f..5c751285cb06 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_pointer_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -27,23 +26,32 @@ test(S s, typename S::size_type pos, typename S::size_type n1,
      const typename S::value_type* str, typename S::size_type n2,
      S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.replace(pos, n1, str, n2);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos);
         typename S::size_type rlen = n2;
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.replace(pos, n1, str, n2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_size_char.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_size_char.pass.cpp
index d4696fba8a83..75745dab61f6 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_size_char.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_size_char.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -27,23 +26,32 @@ test(S s, typename S::size_type pos, typename S::size_type n1,
      typename S::size_type n2, typename S::value_type c,
      S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos <= old_size)
     {
         s.replace(pos, n1, n2, c);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos <= old_size);
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos);
         typename S::size_type rlen = n2;
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos > old_size);
-        assert(s == s0);
+        try
+        {
+            s.replace(pos, n1, n2, c);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string.pass.cpp
index 1be45d8a6624..612e1e200c90 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -25,23 +24,32 @@ template <class S>
 void
 test(S s, typename S::size_type pos1, typename S::size_type n1, S str, S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos1 <= old_size)
     {
         s.replace(pos1, n1, str);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos1 <= old_size);
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos1);
         typename S::size_type rlen = str.size();
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos1 > old_size);
-        assert(s == s0);
+        try
+        {
+            s.replace(pos1, n1, str);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size);
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
diff --git a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string_size_size.pass.cpp b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string_size_size.pass.cpp
index 3f4bf450d858..b49b6f987b01 100644
--- a/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string_size_size.pass.cpp
+++ b/test/std/strings/basic.string/string.modifiers/string_replace/size_size_string_size_size.pass.cpp
@@ -7,7 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: libcpp-no-exceptions
 // <string>
 
 // basic_string<charT,traits,Allocator>&
@@ -29,23 +28,32 @@ test(S s, typename S::size_type pos1, typename S::size_type n1,
      S str, typename S::size_type pos2, typename S::size_type n2,
      S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos1 <= old_size && pos2 <= str.size())
     {
         s.replace(pos1, n1, str, pos2, n2);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos1 <= old_size && pos2 <= str.size());
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos1);
         typename S::size_type rlen = std::min(n2, str.size() - pos2);
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos1 > old_size || pos2 > str.size());
-        assert(s == s0);
+        try
+        {
+            s.replace(pos1, n1, str, pos2, n2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > str.size());
+            assert(s == s0);
+        }
     }
+#endif
 }
 
 template <class S>
@@ -54,23 +62,32 @@ test_npos(S s, typename S::size_type pos1, typename S::size_type n1,
      S str, typename S::size_type pos2,
      S expected)
 {
-    typename S::size_type old_size = s.size();
+    const typename S::size_type old_size = s.size();
     S s0 = s;
-    try
+    if (pos1 <= old_size && pos2 <= str.size())
     {
         s.replace(pos1, n1, str, pos2);
         LIBCPP_ASSERT(s.__invariants());
-        assert(pos1 <= old_size && pos2 <= str.size());
         assert(s == expected);
         typename S::size_type xlen = std::min(n1, old_size - pos1);
         typename S::size_type rlen = std::min(S::npos, str.size() - pos2);
         assert(s.size() == old_size - xlen + rlen);
     }
-    catch (std::out_of_range&)
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    else
     {
-        assert(pos1 > old_size || pos2 > str.size());
-        assert(s == s0);
+        try
+        {
+            s.replace(pos1, n1, str, pos2);
+            assert(false);
+        }
+        catch (std::out_of_range&)
+        {
+            assert(pos1 > old_size || pos2 > str.size());
+            assert(s == s0);
+        }
     }
+#endif
 }