5 files changed, 25 insertions, 10 deletions

diff --git a/contrib/libstdc++/include/bits/basic_string.h b/contrib/libstdc++/include/bits/basic_string.h
index dba1f566db508..90d2e2d5f421b 100644
--- a/contrib/libstdc++/include/bits/basic_string.h
+++ b/contrib/libstdc++/include/bits/basic_string.h
@@ -390,6 +390,16 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
       { _M_copy(__p, __k1, __k2 - __k1); }
 
+      static int
+      _S_compare(size_type __x, size_type __y)
+      {
+         if (__x > __y)
+            return 1;
+         if (__x < __y)
+            return -1;
+         return 0;
+      }
+
       void
       _M_mutate(size_type __pos, size_type __len1, size_type __len2);
 
@@ -1934,7 +1944,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 
 	int __r = traits_type::compare(_M_data(), __str.data(), __len);
 	if (!__r)
-	  __r =  __size - __osize;
+	  __r =  _S_compare(__size, __osize);
 	return __r;
       }
 
diff --git a/contrib/libstdc++/include/bits/basic_string.tcc b/contrib/libstdc++/include/bits/basic_string.tcc
index c2798efac11f7..78428c1eff69c 100644
--- a/contrib/libstdc++/include/bits/basic_string.tcc
+++ b/contrib/libstdc++/include/bits/basic_string.tcc
@@ -903,7 +903,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       const size_type __len = std::min(__n, __osize);
       int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
       if (!__r)
-	__r = __n - __osize;
+	__r = _S_compare(__n, __osize);
       return __r;
     }
 
@@ -921,7 +921,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       int __r = traits_type::compare(_M_data() + __pos1,
 				     __str.data() + __pos2, __len);
       if (!__r)
-	__r = __n1 - __n2;
+	__r = _S_compare(__n1, __n2);
       return __r;
     }
 
@@ -936,7 +936,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       const size_type __len = std::min(__size, __osize);
       int __r = traits_type::compare(_M_data(), __s, __len);
       if (!__r)
-	__r = __size - __osize;
+	__r = _S_compare(__size, __osize);
       return __r;
     }
 
@@ -952,7 +952,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       const size_type __len = std::min(__n1, __osize);
       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
       if (!__r)
-	__r = __n1 - __osize;
+	__r = _S_compare(__n1, __osize);
       return __r;
     }
 
@@ -968,7 +968,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       const size_type __len = std::min(__n1, __n2);
       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
       if (!__r)
-	__r = __n1 - __n2;
+	__r = _S_compare(__n1, __n2);
       return __r;
     }
 
diff --git a/contrib/libstdc++/include/bits/stl_algobase.h b/contrib/libstdc++/include/bits/stl_algobase.h
index 6f19febfe1e1d..2d89d0317c8ea 100644
--- a/contrib/libstdc++/include/bits/stl_algobase.h
+++ b/contrib/libstdc++/include/bits/stl_algobase.h
@@ -373,7 +373,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
    *  @param  first  An input iterator.
    *  @param  last   An input iterator.
    *  @param  result An output iterator.
-   *  @return   result + (first - last)
+   *  @return   result + (last - first)
    *
    *  This inline function will boil down to a call to @c memmove whenever
    *  possible.  Failing that, if random access iterators are passed, then the
diff --git a/contrib/libstdc++/include/bits/stl_tree.h b/contrib/libstdc++/include/bits/stl_tree.h
index 80cf7c4b08fb0..9e7a9ac31be2a 100644
--- a/contrib/libstdc++/include/bits/stl_tree.h
+++ b/contrib/libstdc++/include/bits/stl_tree.h
@@ -64,6 +64,8 @@
 #ifndef _TREE_H
 #define _TREE_H 1
 
+#pragma GCC system_header
+
 #include <bits/stl_algobase.h>
 #include <bits/allocator.h>
 #include <bits/stl_construct.h>
diff --git a/contrib/libstdc++/include/bits/stl_vector.h b/contrib/libstdc++/include/bits/stl_vector.h
index 1b794dc28ee19..60e352cad74b8 100644
--- a/contrib/libstdc++/include/bits/stl_vector.h
+++ b/contrib/libstdc++/include/bits/stl_vector.h
@@ -119,9 +119,12 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
       _Vector_base(size_t __n, const allocator_type& __a)
       : _M_impl(__a)
       {
-	this->_M_impl._M_start = this->_M_allocate(__n);
-	this->_M_impl._M_finish = this->_M_impl._M_start;
-	this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
+	  if (__n)
+	  {
+	    this->_M_impl._M_start = this->_M_allocate(__n);
+	    this->_M_impl._M_finish = this->_M_impl._M_start;
+	    this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
+	  }
       }
 
       ~_Vector_base()