53 files changed, 2622 insertions, 1071 deletions

diff --git a/contrib/lua/Makefile b/contrib/lua/Makefile
index 36447a0f61c7..fef1af4821e6 100644
--- a/contrib/lua/Makefile
+++ b/contrib/lua/Makefile
@@ -46,7 +46,7 @@ TO_MAN= lua.1 luac.1
 
 # Lua version and release.
 V= 5.4
-R= $V.2
+R= $V.4
 
 # Targets start here.
 all:	$(PLAT)
diff --git a/contrib/lua/README b/contrib/lua/README
index bc8a9d737d26..c394c69828b5 100644
--- a/contrib/lua/README
+++ b/contrib/lua/README
@@ -1,5 +1,5 @@
 
-This is Lua 5.4.2, released on 13 Nov 2020.
+This is Lua 5.4.4, released on 13 Jan 2022.
 
 For installation instructions, license details, and
 further information about Lua, see doc/readme.html.
diff --git a/contrib/lua/doc/contents.html b/contrib/lua/doc/contents.html
index 8ea0616b25ce..ab82eb4a9278 100644
--- a/contrib/lua/doc/contents.html
+++ b/contrib/lua/doc/contents.html
@@ -32,7 +32,7 @@ For a complete introduction to Lua programming, see the book
 
 <P>
 <SMALL>
-Copyright &copy; 2020 Lua.org, PUC-Rio.
+Copyright &copy; 2020&ndash;2022 Lua.org, PUC-Rio.
 Freely available under the terms of the
 <A HREF="http://www.lua.org/license.html">Lua license</A>.
 </SMALL>
@@ -396,6 +396,7 @@ Freely available under the terms of the
 <A HREF="manual.html#lua_callk">lua_callk</A><BR>
 <A HREF="manual.html#lua_checkstack">lua_checkstack</A><BR>
 <A HREF="manual.html#lua_close">lua_close</A><BR>
+<A HREF="manual.html#lua_closeslot">lua_closeslot</A><BR>
 <A HREF="manual.html#lua_compare">lua_compare</A><BR>
 <A HREF="manual.html#lua_concat">lua_concat</A><BR>
 <A HREF="manual.html#lua_copy">lua_copy</A><BR>
@@ -663,10 +664,10 @@ Freely available under the terms of the
 
 <P CLASS="footer">
 Last update:
-Tue Nov 10 20:58:52 UTC 2020
+Thu Jan 13 11:32:22 UTC 2022
 </P>
 <!--
-Last change: revised for Lua 5.4.2
+Last change: revised for Lua 5.4.4
 -->
 
 </BODY>
diff --git a/contrib/lua/doc/manual.html b/contrib/lua/doc/manual.html
index 6de396c41d1c..61a8220d7fd1 100644
--- a/contrib/lua/doc/manual.html
+++ b/contrib/lua/doc/manual.html
@@ -19,7 +19,7 @@ by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes
 
 <P>
 <SMALL>
-Copyright &copy; 2020 Lua.org, PUC-Rio.
+Copyright &copy; 2020&ndash;2022 Lua.org, PUC-Rio.
 Freely available under the terms of the
 <a href="http://www.lua.org/license.html">Lua license</a>.
 </SMALL>
@@ -143,6 +143,11 @@ The type <em>boolean</em> has two values, <b>false</b> and <b>true</b>.
 Both <b>nil</b> and <b>false</b> make a condition false;
 they are collectively called <em>false values</em>.
 Any other value makes a condition true.
+Despite its name,
+<b>false</b> is frequently used as an alternative to <b>nil</b>,
+with the key difference that <b>false</b> behaves
+like a regular value in a table,
+while a <b>nil</b> in a table represents an absent key.
 
 
 <p>
@@ -434,7 +439,7 @@ under certain events.
 You can change several aspects of the behavior
 of a value by setting specific fields in its metatable.
 For instance, when a non-numeric value is the operand of an addition,
-Lua checks for a function in the field "<code>__add</code>" of the value's metatable.
+Lua checks for a function in the field <code>__add</code> of the value's metatable.
 If it finds one,
 Lua calls this function to perform the addition.
 
@@ -901,7 +906,7 @@ For an object (table or userdata) to be finalized when collected,
 you must <em>mark</em> it for finalization.
 
 You mark an object for finalization when you set its metatable
-and the metatable has a field indexed by the string "<code>__gc</code>".
+and the metatable has a <code>__gc</code> metamethod.
 Note that if you set a metatable without a <code>__gc</code> field
 and later create that field in the metatable,
 the object will not be marked for finalization.
@@ -956,11 +961,8 @@ these marks have no effect.
 
 
 <p>
-Finalizers cannot yield.
-Except for that, they can do anything,
-such as raise errors, create new objects,
-or even run the garbage collector.
-However, because they can run in unpredictable times,
+Finalizers cannot yield nor run the garbage collector.
+Because they can run in unpredictable times,
 it is good practice to restrict each finalizer
 to the minimum necessary to properly release
 its associated resource.
@@ -1631,8 +1633,10 @@ before the adjustment
 
 
 <p>
-The assignment statement first evaluates all its expressions
-and only then the assignments are performed.
+If a variable is both assigned and read
+inside a multiple assignment,
+Lua ensures all reads get the value of the variable
+before the assignment.
 Thus the code
 
 <pre>
@@ -1657,6 +1661,14 @@ cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</c
 
 
 <p>
+Note that this guarantee covers only accesses
+syntactically inside the assignment statement.
+If a function or a metamethod called during the assignment
+changes the value of a variable,
+Lua gives no guarantees about the order of that access.
+
+
+<p>
 An assignment to a global name <code>x = val</code>
 is equivalent to the assignment
 <code>_ENV.x = val</code> (see <a href="#2.2">&sect;2.2</a>).
@@ -1992,16 +2004,8 @@ they are closed in the reverse order that they were declared.
 If there is any error while running a closing method,
 that error is handled like an error in the regular code
 where the variable was defined.
-However, Lua may call the method one more time.
-
-
-<p>
 After an error,
 the other pending closing methods will still be called.
-Errors in these methods
-interrupt the respective method and generate a warning,
-but are otherwise ignored;
-the error reported is only the original one.
 
 
 <p>
@@ -2419,16 +2423,21 @@ character is one byte.)
 <p>
 The length operator applied on a table
 returns a border in that table.
-A <em>border</em> in a table <code>t</code> is any natural number
+A <em>border</em> in a table <code>t</code> is any non-negative integer
 that satisfies the following condition:
 
 <pre>
-     (border == 0 or t[border] ~= nil) and t[border + 1] == nil
+     (border == 0 or t[border] ~= nil) and
+     (t[border + 1] == nil or border == math.maxinteger)
 </pre><p>
 In words,
-a border is any (natural) index present in the table
-that is followed by an absent index
-(or zero, when index 1 is absent).
+a border is any positive integer index present in the table
+that is followed by an absent index,
+plus two limit cases:
+zero, when index 1 is absent;
+and the maximum value for an integer, when that index is present.
+Note that keys that are not positive integers
+do not interfere with borders.
 
 
 <p>
@@ -2439,12 +2448,9 @@ The table <code>{10, 20, 30, nil, 50}</code> has two borders (3 and 5),
 and therefore it is not a sequence.
 (The <b>nil</b> at index 4 is called a <em>hole</em>.)
 The table <code>{nil, 20, 30, nil, nil, 60, nil}</code>
-has three borders (0, 3, and 6) and three holes
-(at indices 1, 4, and 5),
+has three borders (0, 3, and 6),
 so it is not a sequence, too.
 The table <code>{}</code> is a sequence with border 0.
-Note that non-natural keys do not interfere
-with whether a table is a sequence.
 
 
 <p>
@@ -2462,7 +2468,7 @@ the memory addresses of its non-numeric keys.)
 <p>
 The computation of the length of a table
 has a guaranteed worst time of <em>O(log n)</em>,
-where <em>n</em> is the largest natural key in the table.
+where <em>n</em> is the largest integer key in the table.
 
 
 <p>
@@ -3763,6 +3769,29 @@ will probably need to close states as soon as they are not needed.
 
 
 
+<hr><h3><a name="lua_closeslot"><code>lua_closeslot</code></a></h3><p>
+<span class="apii">[-0, +0, <em>e</em>]</span>
+<pre>void lua_closeslot (lua_State *L, int index);</pre>
+
+<p>
+Close the to-be-closed slot at the given index and set its value to <b>nil</b>.
+The index must be the last index previously marked to be closed
+(see <a href="#lua_toclose"><code>lua_toclose</code></a>) that is still active (that is, not closed yet).
+
+
+<p>
+A <code>__close</code> metamethod cannot yield
+when called through this function.
+
+
+<p>
+(Exceptionally, this function was introduced in release 5.4.3.
+It is not present in previous 5.4 releases.)
+
+
+
+
+
 <hr><h3><a name="lua_compare"><code>lua_compare</code></a></h3><p>
 <span class="apii">[-0, +0, <em>e</em>]</span>
 <pre>int lua_compare (lua_State *L, int index1, int index2, int op);</pre>
@@ -3959,6 +3988,10 @@ For more details about these options,
 see <a href="#pdf-collectgarbage"><code>collectgarbage</code></a>.
 
 
+<p>
+This function should not be called by a finalizer.
+
+
 
 
 
@@ -4657,11 +4690,7 @@ except that it allows the called function to yield (see <a href="#4.5">&sect;4.5
 
 <p>
 Pops <code>n</code> elements from the stack.
-
-
-<p>
-This function can run arbitrary code when removing an index
-marked as to-be-closed from the stack.
+It is implemented as a macro over <a href="#lua_settop"><code>lua_settop</code></a>.
 
 
 
@@ -5140,10 +5169,12 @@ and then pops the top element.
 Resets a thread, cleaning its call stack and closing all pending
 to-be-closed variables.
 Returns a status code:
-<a href="#pdf-LUA_OK"><code>LUA_OK</code></a> for no errors in closing methods,
+<a href="#pdf-LUA_OK"><code>LUA_OK</code></a> for no errors in the thread
+(either the original error that stopped the thread or
+errors in closing methods),
 or an error status otherwise.
 In case of error,
-leaves the error object on the top of the stack,
+leaves the error object on the top of the stack.
 
 
 
@@ -5466,28 +5497,24 @@ otherwise, returns <code>NULL</code>.
 
 <p>
 Marks the given index in the stack as a
-to-be-closed "variable" (see <a href="#3.3.8">&sect;3.3.8</a>).
+to-be-closed slot (see <a href="#3.3.8">&sect;3.3.8</a>).
 Like a to-be-closed variable in Lua,
-the value at that index in the stack will be closed
+the value at that slot in the stack will be closed
 when it goes out of scope.
 Here, in the context of a C function,
 to go out of scope means that the running function returns to Lua,
-there is an error,
-or the index is removed from the stack through
-<a href="#lua_settop"><code>lua_settop</code></a> or <a href="#lua_pop"><code>lua_pop</code></a>.
-An index marked as to-be-closed should not be removed from the stack
-by any other function in the API except <a href="#lua_settop"><code>lua_settop</code></a> or <a href="#lua_pop"><code>lua_pop</code></a>.
+or there is an error,
+or the slot is removed from the stack through
+<a href="#lua_settop"><code>lua_settop</code></a> or <a href="#lua_pop"><code>lua_pop</code></a>,
+or there is a call to <a href="#lua_closeslot"><code>lua_closeslot</code></a>.
+A slot marked as to-be-closed should not be removed from the stack
+by any other function in the API except <a href="#lua_settop"><code>lua_settop</code></a> or <a href="#lua_pop"><code>lua_pop</code></a>,
+unless previously deactivated by <a href="#lua_closeslot"><code>lua_closeslot</code></a>.
 
 
 <p>
 This function should not be called for an index
-that is equal to or below an active to-be-closed index.
-
-
-<p>
-In the case of an out-of-memory error,
-the value in the given index is immediately closed,
-as if it was already marked.
+that is equal to or below an active to-be-closed slot.
 
 
 <p>
@@ -5495,7 +5522,7 @@ Note that, both in case of errors and of a regular return,
 by the time the <code>__close</code> metamethod runs,
 the C&nbsp;stack was already unwound,
 so that any automatic C&nbsp;variable declared in the calling function
-will be out of scope.
+(e.g., a buffer) will be out of scope.
 
 
 
@@ -5919,7 +5946,10 @@ information about a function or an activation record.
 <a href="#lua_getstack"><code>lua_getstack</code></a> fills only the private part
 of this structure, for later use.
 To fill the other fields of <a href="#lua_Debug"><code>lua_Debug</code></a> with useful information,
-you must call <a href="#lua_getinfo"><code>lua_getinfo</code></a>.
+you must call <a href="#lua_getinfo"><code>lua_getinfo</code></a> with an appropriate parameter.
+(Specifically, to get a field,
+you must add the letter between parentheses in the field's comment
+to the parameter <code>what</code> of <a href="#lua_getinfo"><code>lua_getinfo</code></a>.)
 
 
 <p>
@@ -6096,11 +6126,25 @@ you can write the following code:
 <p>
 Each character in the string <code>what</code>
 selects some fields of the structure <code>ar</code> to be filled or
-a value to be pushed on the stack:
+a value to be pushed on the stack.
+(These characters are also documented in the declaration of
+the structure <a href="#lua_Debug"><code>lua_Debug</code></a>,
+between parentheses in the comments following each field.)
 
 <ul>
 
-<li><b>'<code>n</code>': </b> fills in the field <code>name</code> and <code>namewhat</code>;
+<li><b>'<code>f</code>': </b>
+pushes onto the stack the function that is
+running at the given level;
+</li>
+
+<li><b>'<code>l</code>': </b> fills in the field <code>currentline</code>;
+</li>
+
+<li><b>'<code>n</code>': </b> fills in the fields <code>name</code> and <code>namewhat</code>;
+</li>
+
+<li><b>'<code>r</code>': </b> fills in the fields <code>ftransfer</code> and <code>ntransfer</code>;
 </li>
 
 <li><b>'<code>S</code>': </b>
@@ -6108,9 +6152,6 @@ fills in the fields <code>source</code>, <code>short_src</code>,
 <code>linedefined</code>, <code>lastlinedefined</code>, and <code>what</code>;
 </li>
 
-<li><b>'<code>l</code>': </b> fills in the field <code>currentline</code>;
-</li>
-
 <li><b>'<code>t</code>': </b> fills in the field <code>istailcall</code>;
 </li>
 
@@ -6118,25 +6159,13 @@ fills in the fields <code>source</code>, <code>short_src</code>,
 <code>nups</code>, <code>nparams</code>, and <code>isvararg</code>;
 </li>
 
-<li><b>'<code>f</code>': </b>
-pushes onto the stack the function that is
-running at the given level;
-</li>
-
 <li><b>'<code>L</code>': </b>
-pushes onto the stack a table whose indices are the
-numbers of the lines that are valid on the function.
-(A <em>valid line</em> is a line with some associated code,
-that is, a line where you can put a break point.
-Non-valid lines include empty lines and comments.)
-
-
-<p>
+pushes onto the stack a table whose indices are
+the lines on the function with some associated code,
+that is, the lines where you can put a break point.
+(Lines with no code include empty lines and comments.)
 If this option is given together with option '<code>f</code>',
 its table is pushed after the function.
-
-
-<p>
 This is the only option that can raise a memory error.
 </li>
 
@@ -6494,7 +6523,7 @@ Adds the byte <code>c</code> to the buffer <code>B</code>
 
 
 <hr><h3><a name="luaL_addgsub"><code>luaL_addgsub</code></a></h3><p>
-<span class="apii">[-0, +0, <em>m</em>]</span>
+<span class="apii">[-?, +?, <em>m</em>]</span>
 <pre>const void luaL_addgsub (luaL_Buffer *B, const char *s,
                          const char *p, const char *r);</pre>
 
@@ -6548,7 +6577,7 @@ to the buffer <code>B</code>
 
 
 <hr><h3><a name="luaL_addvalue"><code>luaL_addvalue</code></a></h3><p>
-<span class="apii">[-1, +?, <em>m</em>]</span>
+<span class="apii">[-?, +?, <em>m</em>]</span>
 <pre>void luaL_addvalue (luaL_Buffer *B);</pre>
 
 <p>
@@ -6702,7 +6731,7 @@ Note that any addition to the buffer may invalidate this address.
 
 
 <hr><h3><a name="luaL_buffinit"><code>luaL_buffinit</code></a></h3><p>
-<span class="apii">[-0, +0, &ndash;]</span>
+<span class="apii">[-0, +?, &ndash;]</span>
 <pre>void luaL_buffinit (lua_State *L, luaL_Buffer *B);</pre>
 
 <p>
@@ -6740,7 +6769,7 @@ Equivalent to the sequence
 
 
 <hr><h3><a name="luaL_buffsub"><code>luaL_buffsub</code></a></h3><p>
-<span class="apii">[-0, +0, &ndash;]</span>
+<span class="apii">[-?, +?, &ndash;]</span>
 <pre>void luaL_buffsub (luaL_Buffer *B, int n);</pre>
 
 <p>
@@ -7543,6 +7572,11 @@ on top of the library table.
 These values are popped from the stack after the registration.
 
 
+<p>
+A function with a <code>NULL</code> value represents a placeholder,
+which is filled with <b>false</b>.
+
+
 
 
 
@@ -7905,6 +7939,10 @@ See <a href="#2.5">&sect;2.5</a> for more details about garbage collection
 and some of these options.
 
 
+<p>
+This function should not be called by a finalizer.
+
+
 
 
 <p>
@@ -7922,7 +7960,7 @@ to its caller.
 
 <p>
 <hr><h3><a name="pdf-error"><code>error (message [, level])</code></a></h3>
-Raises an error (see <a href="#2.3">&sect;2.3</a>) with @{message} as the error object.
+Raises an error (see <a href="#2.3">&sect;2.3</a>) with <code>message</code> as the error object.
 This function never returns.
 
 
@@ -8097,9 +8135,8 @@ use a numerical <b>for</b>.)
 
 
 <p>
-The behavior of <code>next</code> is undefined if,
-during the traversal,
-you assign any value to a non-existent field in the table.
+You should not assign any value to a non-existent field in a table
+during its traversal.
 You may however modify existing fields.
 In particular, you may set existing fields to nil.
 
@@ -8145,7 +8182,7 @@ This means that any error inside&nbsp;<code>f</code> is not propagated;
 instead, <code>pcall</code> catches the error
 and returns a status code.
 Its first result is the status code (a boolean),
-which is true if the call succeeds without errors.
+which is <b>true</b> if the call succeeds without errors.
 In such case, <code>pcall</code> also returns all results from the call,
 after this first result.
 In case of any error, <code>pcall</code> returns <b>false</b> plus the error object.
@@ -8398,7 +8435,9 @@ that is,
 closes all its pending to-be-closed variables
 and puts the coroutine in a dead state.
 The given coroutine must be dead or suspended.
-In case of error closing some variable,
+In case of error
+(either the original error that stopped the coroutine or
+errors in closing methods),
 returns <b>false</b> plus the error object;
 otherwise returns <b>true</b>.
 
@@ -8423,7 +8462,7 @@ an object with type <code>"thread"</code>.
 
 
 <p>
-Returns true when the coroutine <code>co</code> can yield.
+Returns <b>true</b> when the coroutine <code>co</code> can yield.
 The default for <code>co</code> is the running coroutine.
 
 
@@ -8467,7 +8506,7 @@ If there is any error,
 
 <p>
 Returns the running coroutine plus a boolean,
-true when the running coroutine is the main one.
+<b>true</b> when the running coroutine is the main one.
 
 
 
@@ -9005,7 +9044,7 @@ otherwise, it returns <b>fail</b>.
 A third, optional numeric argument <code>init</code> specifies
 where to start the search;
 its default value is&nbsp;1 and can be negative.
-A value of <b>true</b> as a fourth, optional argument <code>plain</code>
+A <b>true</b> as a fourth, optional argument <code>plain</code>
 turns off the pattern matching facilities,
 so the function does a plain "find substring" operation,
 with no characters in <code>pattern</code> being considered magic.
@@ -9030,8 +9069,10 @@ following the description given in its first argument,
 which must be a string.
 The format string follows the same rules as the ISO&nbsp;C function <code>sprintf</code>.
 The only differences are that the conversion specifiers and modifiers
-<code>*</code>, <code>h</code>, <code>L</code>, <code>l</code>, and <code>n</code> are not supported
+<code>F</code>, <code>n</code>, <code>*</code>, <code>h</code>, <code>L</code>, and <code>l</code> are not supported
 and that there is an extra specifier, <code>q</code>.
+Both width and precision, when present,
+are limited to two digits.
 
 
 <p>
@@ -9055,7 +9096,7 @@ may produce the string:
      "a string with \"quotes\" and \
       new line"
 </pre><p>
-This specifier does not support modifiers (flags, width, length).
+This specifier does not support modifiers (flags, width, precision).
 
 
 <p>
@@ -9960,23 +10001,23 @@ from <code>list[1]</code> to <code>list[#list]</code>.
 If <code>comp</code> is given,
 then it must be a function that receives two list elements
 and returns true when the first element must come
-before the second in the final order
-(so that, after the sort,
-<code>i &lt; j</code> implies <code>not comp(list[j],list[i])</code>).
+before the second in the final order,
+so that, after the sort,
+<code>i &lt;= j</code> implies <code>not comp(list[j],list[i])</code>.
 If <code>comp</code> is not given,
 then the standard Lua operator <code>&lt;</code> is used instead.
 
 
 <p>
-Note that the <code>comp</code> function must define
-a strict partial order over the elements in the list;
-that is, it must be asymmetric and transitive.
-Otherwise, no valid sort may be possible.
+The <code>comp</code> function must define a consistent order;
+more formally, the function must define a strict weak order.
+(A weak order is similar to a total order,
+but it can equate different elements for comparison purposes.)
 
 
 <p>
 The sort algorithm is not stable:
-elements considered equal by the given order
+Different elements considered equal by the given order
 may have their relative positions changed by the sort.
 
 
@@ -10346,7 +10387,7 @@ or <b>fail</b> if <code>x</code> is not a number.
 
 <p>
 Returns a boolean,
-true if and only if integer <code>m</code> is below integer <code>n</code> when
+<b>true</b> if and only if integer <code>m</code> is below integer <code>n</code> when
 they are compared as unsigned integers.
 
 
@@ -11908,10 +11949,10 @@ and LiteralString, see <a href="#3.1">&sect;3.1</a>.)
 
 <P CLASS="footer">
 Last update:
-Fri Nov 13 15:35:22 UTC 2020
+Thu Jan 13 11:33:16 UTC 2022
 </P>
 <!--
-Last change: revised for Lua 5.4.2
+Last change: revised for Lua 5.4.4
 -->
 
 </body></html>
diff --git a/contrib/lua/doc/readme.html b/contrib/lua/doc/readme.html
index e20a9bda138a..8afe38de923b 100644
--- a/contrib/lua/doc/readme.html
+++ b/contrib/lua/doc/readme.html
@@ -110,7 +110,7 @@ Here are the details.
 <OL>
 <LI>
 Open a terminal window and move to
-the top-level directory, which is named <TT>lua-5.4.2</TT>.
+the top-level directory, which is named <TT>lua-5.4.4</TT>.
 The <TT>Makefile</TT> there controls both the build process and the installation process.
 <P>
 <LI>
@@ -303,7 +303,7 @@ For details, see
 <A HREF="http://www.lua.org/license.html">this</A>.
 
 <BLOCKQUOTE STYLE="padding-bottom: 0em">
-Copyright &copy; 1994&ndash;2020 Lua.org, PUC-Rio.
+Copyright &copy; 1994&ndash;2022 Lua.org, PUC-Rio.
 
 <P>
 Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -330,10 +330,10 @@ THE SOFTWARE.
 
 <P CLASS="footer">
 Last update:
-Tue Nov 10 20:55:28 UTC 2020
+Mon Jan  3 09:54:18 UTC 2022
 </P>
 <!--
-Last change: revised for Lua 5.4.2
+Last change: revised for Lua 5.4.4
 -->
 
 </BODY>
diff --git a/contrib/lua/src/lapi.c b/contrib/lua/src/lapi.c
index c824da27cbc4..5ee65792d277 100644
--- a/contrib/lua/src/lapi.c
+++ b/contrib/lua/src/lapi.c
@@ -39,7 +39,7 @@ const char lua_ident[] =
 
 
 /*
-** Test for a valid index.
+** Test for a valid index (one that is not the 'nilvalue').
 ** '!ttisnil(o)' implies 'o != &G(L)->nilvalue', so it is not needed.
 ** However, it covers the most common cases in a faster way.
 */
@@ -53,6 +53,10 @@ const char lua_ident[] =
 #define isupvalue(i)		((i) < LUA_REGISTRYINDEX)
 
 
+/*
+** Convert an acceptable index to a pointer to its respective value.
+** Non-valid indices return the special nil value 'G(L)->nilvalue'.
+*/
 static TValue *index2value (lua_State *L, int idx) {
   CallInfo *ci = L->ci;
   if (idx > 0) {
@@ -70,21 +74,28 @@ static TValue *index2value (lua_State *L, int idx) {
   else {  /* upvalues */
     idx = LUA_REGISTRYINDEX - idx;
     api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
-    if (ttislcf(s2v(ci->func)))  /* light C function? */
-      return &G(L)->nilvalue;  /* it has no upvalues */
-    else {
+    if (ttisCclosure(s2v(ci->func))) {  /* C closure? */
       CClosure *func = clCvalue(s2v(ci->func));
-      return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : &G(L)->nilvalue;
+      return (idx <= func->nupvalues) ? &func->upvalue[idx-1]
+                                      : &G(L)->nilvalue;
+    }
+    else {  /* light C function or Lua function (through a hook)?) */
+      api_check(L, ttislcf(s2v(ci->func)), "caller not a C function");
+      return &G(L)->nilvalue;  /* no upvalues */
     }
   }
 }
 
 
-static StkId index2stack (lua_State *L, int idx) {
+
+/*
+** Convert a valid actual index (not a pseudo-index) to its address.
+*/
+l_sinline StkId index2stack (lua_State *L, int idx) {
   CallInfo *ci = L->ci;
   if (idx > 0) {
     StkId o = ci->func + idx;
-    api_check(L, o < L->top, "unacceptable index");
+    api_check(L, o < L->top, "invalid index");
     return o;
   }
   else {    /* non-positive index */
@@ -172,7 +183,7 @@ LUA_API int lua_gettop (lua_State *L) {
 
 LUA_API void lua_settop (lua_State *L, int idx) {
   CallInfo *ci;
-  StkId func;
+  StkId func, newtop;
   ptrdiff_t diff;  /* difference for new top */
   lua_lock(L);
   ci = L->ci;
@@ -187,9 +198,26 @@ LUA_API void lua_settop (lua_State *L, int idx) {
     api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
     diff = idx + 1;  /* will "subtract" index (as it is negative) */
   }
-  if (diff < 0 && hastocloseCfunc(ci->nresults))
-    luaF_close(L, L->top + diff, LUA_OK);
-  L->top += diff;  /* correct top only after closing any upvalue */
+  api_check(L, L->tbclist < L->top, "previous pop of an unclosed slot");
+  newtop = L->top + diff;
+  if (diff < 0 && L->tbclist >= newtop) {
+    lua_assert(hastocloseCfunc(ci->nresults));
+    luaF_close(L, newtop, CLOSEKTOP, 0);
+  }
+  L->top = newtop;  /* correct top only after closing any upvalue */
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_closeslot (lua_State *L, int idx) {
+  StkId level;
+  lua_lock(L);
+  level = index2stack(L, idx);
+  api_check(L, hastocloseCfunc(L->ci->nresults) && L->tbclist == level,
+     "no variable to close at given level");
+  luaF_close(L, level, CLOSEKTOP, 0);
+  level = index2stack(L, idx);  /* stack may be moved */
+  setnilvalue(s2v(level));
   lua_unlock(L);
 }
 
@@ -200,7 +228,7 @@ LUA_API void lua_settop (lua_State *L, int idx) {
 ** Note that we move(copy) only the value inside the stack.
 ** (We do not move additional fields that may exist.)
 */
-static void reverse (lua_State *L, StkId from, StkId to) {
+l_sinline void reverse (lua_State *L, StkId from, StkId to) {
   for (; from < to; from++, to--) {
     TValue temp;
     setobj(L, &temp, s2v(from));
@@ -420,7 +448,7 @@ LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
 }
 
 
-static void *touserdata (const TValue *o) {
+l_sinline void *touserdata (const TValue *o) {
   switch (ttype(o)) {
     case LUA_TUSERDATA: return getudatamem(uvalue(o));
     case LUA_TLIGHTUSERDATA: return pvalue(o);
@@ -612,7 +640,7 @@ LUA_API int lua_pushthread (lua_State *L) {
 */
 
 
-static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
+l_sinline int auxgetstr (lua_State *L, const TValue *t, const char *k) {
   const TValue *slot;
   TString *str = luaS_new(L, k);
   if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
@@ -629,11 +657,21 @@ static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
 }
 
 
+/*
+** Get the global table in the registry. Since all predefined
+** indices in the registry were inserted right when the registry
+** was created and never removed, they must always be in the array
+** part of the registry.
+*/
+#define getGtable(L)  \
+	(&hvalue(&G(L)->l_registry)->array[LUA_RIDX_GLOBALS - 1])
+
+
 LUA_API int lua_getglobal (lua_State *L, const char *name) {
-  Table *reg;
+  const TValue *G;
   lua_lock(L);
-  reg = hvalue(&G(L)->l_registry);
-  return auxgetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
+  G = getGtable(L);
+  return auxgetstr(L, G, name);
 }
 
 
@@ -677,7 +715,7 @@ LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
 }
 
 
-static int finishrawget (lua_State *L, const TValue *val) {
+l_sinline int finishrawget (lua_State *L, const TValue *val) {
   if (isempty(val))  /* avoid copying empty items to the stack */
     setnilvalue(s2v(L->top));
   else
@@ -811,10 +849,10 @@ static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
 
 
 LUA_API void lua_setglobal (lua_State *L, const char *name) {
-  Table *reg;
+  const TValue *G;
   lua_lock(L);  /* unlock done in 'auxsetstr' */
-  reg = hvalue(&G(L)->l_registry);
-  auxsetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
+  G = getGtable(L);
+  auxsetstr(L, G, name);
 }
 
 
@@ -861,12 +899,10 @@ LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
 
 static void aux_rawset (lua_State *L, int idx, TValue *key, int n) {
   Table *t;
-  TValue *slot;
   lua_lock(L);
   api_checknelems(L, n);
   t = gettable(L, idx);
-  slot = luaH_set(L, t, key);
-  setobj2t(L, slot, s2v(L->top - 1));
+  luaH_set(L, t, key, s2v(L->top - 1));
   invalidateTMcache(t);
   luaC_barrierback(L, obj2gco(t), s2v(L->top - 1));
   L->top -= n;
@@ -1063,8 +1099,7 @@ LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
     LClosure *f = clLvalue(s2v(L->top - 1));  /* get newly created function */
     if (f->nupvalues >= 1) {  /* does it have an upvalue? */
       /* get global table from registry */
-      Table *reg = hvalue(&G(L)->l_registry);
-      const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
+      const TValue *gt = getGtable(L);
       /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
       setobj(L, f->upvals[0]->v, gt);
       luaC_barrier(L, f->upvals[0], gt);
@@ -1101,18 +1136,19 @@ LUA_API int lua_status (lua_State *L) {
 LUA_API int lua_gc (lua_State *L, int what, ...) {
   va_list argp;
   int res = 0;
-  global_State *g;
+  global_State *g = G(L);
+  if (g->gcstp & GCSTPGC)  /* internal stop? */
+    return -1;  /* all options are invalid when stopped */
   lua_lock(L);
-  g = G(L);
   va_start(argp, what);
   switch (what) {
     case LUA_GCSTOP: {
-      g->gcrunning = 0;
+      g->gcstp = GCSTPUSR;  /* stopped by the user */
       break;
     }
     case LUA_GCRESTART: {
       luaE_setdebt(g, 0);
-      g->gcrunning = 1;
+      g->gcstp = 0;  /* (GCSTPGC must be already zero here) */
       break;
     }
     case LUA_GCCOLLECT: {
@@ -1131,8 +1167,8 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
     case LUA_GCSTEP: {
       int data = va_arg(argp, int);
       l_mem debt = 1;  /* =1 to signal that it did an actual step */
-      lu_byte oldrunning = g->gcrunning;
-      g->gcrunning = 1;  /* allow GC to run */
+      lu_byte oldstp = g->gcstp;
+      g->gcstp = 0;  /* allow GC to run (GCSTPGC must be zero here) */
       if (data == 0) {
         luaE_setdebt(g, 0);  /* do a basic step */
         luaC_step(L);
@@ -1142,7 +1178,7 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
         luaE_setdebt(g, debt);
         luaC_checkGC(L);
       }
-      g->gcrunning = oldrunning;  /* restore previous state */
+      g->gcstp = oldstp;  /* restore previous state */
       if (debt > 0 && g->gcstate == GCSpause)  /* end of cycle? */
         res = 1;  /* signal it */
       break;
@@ -1160,7 +1196,7 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
       break;
     }
     case LUA_GCISRUNNING: {
-      res = g->gcrunning;
+      res = gcrunning(g);
       break;
     }
     case LUA_GCGEN: {
@@ -1240,8 +1276,7 @@ LUA_API void lua_toclose (lua_State *L, int idx) {
   lua_lock(L);
   o = index2stack(L, idx);
   nresults = L->ci->nresults;
-  api_check(L, L->openupval == NULL || uplevel(L->openupval) <= o,
-               "marked index below or equal new one");
+  api_check(L, L->tbclist < o, "given index below or equal a marked one");
   luaF_newtbcupval(L, o);  /* create new to-be-closed upvalue */
   if (!hastocloseCfunc(nresults))  /* function not marked yet? */
     L->ci->nresults = codeNresults(nresults);  /* mark it */
diff --git a/contrib/lua/src/lapi.h b/contrib/lua/src/lapi.h
index 41216b270902..9e99cc44824d 100644
--- a/contrib/lua/src/lapi.h
+++ b/contrib/lua/src/lapi.h
@@ -42,6 +42,8 @@
 
 #define hastocloseCfunc(n)	((n) < LUA_MULTRET)
 
+/* Map [-1, inf) (range of 'nresults') into (-inf, -2] */
 #define codeNresults(n)		(-(n) - 3)
+#define decodeNresults(n)	(-(n) - 3)
 
 #endif
diff --git a/contrib/lua/src/lauxlib.c b/contrib/lua/src/lauxlib.c
index 73504389e1a4..8ed1da1122fc 100644
--- a/contrib/lua/src/lauxlib.c
+++ b/contrib/lua/src/lauxlib.c
@@ -190,7 +190,7 @@ LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
 }
 
 
-int luaL_typeerror (lua_State *L, int arg, const char *tname) {
+LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) {
   const char *msg;
   const char *typearg;  /* name for the type of the actual argument */
   if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
@@ -378,7 +378,7 @@ LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
 ** but without 'msg'.)
 */
 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
-  if (!lua_checkstack(L, space)) {
+  if (l_unlikely(!lua_checkstack(L, space))) {
     if (msg)
       luaL_error(L, "stack overflow (%s)", msg);
     else
@@ -388,20 +388,20 @@ LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
 
 
 LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {
-  if (lua_type(L, arg) != t)
+  if (l_unlikely(lua_type(L, arg) != t))
     tag_error(L, arg, t);
 }
 
 
 LUALIB_API void luaL_checkany (lua_State *L, int arg) {
-  if (lua_type(L, arg) == LUA_TNONE)
+  if (l_unlikely(lua_type(L, arg) == LUA_TNONE))
     luaL_argerror(L, arg, "value expected");
 }
 
 
 LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {
   const char *s = lua_tolstring(L, arg, len);
-  if (!s) tag_error(L, arg, LUA_TSTRING);
+  if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING);
   return s;
 }
 
@@ -420,7 +420,7 @@ LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,
 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {
   int isnum;
   lua_Number d = lua_tonumberx(L, arg, &isnum);
-  if (!isnum)
+  if (l_unlikely(!isnum))
     tag_error(L, arg, LUA_TNUMBER);
   return d;
 }
@@ -442,7 +442,7 @@ static void interror (lua_State *L, int arg) {
 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {
   int isnum;
   lua_Integer d = lua_tointegerx(L, arg, &isnum);
-  if (!isnum) {
+  if (l_unlikely(!isnum)) {
     interror(L, arg);
   }
   return d;
@@ -475,7 +475,7 @@ static void *resizebox (lua_State *L, int idx, size_t newsize) {
   lua_Alloc allocf = lua_getallocf(L, &ud);
   UBox *box = (UBox *)lua_touserdata(L, idx);
   void *temp = allocf(ud, box->box, box->bsize, newsize);
-  if (temp == NULL && newsize > 0) {  /* allocation error? */
+  if (l_unlikely(temp == NULL && newsize > 0)) {  /* allocation error? */
     lua_pushliteral(L, "not enough memory");
     lua_error(L);  /* raise a memory error */
   }
@@ -516,12 +516,21 @@ static void newbox (lua_State *L) {
 
 
 /*
+** Whenever buffer is accessed, slot 'idx' must either be a box (which
+** cannot be NULL) or it is a placeholder for the buffer.
+*/
+#define checkbufferlevel(B,idx)  \
+  lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL  \
+                            : lua_touserdata(B->L, idx) == (void*)B)
+
+
+/*
 ** Compute new size for buffer 'B', enough to accommodate extra 'sz'
 ** bytes.
 */
 static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
   size_t newsize = B->size * 2;  /* double buffer size */
-  if (MAX_SIZET - sz < B->n)  /* overflow in (B->n + sz)? */
+  if (l_unlikely(MAX_SIZET - sz < B->n))  /* overflow in (B->n + sz)? */
     return luaL_error(B->L, "buffer too large");
   if (newsize < B->n + sz)  /* double is not big enough? */
     newsize = B->n + sz;
@@ -531,10 +540,11 @@ static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
 
 /*
 ** Returns a pointer to a free area with at least 'sz' bytes in buffer
-** 'B'. 'boxidx' is the relative position in the stack where the
-** buffer's box is or should be.
+** 'B'. 'boxidx' is the relative position in the stack where is the
+** buffer's box or its placeholder.
 */
 static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
+  checkbufferlevel(B, boxidx);
   if (B->size - B->n >= sz)  /* enough space? */
     return B->b + B->n;
   else {
@@ -545,10 +555,9 @@ static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
     if (buffonstack(B))  /* buffer already has a box? */
       newbuff = (char *)resizebox(L, boxidx, newsize);  /* resize it */
     else {  /* no box yet */
-      lua_pushnil(L);  /* reserve slot for final result */
+      lua_remove(L, boxidx);  /* remove placeholder */
       newbox(L);  /* create a new box */
-      /* move box (and slot) to its intended position */
-      lua_rotate(L, boxidx - 1, 2);
+      lua_insert(L, boxidx);  /* move box to its intended position */
       lua_toclose(L, boxidx);
       newbuff = (char *)resizebox(L, boxidx, newsize);
       memcpy(newbuff, B->b, B->n * sizeof(char));  /* copy original content */
@@ -583,11 +592,11 @@ LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
 
 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
   lua_State *L = B->L;
+  checkbufferlevel(B, -1);
   lua_pushlstring(L, B->b, B->n);
-  if (buffonstack(B)) {
-    lua_copy(L, -1, -3);  /* move string to reserved slot */
-    lua_pop(L, 2);  /* pop string and box (closing the box) */
-  }
+  if (buffonstack(B))
+    lua_closeslot(L, -2);  /* close the box */
+  lua_remove(L, -2);  /* remove box or placeholder from the stack */
 }
 
 
@@ -622,6 +631,7 @@ LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
   B->b = B->init.b;
   B->n = 0;
   B->size = LUAL_BUFFERSIZE;
+  lua_pushlightuserdata(L, (void*)B);  /* push placeholder */
 }
 
 
@@ -639,10 +649,14 @@ LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
 ** =======================================================
 */
 
-/* index of free-list header */
-#define freelist	0
-
+/* index of free-list header (after the predefined values) */
+#define freelist	(LUA_RIDX_LAST + 1)
 
+/*
+** The previously freed references form a linked list:
+** t[freelist] is the index of a first free index, or zero if list is
+** empty; t[t[freelist]] is the index of the second element; etc.
+*/
 LUALIB_API int luaL_ref (lua_State *L, int t) {
   int ref;
   if (lua_isnil(L, -1)) {
@@ -650,9 +664,16 @@ LUALIB_API int luaL_ref (lua_State *L, int t) {
     return LUA_REFNIL;  /* 'nil' has a unique fixed reference */
   }
   t = lua_absindex(L, t);
-  lua_rawgeti(L, t, freelist);  /* get first free element */
-  ref = (int)lua_tointeger(L, -1);  /* ref = t[freelist] */
-  lua_pop(L, 1);  /* remove it from stack */
+  if (lua_rawgeti(L, t, freelist) == LUA_TNIL) {  /* first access? */
+    ref = 0;  /* list is empty */
+    lua_pushinteger(L, 0);  /* initialize as an empty list */
+    lua_rawseti(L, t, freelist);  /* ref = t[freelist] = 0 */
+  }
+  else {  /* already initialized */
+    lua_assert(lua_isinteger(L, -1));
+    ref = (int)lua_tointeger(L, -1);  /* ref = t[freelist] */
+  }
+  lua_pop(L, 1);  /* remove element from stack */
   if (ref != 0) {  /* any free element? */
     lua_rawgeti(L, t, ref);  /* remove it from list */
     lua_rawseti(L, t, freelist);  /* (t[freelist] = t[ref]) */
@@ -668,6 +689,7 @@ LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
   if (ref >= 0) {
     t = lua_absindex(L, t);
     lua_rawgeti(L, t, freelist);
+    lua_assert(lua_isinteger(L, -1));
     lua_rawseti(L, t, ref);  /* t[ref] = t[freelist] */
     lua_pushinteger(L, ref);
     lua_rawseti(L, t, freelist);  /* t[freelist] = ref */
@@ -851,7 +873,7 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
   int isnum;
   lua_len(L, idx);
   l = lua_tointegerx(L, -1, &isnum);
-  if (!isnum)
+  if (l_unlikely(!isnum))
     luaL_error(L, "object length is not an integer");
   lua_pop(L, 1);  /* remove object */
   return l;
@@ -859,6 +881,7 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
 
 
 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
+  idx = lua_absindex(L,idx);
   if (luaL_callmeta(L, idx, "__tostring")) {  /* metafield? */
     if (!lua_isstring(L, -1))
       luaL_error(L, "'__tostring' must return a string");
@@ -1064,7 +1087,7 @@ static void warnfon (void *ud, const char *message, int tocont) {
 
 LUALIB_API lua_State *luaL_newstate (void) {
   lua_State *L = lua_newstate(l_alloc, NULL);
-  if (L) {
+  if (l_likely(L)) {
     lua_atpanic(L, &panic);
     lua_setwarnf(L, warnfoff, L);  /* default is warnings off */
   }
diff --git a/contrib/lua/src/lauxlib.h b/contrib/lua/src/lauxlib.h
index 59fef6af132b..5b977e2a39f1 100644
--- a/contrib/lua/src/lauxlib.h
+++ b/contrib/lua/src/lauxlib.h
@@ -12,6 +12,7 @@
 #include <stddef.h>
 #include <stdio.h>
 
+#include "luaconf.h"
 #include "lua.h"
 
 
@@ -101,7 +102,7 @@ LUALIB_API lua_State *(luaL_newstate) (void);
 
 LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx);
 
-LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
+LUALIB_API void (luaL_addgsub) (luaL_Buffer *b, const char *s,
                                      const char *p, const char *r);
 LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s,
                                     const char *p, const char *r);
@@ -130,10 +131,10 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
   (luaL_checkversion(L), luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))
 
 #define luaL_argcheck(L, cond,arg,extramsg)	\
-		((void)((cond) || luaL_argerror(L, (arg), (extramsg))))
+	((void)(luai_likely(cond) || luaL_argerror(L, (arg), (extramsg))))
 
 #define luaL_argexpected(L,cond,arg,tname)	\
-		((void)((cond) || luaL_typeerror(L, (arg), (tname))))
+	((void)(luai_likely(cond) || luaL_typeerror(L, (arg), (tname))))
 
 #define luaL_checkstring(L,n)	(luaL_checklstring(L, (n), NULL))
 #define luaL_optstring(L,n,d)	(luaL_optlstring(L, (n), (d), NULL))
@@ -153,11 +154,35 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
 #define luaL_loadbuffer(L,s,sz,n)	luaL_loadbufferx(L,s,sz,n,NULL)
 
 
+/*
+** Perform arithmetic operations on lua_Integer values with wrap-around
+** semantics, as the Lua core does.
+*/
+#define luaL_intop(op,v1,v2)  \
+	((lua_Integer)((lua_Unsigned)(v1) op (lua_Unsigned)(v2)))
+
+
 /* push the value used to represent failure/error */
 #define luaL_pushfail(L)	lua_pushnil(L)
 
 
 /*
+** Internal assertions for in-house debugging
+*/
+#if !defined(lua_assert)
+
+#if defined LUAI_ASSERT
+  #include <assert.h>
+  #define lua_assert(c)		assert(c)
+#else
+  #define lua_assert(c)		((void)0)
+#endif
+
+#endif
+
+
+
+/*
 ** {======================================================
 ** Generic Buffer manipulation
 ** =======================================================
diff --git a/contrib/lua/src/lbaselib.c b/contrib/lua/src/lbaselib.c
index 747fd45a2fe5..1d60c9dede59 100644
--- a/contrib/lua/src/lbaselib.c
+++ b/contrib/lua/src/lbaselib.c
@@ -138,7 +138,7 @@ static int luaB_setmetatable (lua_State *L) {
   int t = lua_type(L, 2);
   luaL_checktype(L, 1, LUA_TTABLE);
   luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
-  if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
+  if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL))
     return luaL_error(L, "cannot change a protected metatable");
   lua_settop(L, 2);
   lua_setmetatable(L, 1);
@@ -182,11 +182,20 @@ static int luaB_rawset (lua_State *L) {
 
 
 static int pushmode (lua_State *L, int oldmode) {
-  lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental" : "generational");
+  if (oldmode == -1)
+    luaL_pushfail(L);  /* invalid call to 'lua_gc' */
+  else
+    lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"
+                                             : "generational");
   return 1;
 }
 
 
+/*
+** check whether call to 'lua_gc' was valid (not inside a finalizer)
+*/
+#define checkvalres(res) { if (res == -1) break; }
+
 static int luaB_collectgarbage (lua_State *L) {
   static const char *const opts[] = {"stop", "restart", "collect",
     "count", "step", "setpause", "setstepmul",
@@ -199,12 +208,14 @@ static int luaB_collectgarbage (lua_State *L) {
     case LUA_GCCOUNT: {
       int k = lua_gc(L, o);
       int b = lua_gc(L, LUA_GCCOUNTB);
+      checkvalres(k);
       lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
       return 1;
     }
     case LUA_GCSTEP: {
       int step = (int)luaL_optinteger(L, 2, 0);
       int res = lua_gc(L, o, step);
+      checkvalres(res);
       lua_pushboolean(L, res);
       return 1;
     }
@@ -212,11 +223,13 @@ static int luaB_collectgarbage (lua_State *L) {
     case LUA_GCSETSTEPMUL: {
       int p = (int)luaL_optinteger(L, 2, 0);
       int previous = lua_gc(L, o, p);
+      checkvalres(previous);
       lua_pushinteger(L, previous);
       return 1;
     }
     case LUA_GCISRUNNING: {
       int res = lua_gc(L, o);
+      checkvalres(res);
       lua_pushboolean(L, res);
       return 1;
     }
@@ -233,10 +246,13 @@ static int luaB_collectgarbage (lua_State *L) {
     }
     default: {
       int res = lua_gc(L, o);
+      checkvalres(res);
       lua_pushinteger(L, res);
       return 1;
     }
   }
+  luaL_pushfail(L);  /* invalid call (inside a finalizer) */
+  return 1;
 }
 
 
@@ -260,6 +276,11 @@ static int luaB_next (lua_State *L) {
 }
 
 
+static int pairscont (lua_State *L, int status, lua_KContext k) {
+  (void)L; (void)status; (void)k;  /* unused */
+  return 3;
+}
+
 static int luaB_pairs (lua_State *L) {
   luaL_checkany(L, 1);
   if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) {  /* no metamethod? */
@@ -269,7 +290,7 @@ static int luaB_pairs (lua_State *L) {
   }
   else {
     lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
-    lua_call(L, 1, 3);  /* get 3 values from metamethod */
+    lua_callk(L, 1, 3, 0, pairscont);  /* get 3 values from metamethod */
   }
   return 3;
 }
@@ -279,7 +300,8 @@ static int luaB_pairs (lua_State *L) {
 ** Traversal function for 'ipairs'
 */
 static int ipairsaux (lua_State *L) {
-  lua_Integer i = luaL_checkinteger(L, 2) + 1;
+  lua_Integer i = luaL_checkinteger(L, 2);
+  i = luaL_intop(+, i, 1);
   lua_pushinteger(L, i);
   return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
 }
@@ -299,7 +321,7 @@ static int luaB_ipairs (lua_State *L) {
 
 
 static int load_aux (lua_State *L, int status, int envidx) {
-  if (status == LUA_OK) {
+  if (l_likely(status == LUA_OK)) {
     if (envidx != 0) {  /* 'env' parameter? */
       lua_pushvalue(L, envidx);  /* environment for loaded function */
       if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
@@ -355,7 +377,7 @@ static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
     *size = 0;
     return NULL;
   }
-  else if (!lua_isstring(L, -1))
+  else if (l_unlikely(!lua_isstring(L, -1)))
     luaL_error(L, "reader function must return a string");
   lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
   return lua_tolstring(L, RESERVEDSLOT, size);
@@ -393,7 +415,7 @@ static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
 static int luaB_dofile (lua_State *L) {
   const char *fname = luaL_optstring(L, 1, NULL);
   lua_settop(L, 1);
-  if (luaL_loadfile(L, fname) != LUA_OK)
+  if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))
     return lua_error(L);
   lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
   return dofilecont(L, 0, 0);
@@ -401,7 +423,7 @@ static int luaB_dofile (lua_State *L) {
 
 
 static int luaB_assert (lua_State *L) {
-  if (lua_toboolean(L, 1))  /* condition is true? */
+  if (l_likely(lua_toboolean(L, 1)))  /* condition is true? */
     return lua_gettop(L);  /* return all arguments */
   else {  /* error */
     luaL_checkany(L, 1);  /* there must be a condition */
@@ -437,7 +459,7 @@ static int luaB_select (lua_State *L) {
 ** ignored).
 */
 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
-  if (status != LUA_OK && status != LUA_YIELD) {  /* error? */
+  if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) {  /* error? */
     lua_pushboolean(L, 0);  /* first result (false) */
     lua_pushvalue(L, -2);  /* error message */
     return 2;  /* return false, msg */
diff --git a/contrib/lua/src/lcode.c b/contrib/lua/src/lcode.c
index 14d41f1a7ef4..97e3c72857a5 100644
--- a/contrib/lua/src/lcode.c
+++ b/contrib/lua/src/lcode.c
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <float.h>
 #include <limits.h>
 #include <math.h>
 #include <stdlib.h>
@@ -314,15 +315,6 @@ void luaK_patchtohere (FuncState *fs, int list) {
 }
 
 
-/*
-** MAXimum number of successive Instructions WiTHout ABSolute line
-** information.
-*/
-#if !defined(MAXIWTHABS)
-#define MAXIWTHABS	120
-#endif
-
-
 /* limit for difference between lines in relative line info. */
 #define LIMLINEDIFF	0x80
 
@@ -337,13 +329,13 @@ void luaK_patchtohere (FuncState *fs, int list) {
 static void savelineinfo (FuncState *fs, Proto *f, int line) {
   int linedif = line - fs->previousline;
   int pc = fs->pc - 1;  /* last instruction coded */
-  if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ > MAXIWTHABS) {
+  if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ >= MAXIWTHABS) {
     luaM_growvector(fs->ls->L, f->abslineinfo, fs->nabslineinfo,
                     f->sizeabslineinfo, AbsLineInfo, MAX_INT, "lines");
     f->abslineinfo[fs->nabslineinfo].pc = pc;
     f->abslineinfo[fs->nabslineinfo++].line = line;
     linedif = ABSLINEINFO;  /* signal that there is absolute information */
-    fs->iwthabs = 0;  /* restart counter */
+    fs->iwthabs = 1;  /* restart counter */
   }
   luaM_growvector(fs->ls->L, f->lineinfo, pc, f->sizelineinfo, ls_byte,
                   MAX_INT, "opcodes");
@@ -545,11 +537,14 @@ static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) {
 ** and try to reuse constants. Because some values should not be used
 ** as keys (nil cannot be a key, integer keys can collapse with float
 ** keys), the caller must provide a useful 'key' for indexing the cache.
+** Note that all functions share the same table, so entering or exiting
+** a function can make some indices wrong.
 */
 static int addk (FuncState *fs, TValue *key, TValue *v) {
+  TValue val;
   lua_State *L = fs->ls->L;
   Proto *f = fs->f;
-  TValue *idx = luaH_set(L, fs->ls->h, key);  /* index scanner table */
+  const TValue *idx = luaH_get(fs->ls->h, key);  /* query scanner table */
   int k, oldsize;
   if (ttisinteger(idx)) {  /* is there an index there? */
     k = cast_int(ivalue(idx));
@@ -563,7 +558,8 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
   k = fs->nk;
   /* numerical value does not need GC barrier;
      table has no metatable, so it does not need to invalidate cache */
-  setivalue(idx, k);
+  setivalue(&val, k);
+  luaH_finishset(L, fs->ls->h, key, idx, &val);
   luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");
   while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
   setobj(L, &f->k[k], v);
@@ -585,24 +581,48 @@ static int stringK (FuncState *fs, TString *s) {
 
 /*
 ** Add an integer to list of constants and return its index.
-** Integers use userdata as keys to avoid collision with floats with
-** same value; conversion to 'void*' is used only for hashing, so there
-** are no "precision" problems.
 */
 static int luaK_intK (FuncState *fs, lua_Integer n) {
-  TValue k, o;
-  setpvalue(&k, cast_voidp(cast_sizet(n)));
+  TValue o;
   setivalue(&o, n);
-  return addk(fs, &k, &o);
+  return addk(fs, &o, &o);  /* use integer itself as key */
 }
 
 /*
-** Add a float to list of constants and return its index.
+** Add a float to list of constants and return its index. Floats
+** with integral values need a different key, to avoid collision
+** with actual integers. To that, we add to the number its smaller
+** power-of-two fraction that is still significant in its scale.
+** For doubles, that would be 1/2^52.
+** (This method is not bulletproof: there may be another float
+** with that value, and for floats larger than 2^53 the result is
+** still an integer. At worst, this only wastes an entry with
+** a duplicate.)
 */
 static int luaK_numberK (FuncState *fs, lua_Number r) {
   TValue o;
+  lua_Integer ik;
   setfltvalue(&o, r);
+#ifndef LUA_AVOID_FLOAT
+  if (!luaV_flttointeger(r, &ik, F2Ieq))  /* not an integral value? */
+    return addk(fs, &o, &o);  /* use number itself as key */
+  else {  /* must build an alternative key */
+    const int nbm = l_floatatt(MANT_DIG);
+    const lua_Number q = l_mathop(ldexp)(l_mathop(1.0), -nbm + 1);
+    const lua_Number k = (ik == 0) ? q : r + r*q;  /* new key */
+    TValue kv;
+    setfltvalue(&kv, k);
+    /* result is not an integral value, unless value is too large */
+    lua_assert(!luaV_flttointeger(k, &ik, F2Ieq) ||
+                l_mathop(fabs)(r) >= l_mathop(1e6));
+    return addk(fs, &kv, &o);
+  }
+#else
+  /*
+  ** When we're avoiding floats, allow any collision since floats are ints.
+  */
   return addk(fs, &o, &o);  /* use number itself as key */
+#endif
 }
 
 
@@ -763,7 +783,7 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
       break;
     }
     case VLOCAL: {  /* already in a register */
-      e->u.info = e->u.var.sidx;
+      e->u.info = e->u.var.ridx;
       e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
@@ -1036,7 +1056,7 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
   switch (var->k) {
     case VLOCAL: {
       freeexp(fs, ex);
-      exp2reg(fs, ex, var->u.var.sidx);  /* compute 'ex' into proper place */
+      exp2reg(fs, ex, var->u.var.ridx);  /* compute 'ex' into proper place */
       return;
     }
     case VUPVAL: {
@@ -1276,7 +1296,7 @@ void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
   }
   else {
     /* register index of the table */
-    t->u.ind.t = (t->k == VLOCAL) ? t->u.var.sidx: t->u.info;
+    t->u.ind.t = (t->k == VLOCAL) ? t->u.var.ridx: t->u.info;
     if (isKstr(fs, k)) {
       t->u.ind.idx = k->u.info;  /* literal string */
       t->k = VINDEXSTR;
@@ -1303,7 +1323,8 @@ static int validop (int op, TValue *v1, TValue *v2) {
     case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
     case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: {  /* conversion errors */
       lua_Integer i;
-      return (tointegerns(v1, &i) && tointegerns(v2, &i));
+      return (luaV_tointegerns(v1, &i, LUA_FLOORN2I) &&
+              luaV_tointegerns(v2, &i, LUA_FLOORN2I));
     }
     case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD:  /* division by 0 */
       return (nvalue(v2) != 0);
diff --git a/contrib/lua/src/lcorolib.c b/contrib/lua/src/lcorolib.c
index c165031d280a..785a1e81aa0a 100644
--- a/contrib/lua/src/lcorolib.c
+++ b/contrib/lua/src/lcorolib.c
@@ -31,14 +31,14 @@ static lua_State *getco (lua_State *L) {
 */
 static int auxresume (lua_State *L, lua_State *co, int narg) {
   int status, nres;
-  if (!lua_checkstack(co, narg)) {
+  if (l_unlikely(!lua_checkstack(co, narg))) {
     lua_pushliteral(L, "too many arguments to resume");
     return -1;  /* error flag */
   }
   lua_xmove(L, co, narg);
   status = lua_resume(co, L, narg, &nres);
-  if (status == LUA_OK || status == LUA_YIELD) {
-    if (!lua_checkstack(L, nres + 1)) {
+  if (l_likely(status == LUA_OK || status == LUA_YIELD)) {
+    if (l_unlikely(!lua_checkstack(L, nres + 1))) {
       lua_pop(co, nres);  /* remove results anyway */
       lua_pushliteral(L, "too many results to resume");
       return -1;  /* error flag */
@@ -57,7 +57,7 @@ static int luaB_coresume (lua_State *L) {
   lua_State *co = getco(L);
   int r;
   r = auxresume(L, co, lua_gettop(L) - 1);
-  if (r < 0) {
+  if (l_unlikely(r < 0)) {
     lua_pushboolean(L, 0);
     lua_insert(L, -2);
     return 2;  /* return false + error message */
@@ -73,10 +73,13 @@ static int luaB_coresume (lua_State *L) {
 static int luaB_auxwrap (lua_State *L) {
   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
   int r = auxresume(L, co, lua_gettop(L));
-  if (r < 0) {  /* error? */
+  if (l_unlikely(r < 0)) {  /* error? */
     int stat = lua_status(co);
-    if (stat != LUA_OK && stat != LUA_YIELD)  /* error in the coroutine? */
-      lua_resetthread(co);  /* close its tbc variables */
+    if (stat != LUA_OK && stat != LUA_YIELD) {  /* error in the coroutine? */
+      stat = lua_resetthread(co);  /* close its tbc variables */
+      lua_assert(stat != LUA_OK);
+      lua_xmove(co, L, 1);  /* move error message to the caller */
+    }
     if (stat != LUA_ERRMEM &&  /* not a memory error and ... */
         lua_type(L, -1) == LUA_TSTRING) {  /* ... error object is a string? */
       luaL_where(L, 1);  /* add extra info, if available */
@@ -176,7 +179,7 @@ static int luaB_close (lua_State *L) {
       }
       else {
         lua_pushboolean(L, 0);
-        lua_xmove(co, L, 1);  /* copy error message */
+        lua_xmove(co, L, 1);  /* move error message */
         return 2;
       }
     }
diff --git a/contrib/lua/src/ldblib.c b/contrib/lua/src/ldblib.c
index 5a326adedb02..6dcbaa9824ba 100644
--- a/contrib/lua/src/ldblib.c
+++ b/contrib/lua/src/ldblib.c
@@ -33,7 +33,7 @@ static const char *const HOOKKEY = "_HOOKKEY";
 ** checked.
 */
 static void checkstack (lua_State *L, lua_State *L1, int n) {
-  if (L != L1 && !lua_checkstack(L1, n))
+  if (l_unlikely(L != L1 && !lua_checkstack(L1, n)))
     luaL_error(L, "stack overflow");
 }
 
@@ -152,6 +152,7 @@ static int db_getinfo (lua_State *L) {
   lua_State *L1 = getthread(L, &arg);
   const char *options = luaL_optstring(L, arg+2, "flnSrtu");
   checkstack(L, L1, 3);
+  luaL_argcheck(L, options[0] != '>', arg + 2, "invalid option '>'");
   if (lua_isfunction(L, arg + 1)) {  /* info about a function? */
     options = lua_pushfstring(L, ">%s", options);  /* add '>' to 'options' */
     lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */
@@ -212,7 +213,7 @@ static int db_getlocal (lua_State *L) {
     lua_Debug ar;
     const char *name;
     int level = (int)luaL_checkinteger(L, arg + 1);
-    if (!lua_getstack(L1, level, &ar))  /* out of range? */
+    if (l_unlikely(!lua_getstack(L1, level, &ar)))  /* out of range? */
       return luaL_argerror(L, arg+1, "level out of range");
     checkstack(L, L1, 1);
     name = lua_getlocal(L1, &ar, nvar);
@@ -237,7 +238,7 @@ static int db_setlocal (lua_State *L) {
   lua_Debug ar;
   int level = (int)luaL_checkinteger(L, arg + 1);
   int nvar = (int)luaL_checkinteger(L, arg + 2);
-  if (!lua_getstack(L1, level, &ar))  /* out of range? */
+  if (l_unlikely(!lua_getstack(L1, level, &ar)))  /* out of range? */
     return luaL_argerror(L, arg+1, "level out of range");
   luaL_checkany(L, arg+3);
   lua_settop(L, arg+3);
@@ -377,7 +378,7 @@ static int db_sethook (lua_State *L) {
   }
   if (!luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)) {
     /* table just created; initialize it */
-    lua_pushstring(L, "k");
+    lua_pushliteral(L, "k");
     lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */
     lua_pushvalue(L, -1);
     lua_setmetatable(L, -2);  /* metatable(hooktable) = hooktable */
@@ -420,7 +421,7 @@ static int db_debug (lua_State *L) {
   for (;;) {
     char buffer[250];
     lua_writestringerror("%s", "lua_debug> ");
-    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
+    if (fgets(buffer, sizeof(buffer), stdin) == NULL ||
         strcmp(buffer, "cont\n") == 0)
       return 0;
     if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
diff --git a/contrib/lua/src/ldebug.c b/contrib/lua/src/ldebug.c
index 8cb00e51a100..a716d95e22f6 100644
--- a/contrib/lua/src/ldebug.c
+++ b/contrib/lua/src/ldebug.c
@@ -33,11 +33,9 @@
 
 #define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_VCCL)
 
-/* inverse of 'pcRel' */
-#define invpcRel(pc, p)		((p)->code + (pc) + 1)
 
-static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
-                                    const char **name);
+static const char *funcnamefromcall (lua_State *L, CallInfo *ci,
+                                                   const char **name);
 
 
 static int currentpc (CallInfo *ci) {
@@ -48,10 +46,16 @@ static int currentpc (CallInfo *ci) {
 
 /*
 ** Get a "base line" to find the line corresponding to an instruction.
-** For that, search the array of absolute line info for the largest saved
-** instruction smaller or equal to the wanted instruction. A special
-** case is when there is no absolute info or the instruction is before
-** the first absolute one.
+** Base lines are regularly placed at MAXIWTHABS intervals, so usually
+** an integer division gets the right place. When the source file has
+** large sequences of empty/comment lines, it may need extra entries,
+** so the original estimate needs a correction.
+** If the original estimate is -1, the initial 'if' ensures that the
+** 'while' will run at least once.
+** The assertion that the estimate is a lower bound for the correct base
+** is valid as long as the debug info has been generated with the same
+** value for MAXIWTHABS or smaller. (Previous releases use a little
+** smaller value.)
 */
 static int getbaseline (const Proto *f, int pc, int *basepc) {
   if (f->sizeabslineinfo == 0 || pc < f->abslineinfo[0].pc) {
@@ -59,20 +63,12 @@ static int getbaseline (const Proto *f, int pc, int *basepc) {
     return f->linedefined;
   }
   else {
-    unsigned int i;
-    if (pc >= f->abslineinfo[f->sizeabslineinfo - 1].pc)
-      i = f->sizeabslineinfo - 1;  /* instruction is after last saved one */
-    else {  /* binary search */
-      unsigned int j = f->sizeabslineinfo - 1;  /* pc < anchorlines[j] */
-      i = 0;  /* abslineinfo[i] <= pc */
-      while (i < j - 1) {
-        unsigned int m = (j + i) / 2;
-        if (pc >= f->abslineinfo[m].pc)
-          i = m;
-        else
-          j = m;
-      }
-    }
+    int i = cast_uint(pc) / MAXIWTHABS - 1;  /* get an estimate */
+    /* estimate must be a lower bound of the correct base */
+    lua_assert(i < 0 ||
+              (i < f->sizeabslineinfo && f->abslineinfo[i].pc <= pc));
+    while (i + 1 < f->sizeabslineinfo && pc >= f->abslineinfo[i + 1].pc)
+      i++;  /* low estimate; adjust it */
     *basepc = f->abslineinfo[i].pc;
     return f->abslineinfo[i].line;
   }
@@ -305,8 +301,15 @@ static void collectvalidlines (lua_State *L, Closure *f) {
     sethvalue2s(L, L->top, t);  /* push it on stack */
     api_incr_top(L);
     setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
-    for (i = 0; i < p->sizelineinfo; i++) {  /* for all lines with code */
-      currentline = nextline(p, currentline, i);
+    if (!p->is_vararg)  /* regular function? */
+      i = 0;  /* consider all instructions */
+    else {  /* vararg function */
+      lua_assert(GET_OPCODE(p->code[0]) == OP_VARARGPREP);
+      currentline = nextline(p, currentline, 0);
+      i = 1;  /* skip first instruction (OP_VARARGPREP) */
+    }
+    for (; i < p->sizelineinfo; i++) {  /* for each instruction */
+      currentline = nextline(p, currentline, i);  /* get its line */
       luaH_setint(L, t, currentline, &v);  /* table[line] = true */
     }
   }
@@ -314,15 +317,9 @@ static void collectvalidlines (lua_State *L, Closure *f) {
 
 
 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
-  if (ci == NULL)  /* no 'ci'? */
-    return NULL;  /* no info */
-  else if (ci->callstatus & CIST_FIN) {  /* is this a finalizer? */
-    *name = "__gc";
-    return "metamethod";  /* report it as such */
-  }
-  /* calling function is a known Lua function? */
-  else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
-    return funcnamefromcode(L, ci->previous, name);
+  /* calling function is a known function? */
+  if (ci != NULL && !(ci->callstatus & CIST_TAIL))
+    return funcnamefromcall(L, ci->previous, name);
   else return NULL;  /* no way to find a name */
 }
 
@@ -594,16 +591,10 @@ static const char *getobjname (const Proto *p, int lastpc, int reg,
 ** Returns what the name is (e.g., "for iterator", "method",
 ** "metamethod") and sets '*name' to point to the name.
 */
-static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
-                                     const char **name) {
+static const char *funcnamefromcode (lua_State *L, const Proto *p,
+                                     int pc, const char **name) {
   TMS tm = (TMS)0;  /* (initial value avoids warnings) */
-  const Proto *p = ci_func(ci)->p;  /* calling function */
-  int pc = currentpc(ci);  /* calling instruction index */
   Instruction i = p->code[pc];  /* calling instruction */
-  if (ci->callstatus & CIST_HOOKED) {  /* was it called inside a hook? */
-    *name = "?";
-    return "hook";
-  }
   switch (GET_OPCODE(i)) {
     case OP_CALL:
     case OP_TAILCALL:
@@ -629,12 +620,10 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
     case OP_LEN: tm = TM_LEN; break;
     case OP_CONCAT: tm = TM_CONCAT; break;
     case OP_EQ: tm = TM_EQ; break;
-    case OP_LT: case OP_LE: case OP_LTI: case OP_LEI:
-      *name = "order";  /* '<=' can call '__lt', etc. */
-      return "metamethod";
-    case OP_CLOSE: case OP_RETURN:
-      *name = "close";
-      return "metamethod";
+    /* no cases for OP_EQI and OP_EQK, as they don't call metamethods */
+    case OP_LT: case OP_LTI: case OP_GTI: tm = TM_LT; break;
+    case OP_LE: case OP_LEI: case OP_GEI: tm = TM_LE; break;
+    case OP_CLOSE: case OP_RETURN: tm = TM_CLOSE; break;
     default:
       return NULL;  /* cannot find a reasonable name */
   }
@@ -642,19 +631,43 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
   return "metamethod";
 }
 
+
+/*
+** Try to find a name for a function based on how it was called.
+*/
+static const char *funcnamefromcall (lua_State *L, CallInfo *ci,
+                                                   const char **name) {
+  if (ci->callstatus & CIST_HOOKED) {  /* was it called inside a hook? */
+    *name = "?";
+    return "hook";
+  }
+  else if (ci->callstatus & CIST_FIN) {  /* was it called as a finalizer? */
+    *name = "__gc";
+    return "metamethod";  /* report it as such */
+  }
+  else if (isLua(ci))
+    return funcnamefromcode(L, ci_func(ci)->p, currentpc(ci), name);
+  else
+    return NULL;
+}
+
 /* }====================================================== */
 
 
 
 /*
-** The subtraction of two potentially unrelated pointers is
-** not ISO C, but it should not crash a program; the subsequent
-** checks are ISO C and ensure a correct result.
+** Check whether pointer 'o' points to some value in the stack
+** frame of the current function. Because 'o' may not point to a
+** value in this stack, we cannot compare it with the region
+** boundaries (undefined behaviour in ISO C).
 */
 static int isinstack (CallInfo *ci, const TValue *o) {
-  StkId base = ci->func + 1;
-  ptrdiff_t i = cast(StkId, o) - base;
-  return (0 <= i && i < (ci->top - base) && s2v(base + i) == o);
+  StkId pos;
+  for (pos = ci->func + 1; pos < ci->top; pos++) {
+    if (o == s2v(pos))
+      return 1;
+  }
+  return 0;  /* not found */
 }
 
 
@@ -677,9 +690,21 @@ static const char *getupvalname (CallInfo *ci, const TValue *o,
 }
 
 
+static const char *formatvarinfo (lua_State *L, const char *kind,
+                                                const char *name) {
+  if (kind == NULL)
+    return "";  /* no information */
+  else
+    return luaO_pushfstring(L, " (%s '%s')", kind, name);
+}
+
+/*
+** Build a string with a "description" for the value 'o', such as
+** "variable 'x'" or "upvalue 'y'".
+*/
 static const char *varinfo (lua_State *L, const TValue *o) {
-  const char *name = NULL;  /* to avoid warnings */
   CallInfo *ci = L->ci;
+  const char *name = NULL;  /* to avoid warnings */
   const char *kind = NULL;
   if (isLua(ci)) {
     kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
@@ -687,13 +712,40 @@ static const char *varinfo (lua_State *L, const TValue *o) {
       kind = getobjname(ci_func(ci)->p, currentpc(ci),
                         cast_int(cast(StkId, o) - (ci->func + 1)), &name);
   }
-  return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
+  return formatvarinfo(L, kind, name);
 }
 
 
-l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
+/*
+** Raise a type error
+*/
+static l_noret typeerror (lua_State *L, const TValue *o, const char *op,
+                          const char *extra) {
   const char *t = luaT_objtypename(L, o);
-  luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
+  luaG_runerror(L, "attempt to %s a %s value%s", op, t, extra);
+}
+
+
+/*
+** Raise a type error with "standard" information about the faulty
+** object 'o' (using 'varinfo').
+*/
+l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
+  typeerror(L, o, op, varinfo(L, o));
+}
+
+
+/*
+** Raise an error for calling a non-callable object. Try to find a name
+** for the object based on how it was called ('funcnamefromcall'); if it
+** cannot get a name there, try 'varinfo'.
+*/
+l_noret luaG_callerror (lua_State *L, const TValue *o) {
+  CallInfo *ci = L->ci;
+  const char *name = NULL;  /* to avoid warnings */
+  const char *kind = funcnamefromcall(L, ci, &name);
+  const char *extra = kind ? formatvarinfo(L, kind, name) : varinfo(L, o);
+  typeerror(L, o, "call", extra);
 }
 
 
@@ -722,7 +774,7 @@ l_noret luaG_opinterror (lua_State *L, const TValue *p1,
 */
 l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
   lua_Integer temp;
-  if (!tointegerns(p1, &temp))
+  if (!luaV_tointegerns(p1, &temp, LUA_FLOORN2I))
     p2 = p1;
   luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
 }
@@ -780,16 +832,30 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
 
 /*
 ** Check whether new instruction 'newpc' is in a different line from
-** previous instruction 'oldpc'.
+** previous instruction 'oldpc'. More often than not, 'newpc' is only
+** one or a few instructions after 'oldpc' (it must be after, see
+** caller), so try to avoid calling 'luaG_getfuncline'. If they are
+** too far apart, there is a good chance of a ABSLINEINFO in the way,
+** so it goes directly to 'luaG_getfuncline'.
 */
 static int changedline (const Proto *p, int oldpc, int newpc) {
   if (p->lineinfo == NULL)  /* no debug information? */
     return 0;
-  while (oldpc++ < newpc) {
-    if (p->lineinfo[oldpc] != 0)
-      return (luaG_getfuncline(p, oldpc - 1) != luaG_getfuncline(p, newpc));
+  if (newpc - oldpc < MAXIWTHABS / 2) {  /* not too far apart? */
+    int delta = 0;  /* line diference */
+    int pc = oldpc;
+    for (;;) {
+      int lineinfo = p->lineinfo[++pc];
+      if (lineinfo == ABSLINEINFO)
+        break;  /* cannot compute delta; fall through */
+      delta += lineinfo;
+      if (pc == newpc)
+        return (delta != 0);  /* delta computed successfully */
+    }
   }
-  return 0;  /* no line changes between positions */
+  /* either instructions are too far apart or there is an absolute line
+     info in the way; compute line difference explicitly */
+  return (luaG_getfuncline(p, oldpc) != luaG_getfuncline(p, newpc));
 }
 
 
@@ -797,20 +863,19 @@ static int changedline (const Proto *p, int oldpc, int newpc) {
 ** Traces the execution of a Lua function. Called before the execution
 ** of each opcode, when debug is on. 'L->oldpc' stores the last
 ** instruction traced, to detect line changes. When entering a new
-** function, 'npci' will be zero and will test as a new line without
-** the need for 'oldpc'; so, 'oldpc' does not need to be initialized
-** before. Some exceptional conditions may return to a function without
-** updating 'oldpc'. In that case, 'oldpc' may be invalid; if so, it is
-** reset to zero.  (A wrong but valid 'oldpc' at most causes an extra
-** call to a line hook.)
+** function, 'npci' will be zero and will test as a new line whatever
+** the value of 'oldpc'.  Some exceptional conditions may return to
+** a function without setting 'oldpc'. In that case, 'oldpc' may be
+** invalid; if so, use zero as a valid value. (A wrong but valid 'oldpc'
+** at most causes an extra call to a line hook.)
+** This function is not "Protected" when called, so it should correct
+** 'L->top' before calling anything that can run the GC.
 */
 int luaG_traceexec (lua_State *L, const Instruction *pc) {
   CallInfo *ci = L->ci;
   lu_byte mask = L->hookmask;
   const Proto *p = ci_func(ci)->p;
   int counthook;
-  /* 'L->oldpc' may be invalid; reset it in this case */
-  int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0;
   if (!(mask & (LUA_MASKLINE | LUA_MASKCOUNT))) {  /* no hooks? */
     ci->u.l.trap = 0;  /* don't need to stop again */
     return 0;  /* turn off 'trap' */
@@ -826,15 +891,16 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) {
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
     return 1;  /* do not call hook again (VM yielded, so it did not move) */
   }
-  if (!isIT(*(ci->u.l.savedpc - 1)))
-    L->top = ci->top;  /* prepare top */
+  if (!isIT(*(ci->u.l.savedpc - 1)))  /* top not being used? */
+    L->top = ci->top;  /* correct top */
   if (counthook)
     luaD_hook(L, LUA_HOOKCOUNT, -1, 0, 0);  /* call count hook */
   if (mask & LUA_MASKLINE) {
+    /* 'L->oldpc' may be invalid; use zero in this case */
+    int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0;
     int npci = pcRel(pc, p);
-    if (npci == 0 ||  /* call linehook when enter a new function, */
-        pc <= invpcRel(oldpc, p) ||  /* when jump back (loop), or when */
-        changedline(p, oldpc, npci)) {  /* enter new line */
+    if (npci <= oldpc ||  /* call hook when jump back (loop), */
+        changedline(p, oldpc, npci)) {  /* or when enter new line */
       int newline = luaG_getfuncline(p, npci);
       luaD_hook(L, LUA_HOOKLINE, newline, 0, 0);  /* call line hook */
     }
diff --git a/contrib/lua/src/ldebug.h b/contrib/lua/src/ldebug.h
index a0a584862e96..974960e99da0 100644
--- a/contrib/lua/src/ldebug.h
+++ b/contrib/lua/src/ldebug.h
@@ -26,11 +26,22 @@
 */
 #define ABSLINEINFO	(-0x80)
 
+
+/*
+** MAXimum number of successive Instructions WiTHout ABSolute line
+** information. (A power of two allows fast divisions.)
+*/
+#if !defined(MAXIWTHABS)
+#define MAXIWTHABS	128
+#endif
+
+
 LUAI_FUNC int luaG_getfuncline (const Proto *f, int pc);
 LUAI_FUNC const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n,
                                                     StkId *pos);
 LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o,
                                                 const char *opname);
+LUAI_FUNC l_noret luaG_callerror (lua_State *L, const TValue *o);
 LUAI_FUNC l_noret luaG_forerror (lua_State *L, const TValue *o,
                                                const char *what);
 LUAI_FUNC l_noret luaG_concaterror (lua_State *L, const TValue *p1,
diff --git a/contrib/lua/src/ldo.c b/contrib/lua/src/ldo.c
index 4b55c31c2d8c..a48e35f9dba9 100644
--- a/contrib/lua/src/ldo.c
+++ b/contrib/lua/src/ldo.c
@@ -98,11 +98,12 @@ void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
       setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
       break;
     }
-    case CLOSEPROTECT: {
+    case LUA_OK: {  /* special case only for closing upvalues */
       setnilvalue(s2v(oldtop));  /* no error message */
       break;
     }
     default: {
+      lua_assert(errorstatus(errcode));  /* real error */
       setobjs2s(L, oldtop, L->top - 1);  /* error message on current top */
       break;
     }
@@ -118,17 +119,13 @@ l_noret luaD_throw (lua_State *L, int errcode) {
   }
   else {  /* thread has no error handler */
     global_State *g = G(L);
-    errcode = luaF_close(L, L->stack, errcode);  /* close all upvalues */
-    L->status = cast_byte(errcode);  /* mark it as dead */
+    errcode = luaE_resetthread(L, errcode);  /* close all upvalues */
     if (g->mainthread->errorJmp) {  /* main thread has a handler? */
       setobjs2s(L, g->mainthread->top++, L->top - 1);  /* copy error obj. */
       luaD_throw(g->mainthread, errcode);  /* re-throw in main thread */
     }
     else {  /* no handler at all; abort */
       if (g->panic) {  /* panic function? */
-        luaD_seterrorobj(L, errcode, L->top);  /* assume EXTRA_STACK */
-        if (L->ci->top < L->top)
-          L->ci->top = L->top;  /* pushing msg. can break this invariant */
         lua_unlock(L);
         g->panic(L);  /* call panic function (last chance to jump out) */
       }
@@ -163,9 +160,8 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
 static void correctstack (lua_State *L, StkId oldstack, StkId newstack) {
   CallInfo *ci;
   UpVal *up;
-  if (oldstack == newstack)
-    return;  /* stack address did not change */
   L->top = (L->top - oldstack) + newstack;
+  L->tbclist = (L->tbclist - oldstack) + newstack;
   for (up = L->openupval; up != NULL; up = up->u.open.next)
     up->v = s2v((uplevel(up) - oldstack) + newstack);
   for (ci = L->ci; ci != NULL; ci = ci->previous) {
@@ -181,19 +177,35 @@ static void correctstack (lua_State *L, StkId oldstack, StkId newstack) {
 #define ERRORSTACKSIZE	(LUAI_MAXSTACK + 200)
 
 
+/*
+** Reallocate the stack to a new size, correcting all pointers into
+** it. (There are pointers to a stack from its upvalues, from its list
+** of call infos, plus a few individual pointers.) The reallocation is
+** done in two steps (allocation + free) because the correction must be
+** done while both addresses (the old stack and the new one) are valid.
+** (In ISO C, any pointer use after the pointer has been deallocated is
+** undefined behavior.)
+** In case of allocation error, raise an error or return false according
+** to 'raiseerror'.
+*/
 int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
-  int lim = stacksize(L);
-  StkId newstack = luaM_reallocvector(L, L->stack,
-                      lim + EXTRA_STACK, newsize + EXTRA_STACK, StackValue);
+  int oldsize = stacksize(L);
+  int i;
+  StkId newstack = luaM_reallocvector(L, NULL, 0,
+                                      newsize + EXTRA_STACK, StackValue);
   lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
-  if (unlikely(newstack == NULL)) {  /* reallocation failed? */
+  if (l_unlikely(newstack == NULL)) {  /* reallocation failed? */
     if (raiseerror)
       luaM_error(L);
     else return 0;  /* do not raise an error */
   }
-  for (; lim < newsize; lim++)
-    setnilvalue(s2v(newstack + lim + EXTRA_STACK)); /* erase new segment */
+  /* number of elements to be copied to the new stack */
+  i = ((oldsize <= newsize) ? oldsize : newsize) + EXTRA_STACK;
+  memcpy(newstack, L->stack, i * sizeof(StackValue));
+  for (; i < newsize + EXTRA_STACK; i++)
+    setnilvalue(s2v(newstack + i)); /* erase new segment */
   correctstack(L, L->stack, newstack);
+  luaM_freearray(L, L->stack, oldsize + EXTRA_STACK);
   L->stack = newstack;
   L->stack_last = L->stack + newsize;
   return 1;
@@ -206,7 +218,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
 */
 int luaD_growstack (lua_State *L, int n, int raiseerror) {
   int size = stacksize(L);
-  if (unlikely(size > LUAI_MAXSTACK)) {
+  if (l_unlikely(size > LUAI_MAXSTACK)) {
     /* if stack is larger than maximum, thread is already using the
        extra space reserved for errors, that is, thread is handling
        a stack error; cannot grow further than that. */
@@ -222,7 +234,7 @@ int luaD_growstack (lua_State *L, int n, int raiseerror) {
       newsize = LUAI_MAXSTACK;
     if (newsize < needed)  /* but must respect what was asked for */
       newsize = needed;
-    if (likely(newsize <= LUAI_MAXSTACK))
+    if (l_likely(newsize <= LUAI_MAXSTACK))
       return luaD_reallocstack(L, newsize, raiseerror);
     else {  /* stack overflow */
       /* add extra size to be able to handle the error message */
@@ -297,8 +309,8 @@ void luaD_hook (lua_State *L, int event, int line,
   if (hook && L->allowhook) {  /* make sure there is a hook */
     int mask = CIST_HOOKED;
     CallInfo *ci = L->ci;
-    ptrdiff_t top = savestack(L, L->top);
-    ptrdiff_t ci_top = savestack(L, ci->top);
+    ptrdiff_t top = savestack(L, L->top);  /* preserve original 'top' */
+    ptrdiff_t ci_top = savestack(L, ci->top);  /* idem for 'ci->top' */
     lua_Debug ar;
     ar.event = event;
     ar.currentline = line;
@@ -308,8 +320,10 @@ void luaD_hook (lua_State *L, int event, int line,
       ci->u2.transferinfo.ftransfer = ftransfer;
       ci->u2.transferinfo.ntransfer = ntransfer;
     }
+    if (isLua(ci) && L->top < ci->top)
+      L->top = ci->top;  /* protect entire activation register */
     luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-    if (L->top + LUA_MINSTACK > ci->top)
+    if (ci->top < L->top + LUA_MINSTACK)
       ci->top = L->top + LUA_MINSTACK;
     L->allowhook = 0;  /* cannot call hooks inside a hook */
     ci->callstatus |= mask;
@@ -331,38 +345,40 @@ void luaD_hook (lua_State *L, int event, int line,
 ** active.
 */
 void luaD_hookcall (lua_State *L, CallInfo *ci) {
-  int hook = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL : LUA_HOOKCALL;
-  Proto *p;
-  if (!(L->hookmask & LUA_MASKCALL))  /* some other hook? */
-    return;  /* don't call hook */
-  p = clLvalue(s2v(ci->func))->p;
-  L->top = ci->top;  /* prepare top */
-  ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
-  luaD_hook(L, hook, -1, 1, p->numparams);
-  ci->u.l.savedpc--;  /* correct 'pc' */
-}
-
-
-static StkId rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
-  ptrdiff_t oldtop = savestack(L, L->top);  /* hook may change top */
-  int delta = 0;
-  if (isLuacode(ci)) {
+  L->oldpc = 0;  /* set 'oldpc' for new function */
+  if (L->hookmask & LUA_MASKCALL) {  /* is call hook on? */
+    int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL
+                                             : LUA_HOOKCALL;
     Proto *p = ci_func(ci)->p;
-    if (p->is_vararg)
-      delta = ci->u.l.nextraargs + p->numparams + 1;
-    if (L->top < ci->top)
-      L->top = ci->top;  /* correct top to run hook */
+    ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
+    luaD_hook(L, event, -1, 1, p->numparams);
+    ci->u.l.savedpc--;  /* correct 'pc' */
   }
+}
+
+
+/*
+** Executes a return hook for Lua and C functions and sets/corrects
+** 'oldpc'. (Note that this correction is needed by the line hook, so it
+** is done even when return hooks are off.)
+*/
+static void rethook (lua_State *L, CallInfo *ci, int nres) {
   if (L->hookmask & LUA_MASKRET) {  /* is return hook on? */
+    StkId firstres = L->top - nres;  /* index of first result */
+    int delta = 0;  /* correction for vararg functions */
     int ftransfer;
+    if (isLua(ci)) {
+      Proto *p = ci_func(ci)->p;
+      if (p->is_vararg)
+        delta = ci->u.l.nextraargs + p->numparams + 1;
+    }
     ci->func += delta;  /* if vararg, back to virtual 'func' */
     ftransfer = cast(unsigned short, firstres - ci->func);
     luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres);  /* call it */
     ci->func -= delta;
   }
   if (isLua(ci = ci->previous))
-    L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p);  /* update 'oldpc' */
-  return restorestack(L, oldtop);
+    L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p);  /* set 'oldpc' */
 }
 
 
@@ -371,15 +387,18 @@ static StkId rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
 ** stack, below original 'func', so that 'luaD_precall' can call it. Raise
 ** an error if there is no '__call' metafield.
 */
-void luaD_tryfuncTM (lua_State *L, StkId func) {
-  const TValue *tm = luaT_gettmbyobj(L, s2v(func), TM_CALL);
+StkId luaD_tryfuncTM (lua_State *L, StkId func) {
+  const TValue *tm;
   StkId p;
-  if (unlikely(ttisnil(tm)))
-    luaG_typeerror(L, s2v(func), "call");  /* nothing to call */
+  checkstackGCp(L, 1, func);  /* space for metamethod */
+  tm = luaT_gettmbyobj(L, s2v(func), TM_CALL);  /* (after previous GC) */
+  if (l_unlikely(ttisnil(tm)))
+    luaG_callerror(L, s2v(func));  /* nothing to call */
   for (p = L->top; p > func; p--)  /* open space for metamethod */
     setobjs2s(L, p, p-1);
   L->top++;  /* stack space pre-allocated by the caller */
   setobj2s(L, func, tm);  /* metamethod is the new function to be called */
+  return func;
 }
 
 
@@ -389,7 +408,7 @@ void luaD_tryfuncTM (lua_State *L, StkId func) {
 ** expressions, multiple results for tail calls/single parameters)
 ** separated.
 */
-static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
+l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
   StkId firstresult;
   int i;
   switch (wanted) {  /* handle typical cases separately */
@@ -399,27 +418,34 @@ static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
     case 1:  /* one value needed */
       if (nres == 0)   /* no results? */
         setnilvalue(s2v(res));  /* adjust with nil */
-      else
+      else  /* at least one result */
         setobjs2s(L, res, L->top - nres);  /* move it to proper place */
       L->top = res + 1;
       return;
     case LUA_MULTRET:
       wanted = nres;  /* we want all results */
       break;
-    default:  /* multiple results (or to-be-closed variables) */
+    default:  /* two/more results and/or to-be-closed variables */
       if (hastocloseCfunc(wanted)) {  /* to-be-closed variables? */
         ptrdiff_t savedres = savestack(L, res);
-        luaF_close(L, res, LUA_OK);  /* may change the stack */
-        res = restorestack(L, savedres);
-        wanted = codeNresults(wanted);  /* correct value */
+        L->ci->callstatus |= CIST_CLSRET;  /* in case of yields */
+        L->ci->u2.nres = nres;
+        luaF_close(L, res, CLOSEKTOP, 1);
+        L->ci->callstatus &= ~CIST_CLSRET;
+        if (L->hookmask)  /* if needed, call hook after '__close's */
+          rethook(L, L->ci, nres);
+        res = restorestack(L, savedres);  /* close and hook can move stack */
+        wanted = decodeNresults(wanted);
         if (wanted == LUA_MULTRET)
-          wanted = nres;
+          wanted = nres;  /* we want all results */
       }
       break;
   }
+  /* generic case */
   firstresult = L->top - nres;  /* index of first result */
-  /* move all results to correct place */
-  for (i = 0; i < nres && i < wanted; i++)
+  if (nres > wanted)  /* extra results? */
+    nres = wanted;  /* don't need them */
+  for (i = 0; i < nres; i++)  /* move all results to correct place */
     setobjs2s(L, res + i, firstresult + i);
   for (; i < wanted; i++)  /* complete wanted number of results */
     setnilvalue(s2v(res + i));
@@ -428,15 +454,21 @@ static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
 
 
 /*
-** Finishes a function call: calls hook if necessary, removes CallInfo,
-** moves current number of results to proper place.
+** Finishes a function call: calls hook if necessary, moves current
+** number of results to proper place, and returns to previous call
+** info. If function has to close variables, hook must be called after
+** that.
 */
 void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
-  if (L->hookmask)
-    L->top = rethook(L, ci, L->top - nres, nres);
-  L->ci = ci->previous;  /* back to caller */
+  int wanted = ci->nresults;
+  if (l_unlikely(L->hookmask && !hastocloseCfunc(wanted)))
+    rethook(L, ci, nres);
   /* move results to proper place */
-  moveresults(L, ci->func, nres, ci->nresults);
+  moveresults(L, ci->func, nres, wanted);
+  /* function cannot be in any of these cases when returning */
+  lua_assert(!(ci->callstatus &
+        (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET)));
+  L->ci = ci->previous;  /* back to caller (after closing variables) */
 }
 
 
@@ -444,27 +476,81 @@ void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
 #define next_ci(L)  (L->ci->next ? L->ci->next : luaE_extendCI(L))
 
 
+l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nret,
+                                                int mask, StkId top) {
+  CallInfo *ci = L->ci = next_ci(L);  /* new frame */
+  ci->func = func;
+  ci->nresults = nret;
+  ci->callstatus = mask;
+  ci->top = top;
+  return ci;
+}
+
+
+/*
+** precall for C functions
+*/
+l_sinline int precallC (lua_State *L, StkId func, int nresults,
+                                            lua_CFunction f) {
+  int n;  /* number of returns */
+  CallInfo *ci;
+  checkstackGCp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
+  L->ci = ci = prepCallInfo(L, func, nresults, CIST_C,
+                               L->top + LUA_MINSTACK);
+  lua_assert(ci->top <= L->stack_last);
+  if (l_unlikely(L->hookmask & LUA_MASKCALL)) {
+    int narg = cast_int(L->top - func) - 1;
+    luaD_hook(L, LUA_HOOKCALL, -1, 1, narg);
+  }
+  lua_unlock(L);
+  n = (*f)(L);  /* do the actual call */
+  lua_lock(L);
+  api_checknelems(L, n);
+  luaD_poscall(L, ci, n);
+  return n;
+}
+
+
 /*
 ** Prepare a function for a tail call, building its call info on top
 ** of the current call info. 'narg1' is the number of arguments plus 1
-** (so that it includes the function itself).
+** (so that it includes the function itself). Return the number of
+** results, if it was a C function, or -1 for a Lua function.
 */
-void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int narg1) {
-  Proto *p = clLvalue(s2v(func))->p;
-  int fsize = p->maxstacksize;  /* frame size */
-  int nfixparams = p->numparams;
-  int i;
-  for (i = 0; i < narg1; i++)  /* move down function and arguments */
-    setobjs2s(L, ci->func + i, func + i);
-  checkstackGC(L, fsize);
-  func = ci->func;  /* moved-down function */
-  for (; narg1 <= nfixparams; narg1++)
-    setnilvalue(s2v(func + narg1));  /* complete missing arguments */
-  ci->top = func + 1 + fsize;  /* top for new function */
-  lua_assert(ci->top <= L->stack_last);
-  ci->u.l.savedpc = p->code;  /* starting point */
-  ci->callstatus |= CIST_TAIL;
-  L->top = func + narg1;  /* set top */
+int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func,
+                                    int narg1, int delta) {
+ retry:
+  switch (ttypetag(s2v(func))) {
+    case LUA_VCCL:  /* C closure */
+      return precallC(L, func, LUA_MULTRET, clCvalue(s2v(func))->f);
+    case LUA_VLCF:  /* light C function */
+      return precallC(L, func, LUA_MULTRET, fvalue(s2v(func)));
+    case LUA_VLCL: {  /* Lua function */
+      Proto *p = clLvalue(s2v(func))->p;
+      int fsize = p->maxstacksize;  /* frame size */
+      int nfixparams = p->numparams;
+      int i;
+      checkstackGCp(L, fsize - delta, func);
+      ci->func -= delta;  /* restore 'func' (if vararg) */
+      for (i = 0; i < narg1; i++)  /* move down function and arguments */
+        setobjs2s(L, ci->func + i, func + i);
+      func = ci->func;  /* moved-down function */
+      for (; narg1 <= nfixparams; narg1++)
+        setnilvalue(s2v(func + narg1));  /* complete missing arguments */
+      ci->top = func + 1 + fsize;  /* top for new function */
+      lua_assert(ci->top <= L->stack_last);
+      ci->u.l.savedpc = p->code;  /* starting point */
+      ci->callstatus |= CIST_TAIL;
+      L->top = func + narg1;  /* set top */
+      return -1;
+    }
+    default: {  /* not a function */
+      func = luaD_tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      /* return luaD_pretailcall(L, ci, func, narg1 + 1, delta); */
+      narg1++;
+      goto retry;  /* try again */
+    }
+  }
 }
 
 
@@ -477,35 +563,14 @@ void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int narg1) {
 ** original function position.
 */
 CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
-  lua_CFunction f;
  retry:
   switch (ttypetag(s2v(func))) {
     case LUA_VCCL:  /* C closure */
-      f = clCvalue(s2v(func))->f;
-      goto Cfunc;
+      precallC(L, func, nresults, clCvalue(s2v(func))->f);
+      return NULL;
     case LUA_VLCF:  /* light C function */
-      f = fvalue(s2v(func));
-     Cfunc: {
-      int n;  /* number of returns */
-      CallInfo *ci;
-      checkstackGCp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
-      L->ci = ci = next_ci(L);
-      ci->nresults = nresults;
-      ci->callstatus = CIST_C;
-      ci->top = L->top + LUA_MINSTACK;
-      ci->func = func;
-      lua_assert(ci->top <= L->stack_last);
-      if (L->hookmask & LUA_MASKCALL) {
-        int narg = cast_int(L->top - func) - 1;
-        luaD_hook(L, LUA_HOOKCALL, -1, 1, narg);
-      }
-      lua_unlock(L);
-      n = (*f)(L);  /* do the actual call */
-      lua_lock(L);
-      api_checknelems(L, n);
-      luaD_poscall(L, ci, n);
+      precallC(L, func, nresults, fvalue(s2v(func)));
       return NULL;
-    }
     case LUA_VLCL: {  /* Lua function */
       CallInfo *ci;
       Proto *p = clLvalue(s2v(func))->p;
@@ -513,20 +578,16 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
       int nfixparams = p->numparams;
       int fsize = p->maxstacksize;  /* frame size */
       checkstackGCp(L, fsize, func);
-      L->ci = ci = next_ci(L);
-      ci->nresults = nresults;
+      L->ci = ci = prepCallInfo(L, func, nresults, 0, func + 1 + fsize);
       ci->u.l.savedpc = p->code;  /* starting point */
-      ci->top = func + 1 + fsize;
-      ci->func = func;
-      L->ci = ci;
       for (; narg < nfixparams; narg++)
         setnilvalue(s2v(L->top++));  /* complete missing arguments */
       lua_assert(ci->top <= L->stack_last);
       return ci;
     }
     default: {  /* not a function */
-      checkstackGCp(L, 1, func);  /* space for metamethod */
-      luaD_tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      func = luaD_tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      /* return luaD_precall(L, func, nresults); */
       goto retry;  /* try again with metamethod */
     }
   }
@@ -538,10 +599,10 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
 ** number of recursive invocations in the C stack) or nyci (the same
 ** plus increment number of non-yieldable calls).
 */
-static void ccall (lua_State *L, StkId func, int nResults, int inc) {
+l_sinline void ccall (lua_State *L, StkId func, int nResults, int inc) {
   CallInfo *ci;
   L->nCcalls += inc;
-  if (unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
+  if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
     luaE_checkcstack(L);
   if ((ci = luaD_precall(L, func, nResults)) != NULL) {  /* Lua function? */
     ci->callstatus = CIST_FRESH;  /* mark that it is a "fresh" execute */
@@ -568,27 +629,74 @@ void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
 
 
 /*
-** Completes the execution of an interrupted C function, calling its
-** continuation function.
+** Finish the job of 'lua_pcallk' after it was interrupted by an yield.
+** (The caller, 'finishCcall', does the final call to 'adjustresults'.)
+** The main job is to complete the 'luaD_pcall' called by 'lua_pcallk'.
+** If a '__close' method yields here, eventually control will be back
+** to 'finishCcall' (when that '__close' method finally returns) and
+** 'finishpcallk' will run again and close any still pending '__close'
+** methods. Similarly, if a '__close' method errs, 'precover' calls
+** 'unroll' which calls ''finishCcall' and we are back here again, to
+** close any pending '__close' methods.
+** Note that, up to the call to 'luaF_close', the corresponding
+** 'CallInfo' is not modified, so that this repeated run works like the
+** first one (except that it has at least one less '__close' to do). In
+** particular, field CIST_RECST preserves the error status across these
+** multiple runs, changing only if there is a new error.
 */
-static void finishCcall (lua_State *L, int status) {
-  CallInfo *ci = L->ci;
-  int n;
-  /* must have a continuation and must be able to call it */
-  lua_assert(ci->u.c.k != NULL && yieldable(L));
-  /* error status can only happen in a protected call */
-  lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
-  if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
-    ci->callstatus &= ~CIST_YPCALL;  /* continuation is also inside it */
-    L->errfunc = ci->u.c.old_errfunc;  /* with the same error function */
-  }
-  /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
-     handled */
-  adjustresults(L, ci->nresults);
-  lua_unlock(L);
-  n = (*ci->u.c.k)(L, status, ci->u.c.ctx);  /* call continuation function */
-  lua_lock(L);
-  api_checknelems(L, n);
+static int finishpcallk (lua_State *L,  CallInfo *ci) {
+  int status = getcistrecst(ci);  /* get original status */
+  if (l_likely(status == LUA_OK))  /* no error? */
+    status = LUA_YIELD;  /* was interrupted by an yield */
+  else {  /* error */
+    StkId func = restorestack(L, ci->u2.funcidx);
+    L->allowhook = getoah(ci->callstatus);  /* restore 'allowhook' */
+    luaF_close(L, func, status, 1);  /* can yield or raise an error */
+    func = restorestack(L, ci->u2.funcidx);  /* stack may be moved */
+    luaD_seterrorobj(L, status, func);
+    luaD_shrinkstack(L);   /* restore stack size in case of overflow */
+    setcistrecst(ci, LUA_OK);  /* clear original status */
+  }
+  ci->callstatus &= ~CIST_YPCALL;
+  L->errfunc = ci->u.c.old_errfunc;
+  /* if it is here, there were errors or yields; unlike 'lua_pcallk',
+     do not change status */
+  return status;
+}
+
+
+/*
+** Completes the execution of a C function interrupted by an yield.
+** The interruption must have happened while the function was either
+** closing its tbc variables in 'moveresults' or executing
+** 'lua_callk'/'lua_pcallk'. In the first case, it just redoes
+** 'luaD_poscall'. In the second case, the call to 'finishpcallk'
+** finishes the interrupted execution of 'lua_pcallk'.  After that, it
+** calls the continuation of the interrupted function and finally it
+** completes the job of the 'luaD_call' that called the function.  In
+** the call to 'adjustresults', we do not know the number of results
+** of the function called by 'lua_callk'/'lua_pcallk', so we are
+** conservative and use LUA_MULTRET (always adjust).
+*/
+static void finishCcall (lua_State *L, CallInfo *ci) {
+  int n;  /* actual number of results from C function */
+  if (ci->callstatus & CIST_CLSRET) {  /* was returning? */
+    lua_assert(hastocloseCfunc(ci->nresults));
+    n = ci->u2.nres;  /* just redo 'luaD_poscall' */
+    /* don't need to reset CIST_CLSRET, as it will be set again anyway */
+  }
+  else {
+    int status = LUA_YIELD;  /* default if there were no errors */
+    /* must have a continuation and must be able to call it */
+    lua_assert(ci->u.c.k != NULL && yieldable(L));
+    if (ci->callstatus & CIST_YPCALL)   /* was inside a 'lua_pcallk'? */
+      status = finishpcallk(L, ci);  /* finish it */
+    adjustresults(L, LUA_MULTRET);  /* finish 'lua_callk' */
+    lua_unlock(L);
+    n = (*ci->u.c.k)(L, status, ci->u.c.ctx);  /* call continuation */
+    lua_lock(L);
+    api_checknelems(L, n);
+  }
   luaD_poscall(L, ci, n);  /* finish 'luaD_call' */
 }
 
@@ -596,18 +704,14 @@ static void finishCcall (lua_State *L, int status) {
 /*
 ** Executes "full continuation" (everything in the stack) of a
 ** previously interrupted coroutine until the stack is empty (or another
-** interruption long-jumps out of the loop). If the coroutine is
-** recovering from an error, 'ud' points to the error status, which must
-** be passed to the first continuation function (otherwise the default
-** status is LUA_YIELD).
+** interruption long-jumps out of the loop).
 */
 static void unroll (lua_State *L, void *ud) {
   CallInfo *ci;
-  if (ud != NULL)  /* error status? */
-    finishCcall(L, *(int *)ud);  /* finish 'lua_pcallk' callee */
+  UNUSED(ud);
   while ((ci = L->ci) != &L->base_ci) {  /* something in the stack */
     if (!isLua(ci))  /* C function? */
-      finishCcall(L, LUA_YIELD);  /* complete its execution */
+      finishCcall(L, ci);  /* complete its execution */
     else {  /* Lua function */
       luaV_finishOp(L);  /* finish interrupted instruction */
       luaV_execute(L, ci);  /* execute down to higher C 'boundary' */
@@ -631,28 +735,6 @@ static CallInfo *findpcall (lua_State *L) {
 
 
 /*
-** Recovers from an error in a coroutine. Finds a recover point (if
-** there is one) and completes the execution of the interrupted
-** 'luaD_pcall'. If there is no recover point, returns zero.
-*/
-static int recover (lua_State *L, int status) {
-  StkId oldtop;
-  CallInfo *ci = findpcall(L);
-  if (ci == NULL) return 0;  /* no recovery point */
-  /* "finish" luaD_pcall */
-  oldtop = restorestack(L, ci->u2.funcidx);
-  L->ci = ci;
-  L->allowhook = getoah(ci->callstatus);  /* restore original 'allowhook' */
-  status = luaF_close(L, oldtop, status);  /* may change the stack */
-  oldtop = restorestack(L, ci->u2.funcidx);
-  luaD_seterrorobj(L, status, oldtop);
-  luaD_shrinkstack(L);   /* restore stack size in case of overflow */
-  L->errfunc = ci->u.c.old_errfunc;
-  return 1;  /* continue running the coroutine */
-}
-
-
-/*
 ** Signal an error in the call to 'lua_resume', not in the execution
 ** of the coroutine itself. (Such errors should not be handled by any
 ** coroutine error handler and should not kill the coroutine.)
@@ -678,13 +760,14 @@ static void resume (lua_State *L, void *ud) {
   StkId firstArg = L->top - n;  /* first argument */
   CallInfo *ci = L->ci;
   if (L->status == LUA_OK)  /* starting a coroutine? */
-    ccall(L, firstArg - 1, LUA_MULTRET, 1);  /* just call its body */
+    ccall(L, firstArg - 1, LUA_MULTRET, 0);  /* just call its body */
   else {  /* resuming from previous yield */
     lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
-    luaE_incCstack(L);  /* control the C stack */
-    if (isLua(ci))  /* yielded inside a hook? */
+    if (isLua(ci)) {  /* yielded inside a hook? */
+      L->top = firstArg;  /* discard arguments */
       luaV_execute(L, ci);  /* just continue running Lua code */
+    }
     else {  /* 'common' yield */
       if (ci->u.c.k != NULL) {  /* does it have a continuation function? */
         lua_unlock(L);
@@ -698,6 +781,26 @@ static void resume (lua_State *L, void *ud) {
   }
 }
 
+
+/*
+** Unrolls a coroutine in protected mode while there are recoverable
+** errors, that is, errors inside a protected call. (Any error
+** interrupts 'unroll', and this loop protects it again so it can
+** continue.) Stops with a normal end (status == LUA_OK), an yield
+** (status == LUA_YIELD), or an unprotected error ('findpcall' doesn't
+** find a recover point).
+*/
+static int precover (lua_State *L, int status) {
+  CallInfo *ci;
+  while (errorstatus(status) && (ci = findpcall(L)) != NULL) {
+    L->ci = ci;  /* go down to recovery functions */
+    setcistrecst(ci, status);  /* status to finish 'pcall' */
+    status = luaD_rawrunprotected(L, unroll, NULL);
+  }
+  return status;
+}
+
+
 LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
                                       int *nresults) {
   int status;
@@ -711,15 +814,15 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
   else if (L->status != LUA_YIELD)  /* ended with errors? */
     return resume_error(L, "cannot resume dead coroutine", nargs);
   L->nCcalls = (from) ? getCcalls(from) : 0;
+  if (getCcalls(L) >= LUAI_MAXCCALLS)
+    return resume_error(L, "C stack overflow", nargs);
+  L->nCcalls++;
   luai_userstateresume(L, nargs);
   api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
   status = luaD_rawrunprotected(L, resume, &nargs);
    /* continue running after recoverable errors */
-  while (errorstatus(status) && recover(L, status)) {
-    /* unroll continuation */
-    status = luaD_rawrunprotected(L, unroll, &status);
-  }
-  if (likely(!errorstatus(status)))
+  status = precover(L, status);
+  if (l_likely(!errorstatus(status)))
     lua_assert(status == L->status);  /* normal end or yield */
   else {  /* unrecoverable error */
     L->status = cast_byte(status);  /* mark thread as 'dead' */
@@ -745,22 +848,22 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
   lua_lock(L);
   ci = L->ci;
   api_checknelems(L, nresults);
-  if (unlikely(!yieldable(L))) {
+  if (l_unlikely(!yieldable(L))) {
     if (L != G(L)->mainthread)
       luaG_runerror(L, "attempt to yield across a C-call boundary");
     else
       luaG_runerror(L, "attempt to yield from outside a coroutine");
   }
   L->status = LUA_YIELD;
+  ci->u2.nyield = nresults;  /* save number of results */
   if (isLua(ci)) {  /* inside a hook? */
     lua_assert(!isLuacode(ci));
+    api_check(L, nresults == 0, "hooks cannot yield values");
     api_check(L, k == NULL, "hooks cannot continue after yielding");
-    ci->u2.nyield = 0;  /* no results */
   }
   else {
     if ((ci->u.c.k = k) != NULL)  /* is there a continuation? */
       ci->u.c.ctx = ctx;  /* save context */
-    ci->u2.nyield = nresults;  /* save number of results */
     luaD_throw(L, LUA_YIELD);
   }
   lua_assert(ci->callstatus & CIST_HOOKED);  /* must be inside a hook */
@@ -770,6 +873,45 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
 
 
 /*
+** Auxiliary structure to call 'luaF_close' in protected mode.
+*/
+struct CloseP {
+  StkId level;
+  int status;
+};
+
+
+/*
+** Auxiliary function to call 'luaF_close' in protected mode.
+*/
+static void closepaux (lua_State *L, void *ud) {
+  struct CloseP *pcl = cast(struct CloseP *, ud);
+  luaF_close(L, pcl->level, pcl->status, 0);
+}
+
+
+/*
+** Calls 'luaF_close' in protected mode. Return the original status
+** or, in case of errors, the new status.
+*/
+int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status) {
+  CallInfo *old_ci = L->ci;
+  lu_byte old_allowhooks = L->allowhook;
+  for (;;) {  /* keep closing upvalues until no more errors */
+    struct CloseP pcl;
+    pcl.level = restorestack(L, level); pcl.status = status;
+    status = luaD_rawrunprotected(L, &closepaux, &pcl);
+    if (l_likely(status == LUA_OK))  /* no more errors? */
+      return pcl.status;
+    else {  /* an error occurred; restore saved state and repeat */
+      L->ci = old_ci;
+      L->allowhook = old_allowhooks;
+    }
+  }
+}
+
+
+/*
 ** Call the C function 'func' in protected mode, restoring basic
 ** thread information ('allowhook', etc.) and in particular
 ** its stack level in case of errors.
@@ -782,13 +924,11 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
   ptrdiff_t old_errfunc = L->errfunc;
   L->errfunc = ef;
   status = luaD_rawrunprotected(L, func, u);
-  if (unlikely(status != LUA_OK)) {  /* an error occurred? */
-    StkId oldtop = restorestack(L, old_top);
+  if (l_unlikely(status != LUA_OK)) {  /* an error occurred? */
     L->ci = old_ci;
     L->allowhook = old_allowhooks;
-    status = luaF_close(L, oldtop, status);
-    oldtop = restorestack(L, old_top);  /* previous call may change stack */
-    luaD_seterrorobj(L, status, oldtop);
+    status = luaD_closeprotected(L, old_top, status);
+    luaD_seterrorobj(L, status, restorestack(L, old_top));
     luaD_shrinkstack(L);   /* restore stack size in case of overflow */
   }
   L->errfunc = old_errfunc;
diff --git a/contrib/lua/src/ldo.h b/contrib/lua/src/ldo.h
index 4d30d072ede3..911e67f660a1 100644
--- a/contrib/lua/src/ldo.h
+++ b/contrib/lua/src/ldo.h
@@ -23,7 +23,7 @@
 ** at every check.
 */
 #define luaD_checkstackaux(L,n,pre,pos)  \
-	if (L->stack_last - L->top <= (n)) \
+	if (l_unlikely(L->stack_last - L->top <= (n))) \
 	  { pre; luaD_growstack(L, n, 1); pos; } \
         else { condmovestack(L,pre,pos); }
 
@@ -58,11 +58,12 @@ LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
 LUAI_FUNC void luaD_hook (lua_State *L, int event, int line,
                                         int fTransfer, int nTransfer);
 LUAI_FUNC void luaD_hookcall (lua_State *L, CallInfo *ci);
-LUAI_FUNC void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int n);
+LUAI_FUNC int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func,                                                    int narg1, int delta);
 LUAI_FUNC CallInfo *luaD_precall (lua_State *L, StkId func, int nResults);
 LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
 LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
-LUAI_FUNC void luaD_tryfuncTM (lua_State *L, StkId func);
+LUAI_FUNC StkId luaD_tryfuncTM (lua_State *L, StkId func);
+LUAI_FUNC int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status);
 LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
                                         ptrdiff_t oldtop, ptrdiff_t ef);
 LUAI_FUNC void luaD_poscall (lua_State *L, CallInfo *ci, int nres);
diff --git a/contrib/lua/src/lfunc.c b/contrib/lua/src/lfunc.c
index c4360f0950a7..f5889a21d12e 100644
--- a/contrib/lua/src/lfunc.c
+++ b/contrib/lua/src/lfunc.c
@@ -100,115 +100,83 @@ UpVal *luaF_findupval (lua_State *L, StkId level) {
 }
 
 
-static void callclose (lua_State *L, void *ud) {
-  UNUSED(ud);
-  luaD_callnoyield(L, L->top - 3, 0);
-}
-
-
 /*
-** Prepare closing method plus its arguments for object 'obj' with
-** error message 'err'. (This function assumes EXTRA_STACK.)
+** Call closing method for object 'obj' with error message 'err'. The
+** boolean 'yy' controls whether the call is yieldable.
+** (This function assumes EXTRA_STACK.)
 */
-static int prepclosingmethod (lua_State *L, TValue *obj, TValue *err) {
+static void callclosemethod (lua_State *L, TValue *obj, TValue *err, int yy) {
   StkId top = L->top;
   const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
-  if (ttisnil(tm))  /* no metamethod? */
-    return 0;  /* nothing to call */
   setobj2s(L, top, tm);  /* will call metamethod... */
   setobj2s(L, top + 1, obj);  /* with 'self' as the 1st argument */
   setobj2s(L, top + 2, err);  /* and error msg. as 2nd argument */
   L->top = top + 3;  /* add function and arguments */
-  return 1;
+  if (yy)
+    luaD_call(L, top, 0);
+  else
+    luaD_callnoyield(L, top, 0);
 }
 
 
 /*
-** Raise an error with message 'msg', inserting the name of the
-** local variable at position 'level' in the stack.
+** Check whether object at given level has a close metamethod and raise
+** an error if not.
 */
-static void varerror (lua_State *L, StkId level, const char *msg) {
-  int idx = cast_int(level - L->ci->func);
-  const char *vname = luaG_findlocal(L, L->ci, idx, NULL);
-  if (vname == NULL) vname = "?";
-  luaG_runerror(L, msg, vname);
+static void checkclosemth (lua_State *L, StkId level) {
+  const TValue *tm = luaT_gettmbyobj(L, s2v(level), TM_CLOSE);
+  if (ttisnil(tm)) {  /* no metamethod? */
+    int idx = cast_int(level - L->ci->func);  /* variable index */
+    const char *vname = luaG_findlocal(L, L->ci, idx, NULL);
+    if (vname == NULL) vname = "?";
+    luaG_runerror(L, "variable '%s' got a non-closable value", vname);
+  }
 }
 
 
 /*
-** Prepare and call a closing method. If status is OK, code is still
-** inside the original protected call, and so any error will be handled
-** there. Otherwise, a previous error already activated the original
-** protected call, and so the call to the closing method must be
-** protected here. (A status == CLOSEPROTECT behaves like a previous
-** error, to also run the closing method in protected mode).
-** If status is OK, the call to the closing method will be pushed
-** at the top of the stack. Otherwise, values are pushed after
-** the 'level' of the upvalue being closed, as everything after
-** that won't be used again.
+** Prepare and call a closing method.
+** If status is CLOSEKTOP, the call to the closing method will be pushed
+** at the top of the stack. Otherwise, values can be pushed right after
+** the 'level' of the upvalue being closed, as everything after that
+** won't be used again.
 */
-static int callclosemth (lua_State *L, StkId level, int status) {
+static void prepcallclosemth (lua_State *L, StkId level, int status, int yy) {
   TValue *uv = s2v(level);  /* value being closed */
-  if (likely(status == LUA_OK)) {
-    if (prepclosingmethod(L, uv, &G(L)->nilvalue))  /* something to call? */
-      callclose(L, NULL);  /* call closing method */
-    else if (!l_isfalse(uv))  /* non-closable non-false value? */
-      varerror(L, level, "attempt to close non-closable variable '%s'");
-  }
-  else {  /* must close the object in protected mode */
-    ptrdiff_t oldtop;
-    level++;  /* space for error message */
-    oldtop = savestack(L, level + 1);  /* top will be after that */
-    luaD_seterrorobj(L, status, level);  /* set error message */
-    if (prepclosingmethod(L, uv, s2v(level))) {  /* something to call? */
-      int newstatus = luaD_pcall(L, callclose, NULL, oldtop, 0);
-      if (newstatus != LUA_OK && status == CLOSEPROTECT)  /* first error? */
-        status = newstatus;  /* this will be the new error */
-      else {
-        if (newstatus != LUA_OK)  /* suppressed error? */
-          luaE_warnerror(L, "__close metamethod");
-        /* leave original error (or nil) on top */
-        L->top = restorestack(L, oldtop);
-      }
-    }
-    /* else no metamethod; ignore this case and keep original error */
+  TValue *errobj;
+  if (status == CLOSEKTOP)
+    errobj = &G(L)->nilvalue;  /* error object is nil */
+  else {  /* 'luaD_seterrorobj' will set top to level + 2 */
+    errobj = s2v(level + 1);  /* error object goes after 'uv' */
+    luaD_seterrorobj(L, status, level + 1);  /* set error object */
   }
-  return status;
+  callclosemethod(L, uv, errobj, yy);
 }
 
 
 /*
-** Try to create a to-be-closed upvalue
-** (can raise a memory-allocation error)
+** Maximum value for deltas in 'tbclist', dependent on the type
+** of delta. (This macro assumes that an 'L' is in scope where it
+** is used.)
 */
-static void trynewtbcupval (lua_State *L, void *ud) {
-  newupval(L, 1, cast(StkId, ud), &L->openupval);
-}
+#define MAXDELTA  \
+	((256ul << ((sizeof(L->stack->tbclist.delta) - 1) * 8)) - 1)
 
 
 /*
-** Create a to-be-closed upvalue. If there is a memory error
-** when creating the upvalue, the closing method must be called here,
-** as there is no upvalue to call it later.
+** Insert a variable in the list of to-be-closed variables.
 */
 void luaF_newtbcupval (lua_State *L, StkId level) {
-  TValue *obj = s2v(level);
-  lua_assert(L->openupval == NULL || uplevel(L->openupval) < level);
-  if (!l_isfalse(obj)) {  /* false doesn't need to be closed */
-    int status;
-    const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
-    if (ttisnil(tm))  /* no metamethod? */
-      varerror(L, level, "variable '%s' got a non-closable value");
-    status = luaD_rawrunprotected(L, trynewtbcupval, level);
-    if (unlikely(status != LUA_OK)) {  /* memory error creating upvalue? */
-      lua_assert(status == LUA_ERRMEM);
-      luaD_seterrorobj(L, LUA_ERRMEM, level + 1);  /* save error message */
-      /* next call must succeed, as object is closable */
-      prepclosingmethod(L, s2v(level), s2v(level + 1));
-      callclose(L, NULL);  /* call closing method */
-      luaD_throw(L, LUA_ERRMEM);  /* throw memory error */
-    }
+  lua_assert(level > L->tbclist);
+  if (l_isfalse(s2v(level)))
+    return;  /* false doesn't need to be closed */
+  checkclosemth(L, level);  /* value must have a close method */
+  while (cast_uint(level - L->tbclist) > MAXDELTA) {
+    L->tbclist += MAXDELTA;  /* create a dummy node at maximum delta */
+    L->tbclist->tbclist.delta = 0;
   }
+  level->tbclist.delta = cast(unsigned short, level - L->tbclist);
+  L->tbclist = level;
 }
 
 
@@ -220,18 +188,16 @@ void luaF_unlinkupval (UpVal *uv) {
 }
 
 
-int luaF_close (lua_State *L, StkId level, int status) {
+/*
+** Close all upvalues up to the given stack level.
+*/
+void luaF_closeupval (lua_State *L, StkId level) {
   UpVal *uv;
-  while ((uv = L->openupval) != NULL && uplevel(uv) >= level) {
+  StkId upl;  /* stack index pointed by 'uv' */
+  while ((uv = L->openupval) != NULL && (upl = uplevel(uv)) >= level) {
     TValue *slot = &uv->u.value;  /* new position for value */
     lua_assert(uplevel(uv) < L->top);
-    if (uv->tbc && status != NOCLOSINGMETH) {
-      /* must run closing method, which may change the stack */
-      ptrdiff_t levelrel = savestack(L, level);
-      status = callclosemth(L, uplevel(uv), status);
-      level = restorestack(L, levelrel);
-    }
-    luaF_unlinkupval(uv);
+    luaF_unlinkupval(uv);  /* remove upvalue from 'openupval' list */
     setobj(L, slot, uv->v);  /* move value to upvalue slot */
     uv->v = slot;  /* now current value lives here */
     if (!iswhite(uv)) {  /* neither white nor dead? */
@@ -239,7 +205,35 @@ int luaF_close (lua_State *L, StkId level, int status) {
       luaC_barrier(L, uv, slot);
     }
   }
-  return status;
+}
+
+
+/*
+** Remove firt element from the tbclist plus its dummy nodes.
+*/
+static void poptbclist (lua_State *L) {
+  StkId tbc = L->tbclist;
+  lua_assert(tbc->tbclist.delta > 0);  /* first element cannot be dummy */
+  tbc -= tbc->tbclist.delta;
+  while (tbc > L->stack && tbc->tbclist.delta == 0)
+    tbc -= MAXDELTA;  /* remove dummy nodes */
+  L->tbclist = tbc;
+}
+
+
+/*
+** Close all upvalues and to-be-closed variables up to the given stack
+** level.
+*/
+void luaF_close (lua_State *L, StkId level, int status, int yy) {
+  ptrdiff_t levelrel = savestack(L, level);
+  luaF_closeupval(L, level);  /* first, close the upvalues */
+  while (L->tbclist >= level) {  /* traverse tbc's down to that level */
+    StkId tbc = L->tbclist;  /* get variable index */
+    poptbclist(L);  /* remove it from list */
+    prepcallclosemth(L, tbc, status, yy);  /* close variable */
+    level = restorestack(L, levelrel);
+  }
 }
 
 
diff --git a/contrib/lua/src/lfunc.h b/contrib/lua/src/lfunc.h
index 8d6f965cfca9..dc1cebccd1bc 100644
--- a/contrib/lua/src/lfunc.h
+++ b/contrib/lua/src/lfunc.h
@@ -42,15 +42,9 @@
 #define MAXMISS		10
 
 
-/*
-** Special "status" for 'luaF_close'
-*/
-
-/* close upvalues without running their closing methods */
-#define NOCLOSINGMETH	(-1)
 
-/* close upvalues running all closing methods in protected mode */
-#define CLOSEPROTECT	(-2)
+/* special status to close upvalues preserving the top of the stack */
+#define CLOSEKTOP	(-1)
 
 
 LUAI_FUNC Proto *luaF_newproto (lua_State *L);
@@ -59,7 +53,8 @@ LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nupvals);
 LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
 LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
 LUAI_FUNC void luaF_newtbcupval (lua_State *L, StkId level);
-LUAI_FUNC int luaF_close (lua_State *L, StkId level, int status);
+LUAI_FUNC void luaF_closeupval (lua_State *L, StkId level);
+LUAI_FUNC void luaF_close (lua_State *L, StkId level, int status, int yy);
 LUAI_FUNC void luaF_unlinkupval (UpVal *uv);
 LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
 LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
diff --git a/contrib/lua/src/lgc.c b/contrib/lua/src/lgc.c
index bab9beb12b00..42a73d813acc 100644
--- a/contrib/lua/src/lgc.c
+++ b/contrib/lua/src/lgc.c
@@ -906,18 +906,18 @@ static void GCTM (lua_State *L) {
   if (!notm(tm)) {  /* is there a finalizer? */
     int status;
     lu_byte oldah = L->allowhook;
-    int running  = g->gcrunning;
+    int oldgcstp  = g->gcstp;
+    g->gcstp |= GCSTPGC;  /* avoid GC steps */
     L->allowhook = 0;  /* stop debug hooks during GC metamethod */
-    g->gcrunning = 0;  /* avoid GC steps */
     setobj2s(L, L->top++, tm);  /* push finalizer... */
     setobj2s(L, L->top++, &v);  /* ... and its argument */
     L->ci->callstatus |= CIST_FIN;  /* will run a finalizer */
     status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
     L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
     L->allowhook = oldah;  /* restore hooks */
-    g->gcrunning = running;  /* restore state */
-    if (unlikely(status != LUA_OK)) {  /* error while running __gc? */
-      luaE_warnerror(L, "__gc metamethod");
+    g->gcstp = oldgcstp;  /* restore state */
+    if (l_unlikely(status != LUA_OK)) {  /* error while running __gc? */
+      luaE_warnerror(L, "__gc");
       L->top--;  /* pops error object */
     }
   }
@@ -1011,7 +1011,8 @@ static void correctpointers (global_State *g, GCObject *o) {
 void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
   global_State *g = G(L);
   if (tofinalize(o) ||                 /* obj. is already marked... */
-      gfasttm(g, mt, TM_GC) == NULL)   /* or has no finalizer? */
+      gfasttm(g, mt, TM_GC) == NULL ||    /* or has no finalizer... */
+      (g->gcstp & GCSTPCLS))                   /* or closing state? */
     return;  /* nothing to be done */
   else {  /* move 'o' to 'finobj' list */
     GCObject **p;
@@ -1502,12 +1503,13 @@ static void deletelist (lua_State *L, GCObject *p, GCObject *limit) {
 */
 void luaC_freeallobjects (lua_State *L) {
   global_State *g = G(L);
+  g->gcstp = GCSTPCLS;  /* no extra finalizers after here */
   luaC_changemode(L, KGC_INC);
   separatetobefnz(g, 1);  /* separate all objects with finalizers */
   lua_assert(g->finobj == NULL);
   callallpendingfinalizers(L);
   deletelist(L, g->allgc, obj2gco(g->mainthread));
-  deletelist(L, g->finobj, NULL);
+  lua_assert(g->finobj == NULL);  /* no new finalizers */
   deletelist(L, g->fixedgc, NULL);  /* collect fixed objects */
   lua_assert(g->strt.nuse == 0);
 }
@@ -1575,52 +1577,64 @@ static int sweepstep (lua_State *L, global_State *g,
 
 static lu_mem singlestep (lua_State *L) {
   global_State *g = G(L);
+  lu_mem work;
+  lua_assert(!g->gcstopem);  /* collector is not reentrant */
+  g->gcstopem = 1;  /* no emergency collections while collecting */
   switch (g->gcstate) {
     case GCSpause: {
       restartcollection(g);
       g->gcstate = GCSpropagate;
-      return 1;
+      work = 1;
+      break;
     }
     case GCSpropagate: {
       if (g->gray == NULL) {  /* no more gray objects? */
         g->gcstate = GCSenteratomic;  /* finish propagate phase */
-        return 0;
+        work = 0;
       }
       else
-        return propagatemark(g);  /* traverse one gray object */
+        work = propagatemark(g);  /* traverse one gray object */
+      break;
     }
     case GCSenteratomic: {
-      lu_mem work = atomic(L);  /* work is what was traversed by 'atomic' */
+      work = atomic(L);  /* work is what was traversed by 'atomic' */
       entersweep(L);
       g->GCestimate = gettotalbytes(g);  /* first estimate */;
-      return work;
+      break;
     }
     case GCSswpallgc: {  /* sweep "regular" objects */
-      return sweepstep(L, g, GCSswpfinobj, &g->finobj);
+      work = sweepstep(L, g, GCSswpfinobj, &g->finobj);
+      break;
     }
     case GCSswpfinobj: {  /* sweep objects with finalizers */
-      return sweepstep(L, g, GCSswptobefnz, &g->tobefnz);
+      work = sweepstep(L, g, GCSswptobefnz, &g->tobefnz);
+      break;
     }
     case GCSswptobefnz: {  /* sweep objects to be finalized */
-      return sweepstep(L, g, GCSswpend, NULL);
+      work = sweepstep(L, g, GCSswpend, NULL);
+      break;
     }
     case GCSswpend: {  /* finish sweeps */
       checkSizes(L, g);
       g->gcstate = GCScallfin;
-      return 0;
+      work = 0;
+      break;
     }
     case GCScallfin: {  /* call remaining finalizers */
       if (g->tobefnz && !g->gcemergency) {
-        int n = runafewfinalizers(L, GCFINMAX);
-        return n * GCFINALIZECOST;
+        g->gcstopem = 0;  /* ok collections during finalizers */
+        work = runafewfinalizers(L, GCFINMAX) * GCFINALIZECOST;
       }
       else {  /* emergency mode or no more finalizers */
         g->gcstate = GCSpause;  /* finish collection */
-        return 0;
+        work = 0;
       }
+      break;
     }
     default: lua_assert(0); return 0;
   }
+  g->gcstopem = 0;
+  return work;
 }
 
 
@@ -1635,6 +1649,7 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
 }
 
 
+
 /*
 ** Performs a basic incremental step. The debt and step size are
 ** converted from bytes to "units of work"; then the function loops
@@ -1666,7 +1681,7 @@ static void incstep (lua_State *L, global_State *g) {
 void luaC_step (lua_State *L) {
   global_State *g = G(L);
   lua_assert(!g->gcemergency);
-  if (g->gcrunning) {  /* running? */
+  if (gcrunning(g)) {  /* running? */
     if(isdecGCmodegen(g))
       genstep(L, g);
     else
diff --git a/contrib/lua/src/lgc.h b/contrib/lua/src/lgc.h
index 073e2a402948..4a125634b9ea 100644
--- a/contrib/lua/src/lgc.h
+++ b/contrib/lua/src/lgc.h
@@ -148,6 +148,16 @@
 */
 #define isdecGCmodegen(g)	(g->gckind == KGC_GEN || g->lastatomic != 0)
 
+
+/*
+** Control when GC is running:
+*/
+#define GCSTPUSR	1  /* bit true when GC stopped by user */
+#define GCSTPGC		2  /* bit true when GC stopped by itself */
+#define GCSTPCLS	4  /* bit true when closing Lua state */
+#define gcrunning(g)	((g)->gcstp == 0)
+
+
 /*
 ** Does one step of collection when debt becomes positive. 'pre'/'pos'
 ** allows some adjustments to be done only when needed. macro
diff --git a/contrib/lua/src/liolib.c b/contrib/lua/src/liolib.c
index 60ab1bfab64f..b08397da45da 100644
--- a/contrib/lua/src/liolib.c
+++ b/contrib/lua/src/liolib.c
@@ -52,12 +52,6 @@ static int l_checkmode (const char *mode) {
 ** =======================================================
 */
 
-#if !defined(l_checkmodep)
-/* By default, Lua accepts only "r" or "w" as mode */
-#define l_checkmodep(m)	((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
-#endif
-
-
 #if !defined(l_popen)		/* { */
 
 #if defined(LUA_USE_POSIX)	/* { */
@@ -70,6 +64,12 @@ static int l_checkmode (const char *mode) {
 #define l_popen(L,c,m)		(_popen(c,m))
 #define l_pclose(L,file)	(_pclose(file))
 
+#if !defined(l_checkmodep)
+/* Windows accepts "[rw][bt]?" as valid modes */
+#define l_checkmodep(m)	((m[0] == 'r' || m[0] == 'w') && \
+  (m[1] == '\0' || ((m[1] == 'b' || m[1] == 't') && m[2] == '\0')))
+#endif
+
 #else				/* }{ */
 
 /* ISO C definitions */
@@ -83,6 +83,12 @@ static int l_checkmode (const char *mode) {
 
 #endif				/* } */
 
+
+#if !defined(l_checkmodep)
+/* By default, Lua accepts only "r" or "w" as valid modes */
+#define l_checkmodep(m)        ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
+#endif
+
 /* }====================================================== */
 
 
@@ -180,7 +186,7 @@ static int f_tostring (lua_State *L) {
 
 static FILE *tofile (lua_State *L) {
   LStream *p = tolstream(L);
-  if (isclosed(p))
+  if (l_unlikely(isclosed(p)))
     luaL_error(L, "attempt to use a closed file");
   lua_assert(p->f);
   return p->f;
@@ -255,7 +261,7 @@ static LStream *newfile (lua_State *L) {
 static void opencheck (lua_State *L, const char *fname, const char *mode) {
   LStream *p = newfile(L);
   p->f = fopen(fname, mode);
-  if (p->f == NULL)
+  if (l_unlikely(p->f == NULL))
     luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno));
 }
 
@@ -303,7 +309,7 @@ static FILE *getiofile (lua_State *L, const char *findex) {
   LStream *p;
   lua_getfield(L, LUA_REGISTRYINDEX, findex);
   p = (LStream *)lua_touserdata(L, -1);
-  if (isclosed(p))
+  if (l_unlikely(isclosed(p)))
     luaL_error(L, "default %s file is closed", findex + IOPREF_LEN);
   return p->f;
 }
@@ -430,7 +436,7 @@ typedef struct {
 ** Add current char to buffer (if not out of space) and read next one
 */
 static int nextc (RN *rn) {
-  if (rn->n >= L_MAXLENNUM) {  /* buffer overflow? */
+  if (l_unlikely(rn->n >= L_MAXLENNUM)) {  /* buffer overflow? */
     rn->buff[0] = '\0';  /* invalidate result */
     return 0;  /* fail */
   }
@@ -493,8 +499,8 @@ static int read_number (lua_State *L, FILE *f) {
   ungetc(rn.c, rn.f);  /* unread look-ahead char */
   l_unlockfile(rn.f);
   rn.buff[rn.n] = '\0';  /* finish string */
-  if (lua_stringtonumber(L, rn.buff))  /* is this a valid number? */
-    return 1;  /* ok */
+  if (l_likely(lua_stringtonumber(L, rn.buff)))
+    return 1;  /* ok, it is a valid number */
   else {  /* invalid format */
    lua_pushnil(L);  /* "result" to be removed */
    return 0;  /* read fails */
@@ -670,7 +676,8 @@ static int g_write (lua_State *L, FILE *f, int arg) {
       status = status && (fwrite(s, sizeof(char), l, f) == l);
     }
   }
-  if (status) return 1;  /* file handle already on stack top */
+  if (l_likely(status))
+    return 1;  /* file handle already on stack top */
   else return luaL_fileresult(L, status, NULL);
 }
 
@@ -697,7 +704,7 @@ static int f_seek (lua_State *L) {
   luaL_argcheck(L, (lua_Integer)offset == p3, 3,
                   "not an integer in proper range");
   op = l_fseek(f, offset, mode[op]);
-  if (op)
+  if (l_unlikely(op))
     return luaL_fileresult(L, 0, NULL);  /* error */
   else {
     lua_pushinteger(L, (lua_Integer)l_ftell(f));
diff --git a/contrib/lua/src/llex.c b/contrib/lua/src/llex.c
index 4b8dec99859a..e99151787a63 100644
--- a/contrib/lua/src/llex.c
+++ b/contrib/lua/src/llex.c
@@ -122,26 +122,29 @@ l_noret luaX_syntaxerror (LexState *ls, const char *msg) {
 
 
 /*
-** creates a new string and anchors it in scanner's table so that
-** it will not be collected until the end of the compilation
-** (by that time it should be anchored somewhere)
+** Creates a new string and anchors it in scanner's table so that it
+** will not be collected until the end of the compilation; by that time
+** it should be anchored somewhere. It also internalizes long strings,
+** ensuring there is only one copy of each unique string.  The table
+** here is used as a set: the string enters as the key, while its value
+** is irrelevant. We use the string itself as the value only because it
+** is a TValue readly available. Later, the code generation can change
+** this value.
 */
 TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
   lua_State *L = ls->L;
-  TValue *o;  /* entry for 'str' */
   TString *ts = luaS_newlstr(L, str, l);  /* create new string */
-  setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
-  o = luaH_set(L, ls->h, s2v(L->top - 1));
-  if (isempty(o)) {  /* not in use yet? */
-    /* boolean value does not need GC barrier;
-       table is not a metatable, so it does not need to invalidate cache */
-    setbtvalue(o);  /* t[string] = true */
+  const TValue *o = luaH_getstr(ls->h, ts);
+  if (!ttisnil(o))  /* string already present? */
+    ts = keystrval(nodefromval(o));  /* get saved copy */
+  else {  /* not in use yet */
+    TValue *stv = s2v(L->top++);  /* reserve stack space for string */
+    setsvalue(L, stv, ts);  /* temporarily anchor the string */
+    luaH_finishset(L, ls->h, stv, o, stv);  /* t[string] = string */
+    /* table is not a metatable, so it does not need to invalidate cache */
     luaC_checkGC(L);
+    L->top--;  /* remove string from stack */
   }
-  else {  /* string already present */
-    ts = keystrval(nodefromval(o));  /* re-use value previously stored */
-  }
-  L->top--;  /* remove string from stack */
   return ts;
 }
 
diff --git a/contrib/lua/src/llimits.h b/contrib/lua/src/llimits.h
index d03948314f5c..52a32f92e302 100644
--- a/contrib/lua/src/llimits.h
+++ b/contrib/lua/src/llimits.h
@@ -150,35 +150,33 @@ typedef LUAI_UACINT l_uacInt;
 
 
 /*
-** macros to improve jump prediction (used mainly for error handling)
+** non-return type
 */
-#if !defined(likely)
+#if !defined(l_noret)
 
 #if defined(__GNUC__)
-#define likely(x)	(__builtin_expect(((x) != 0), 1))
-#define unlikely(x)	(__builtin_expect(((x) != 0), 0))
+#define l_noret		void __attribute__((noreturn))
+#elif defined(_MSC_VER) && _MSC_VER >= 1200
+#define l_noret		void __declspec(noreturn)
 #else
-#define likely(x)	(x)
-#define unlikely(x)	(x)
+#define l_noret		void
 #endif
 
 #endif
 
 
 /*
-** non-return type
+** Inline functions
 */
-#if !defined(l_noret)
-
-#if defined(__GNUC__)
-#define l_noret		void __attribute__((noreturn))
-#elif defined(_MSC_VER) && _MSC_VER >= 1200
-#define l_noret		void __declspec(noreturn)
+#if !defined(LUA_USE_C89)
+#define l_inline	inline
+#elif defined(__GNUC__)
+#define l_inline	__inline__
 #else
-#define l_noret		void
+#define l_inline	/* empty */
 #endif
 
-#endif
+#define l_sinline	static l_inline
 
 
 /*
@@ -363,7 +361,7 @@ typedef l_uint32 Instruction;
 #define condchangemem(L,pre,pos)	((void)0)
 #else
 #define condchangemem(L,pre,pos)  \
-	{ if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } }
+	{ if (gcrunning(G(L))) { pre; luaC_fullgc(L, 0); pos; } }
 #endif
 
 #endif
diff --git a/contrib/lua/src/lmathlib.c b/contrib/lua/src/lmathlib.c
index 86def470c44e..e0c61a168d98 100644
--- a/contrib/lua/src/lmathlib.c
+++ b/contrib/lua/src/lmathlib.c
@@ -73,7 +73,7 @@ static int math_atan (lua_State *L) {
 static int math_toint (lua_State *L) {
   int valid;
   lua_Integer n = lua_tointegerx(L, 1, &valid);
-  if (valid)
+  if (l_likely(valid))
     lua_pushinteger(L, n);
   else {
     luaL_checkany(L, 1);
@@ -175,7 +175,8 @@ static int math_log (lua_State *L) {
     lua_Number base = luaL_checknumber(L, 2);
 #if !defined(LUA_USE_C89)
     if (base == l_mathop(2.0))
-      res = l_mathop(log2)(x); else
+      res = l_mathop(log2)(x);
+    else
 #endif
     if (base == l_mathop(10.0))
       res = l_mathop(log10)(x);
@@ -474,7 +475,7 @@ static lua_Number I2d (Rand64 x) {
 
 /* 2^(-FIGS) = 1.0 / 2^30 / 2^3 / 2^(FIGS-33) */
 #define scaleFIG  \
-	((lua_Number)1.0 / (UONE << 30) / 8.0 / (UONE << (FIGS - 33)))
+    (l_mathop(1.0) / (UONE << 30) / l_mathop(8.0) / (UONE << (FIGS - 33)))
 
 /*
 ** use FIGS - 32 bits from lower half, throwing out the other
@@ -485,7 +486,7 @@ static lua_Number I2d (Rand64 x) {
 /*
 ** higher 32 bits go after those (FIGS - 32) bits: shiftHI = 2^(FIGS - 32)
 */
-#define shiftHI		((lua_Number)(UONE << (FIGS - 33)) * 2.0)
+#define shiftHI		((lua_Number)(UONE << (FIGS - 33)) * l_mathop(2.0))
 
 
 static lua_Number I2d (Rand64 x) {
diff --git a/contrib/lua/src/lmem.c b/contrib/lua/src/lmem.c
index 43739bffd1d0..9029d588c12e 100644
--- a/contrib/lua/src/lmem.c
+++ b/contrib/lua/src/lmem.c
@@ -24,12 +24,12 @@
 
 #if defined(EMERGENCYGCTESTS)
 /*
-** First allocation will fail whenever not building initial state
-** and not shrinking a block. (This fail will trigger 'tryagain' and
-** a full GC cycle at every allocation.)
+** First allocation will fail whenever not building initial state.
+** (This fail will trigger 'tryagain' and a full GC cycle at every
+** allocation.)
 */
 static void *firsttry (global_State *g, void *block, size_t os, size_t ns) {
-  if (ttisnil(&g->nilvalue) && ns > os)
+  if (completestate(g) && ns > 0)  /* frees never fail */
     return NULL;  /* fail */
   else  /* normal allocation */
     return (*g->frealloc)(g->ud, block, os, ns);
@@ -83,7 +83,7 @@ void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize,
   if (nelems + 1 <= size)  /* does one extra element still fit? */
     return block;  /* nothing to be done */
   if (size >= limit / 2) {  /* cannot double it? */
-    if (unlikely(size >= limit))  /* cannot grow even a little? */
+    if (l_unlikely(size >= limit))  /* cannot grow even a little? */
       luaG_runerror(L, "too many %s (limit is %d)", what, limit);
     size = limit;  /* still have at least one free place */
   }
@@ -138,15 +138,17 @@ void luaM_free_ (lua_State *L, void *block, size_t osize) {
 
 
 /*
-** In case of allocation fail, this function will call the GC to try
-** to free some memory and then try the allocation again.
-** (It should not be called when shrinking a block, because then the
-** interpreter may be in the middle of a collection step.)
+** In case of allocation fail, this function will do an emergency
+** collection to free some memory and then try the allocation again.
+** The GC should not be called while state is not fully built, as the
+** collector is not yet fully initialized. Also, it should not be called
+** when 'gcstopem' is true, because then the interpreter is in the
+** middle of a collection step.
 */
 static void *tryagain (lua_State *L, void *block,
                        size_t osize, size_t nsize) {
   global_State *g = G(L);
-  if (ttisnil(&g->nilvalue)) {  /* is state fully build? */
+  if (completestate(g) && !g->gcstopem) {
     luaC_fullgc(L, 1);  /* try to free some memory... */
     return (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
   }
@@ -156,17 +158,14 @@ static void *tryagain (lua_State *L, void *block,
 
 /*
 ** Generic allocation routine.
-** If allocation fails while shrinking a block, do not try again; the
-** GC shrinks some blocks and it is not reentrant.
 */
 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
   void *newblock;
   global_State *g = G(L);
   lua_assert((osize == 0) == (block == NULL));
   newblock = firsttry(g, block, osize, nsize);
-  if (unlikely(newblock == NULL && nsize > 0)) {
-    if (nsize > osize)  /* not shrinking a block? */
-      newblock = tryagain(L, block, osize, nsize);
+  if (l_unlikely(newblock == NULL && nsize > 0)) {
+    newblock = tryagain(L, block, osize, nsize);
     if (newblock == NULL)  /* still no memory? */
       return NULL;  /* do not update 'GCdebt' */
   }
@@ -179,7 +178,7 @@ void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
 void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize,
                                                     size_t nsize) {
   void *newblock = luaM_realloc_(L, block, osize, nsize);
-  if (unlikely(newblock == NULL && nsize > 0))  /* allocation failed? */
+  if (l_unlikely(newblock == NULL && nsize > 0))  /* allocation failed? */
     luaM_error(L);
   return newblock;
 }
@@ -191,7 +190,7 @@ void *luaM_malloc_ (lua_State *L, size_t size, int tag) {
   else {
     global_State *g = G(L);
     void *newblock = firsttry(g, NULL, tag, size);
-    if (unlikely(newblock == NULL)) {
+    if (l_unlikely(newblock == NULL)) {
       newblock = tryagain(L, NULL, tag, size);
       if (newblock == NULL)
         luaM_error(L);
diff --git a/contrib/lua/src/loadlib.c b/contrib/lua/src/loadlib.c
index c0ec9a131b50..6f9fa37366e4 100644
--- a/contrib/lua/src/loadlib.c
+++ b/contrib/lua/src/loadlib.c
@@ -132,14 +132,16 @@ static void lsys_unloadlib (void *lib) {
 
 static void *lsys_load (lua_State *L, const char *path, int seeglb) {
   void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
-  if (lib == NULL) lua_pushstring(L, dlerror());
+  if (l_unlikely(lib == NULL))
+    lua_pushstring(L, dlerror());
   return lib;
 }
 
 
 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
   lua_CFunction f = cast_func(dlsym(lib, sym));
-  if (f == NULL) lua_pushstring(L, dlerror());
+  if (l_unlikely(f == NULL))
+    lua_pushstring(L, dlerror());
   return f;
 }
 
@@ -410,7 +412,7 @@ static int ll_loadlib (lua_State *L) {
   const char *path = luaL_checkstring(L, 1);
   const char *init = luaL_checkstring(L, 2);
   int stat = lookforfunc(L, path, init);
-  if (stat == 0)  /* no errors? */
+  if (l_likely(stat == 0))  /* no errors? */
     return 1;  /* return the loaded function */
   else {  /* error; error message is on stack top */
     luaL_pushfail(L);
@@ -523,14 +525,14 @@ static const char *findfile (lua_State *L, const char *name,
   const char *path;
   lua_getfield(L, lua_upvalueindex(1), pname);
   path = lua_tostring(L, -1);
-  if (path == NULL)
+  if (l_unlikely(path == NULL))
     luaL_error(L, "'package.%s' must be a string", pname);
   return searchpath(L, name, path, ".", dirsep);
 }
 
 
 static int checkload (lua_State *L, int stat, const char *filename) {
-  if (stat) {  /* module loaded successfully? */
+  if (l_likely(stat)) {  /* module loaded successfully? */
     lua_pushstring(L, filename);  /* will be 2nd argument to module */
     return 2;  /* return open function and file name */
   }
@@ -623,13 +625,14 @@ static void findloader (lua_State *L, const char *name) {
   int i;
   luaL_Buffer msg;  /* to build error message */
   /* push 'package.searchers' to index 3 in the stack */
-  if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
+  if (l_unlikely(lua_getfield(L, lua_upvalueindex(1), "searchers")
+                 != LUA_TTABLE))
     luaL_error(L, "'package.searchers' must be a table");
   luaL_buffinit(L, &msg);
   /*  iterate over available searchers to find a loader */
   for (i = 1; ; i++) {
     luaL_addstring(&msg, "\n\t");  /* error-message prefix */
-    if (lua_rawgeti(L, 3, i) == LUA_TNIL) {  /* no more searchers? */
+    if (l_unlikely(lua_rawgeti(L, 3, i) == LUA_TNIL)) {  /* no more searchers? */
       lua_pop(L, 1);  /* remove nil */
       luaL_buffsub(&msg, 2);  /* remove prefix */
       luaL_pushresult(&msg);  /* create error message */
diff --git a/contrib/lua/src/lobject.c b/contrib/lua/src/lobject.c
index 0e504be03e87..301aa900be0a 100644
--- a/contrib/lua/src/lobject.c
+++ b/contrib/lua/src/lobject.c
@@ -164,7 +164,7 @@ static int isneg (const char **s) {
 */
 static lua_Number lua_strx2number (const char *s, char **endptr) {
   int dot = lua_getlocaledecpoint();
-  lua_Number r = 0.0;  /* result (accumulator) */
+  lua_Number r = l_mathop(0.0);  /* result (accumulator) */
   int sigdig = 0;  /* number of significant digits */
   int nosigdig = 0;  /* number of non-significant digits */
   int e = 0;  /* exponent correction */
@@ -174,7 +174,7 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
   neg = isneg(&s);  /* check sign */
   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
-    return 0.0;  /* invalid format (no '0x') */
+    return l_mathop(0.0);  /* invalid format (no '0x') */
   for (s += 2; ; s++) {  /* skip '0x' and read numeral */
     if (*s == dot) {
       if (hasdot) break;  /* second dot? stop loop */
@@ -184,14 +184,14 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
       if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
         nosigdig++;
       else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
-          r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
+          r = (r * l_mathop(16.0)) + luaO_hexavalue(*s);
       else e++; /* too many digits; ignore, but still count for exponent */
       if (hasdot) e--;  /* decimal digit? correct exponent */
     }
     else break;  /* neither a dot nor a digit */
   }
   if (nosigdig + sigdig == 0)  /* no digits? */
-    return 0.0;  /* invalid format */
+    return l_mathop(0.0);  /* invalid format */
   *endptr = cast_charp(s);  /* valid up to here */
   e *= 4;  /* each digit multiplies/divides value by 2^4 */
   if (*s == 'p' || *s == 'P') {  /* exponent part? */
@@ -200,7 +200,7 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
     s++;  /* skip 'p' */
     neg1 = isneg(&s);  /* sign */
     if (!lisdigit(cast_uchar(*s)))
-      return 0.0;  /* invalid; must have at least one digit */
+      return l_mathop(0.0);  /* invalid; must have at least one digit */
     while (lisdigit(cast_uchar(*s)))  /* read exponent */
       exp1 = exp1 * 10 + *(s++) - '0';
     if (neg1) exp1 = -exp1;
diff --git a/contrib/lua/src/lobject.h b/contrib/lua/src/lobject.h
index 1cc8e757bf16..0e05b3e42ea9 100644
--- a/contrib/lua/src/lobject.h
+++ b/contrib/lua/src/lobject.h
@@ -68,7 +68,7 @@ typedef struct TValue {
 
 
 #define val_(o)		((o)->value_)
-#define valraw(o)	(&val_(o))
+#define valraw(o)	(val_(o))
 
 
 /* raw type tag of a TValue */
@@ -112,7 +112,7 @@ typedef struct TValue {
 #define settt_(o,t)	((o)->tt_=(t))
 
 
-/* main macro to copy values (from 'obj1' to 'obj2') */
+/* main macro to copy values (from 'obj2' to 'obj1') */
 #define setobj(L,obj1,obj2) \
 	{ TValue *io1=(obj1); const TValue *io2=(obj2); \
           io1->value_ = io2->value_; settt_(io1, io2->tt_); \
@@ -136,10 +136,19 @@ typedef struct TValue {
 
 
 /*
-** Entries in the Lua stack
+** Entries in a Lua stack. Field 'tbclist' forms a list of all
+** to-be-closed variables active in this stack. Dummy entries are
+** used when the distance between two tbc variables does not fit
+** in an unsigned short. They are represented by delta==0, and
+** their real delta is always the maximum value that fits in
+** that field.
 */
 typedef union StackValue {
   TValue val;
+  struct {
+    TValuefields;
+    unsigned short delta;
+  } tbclist;
 } StackValue;
 
 
@@ -570,10 +579,11 @@ typedef struct Proto {
 #define LUA_VCCL	makevariant(LUA_TFUNCTION, 2)  /* C closure */
 
 #define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
-#define ttisclosure(o)		((rawtt(o) & 0x1F) == LUA_VLCL)
 #define ttisLclosure(o)		checktag((o), ctb(LUA_VLCL))
 #define ttislcf(o)		checktag((o), LUA_VLCF)
 #define ttisCclosure(o)		checktag((o), ctb(LUA_VCCL))
+#define ttisclosure(o)         (ttisLclosure(o) || ttisCclosure(o))
+
 
 #define isLfunction(o)	ttisLclosure(o)
 
diff --git a/contrib/lua/src/lopcodes.h b/contrib/lua/src/lopcodes.h
index 120cdd94383c..7c2745159606 100644
--- a/contrib/lua/src/lopcodes.h
+++ b/contrib/lua/src/lopcodes.h
@@ -190,7 +190,8 @@ enum OpMode {iABC, iABx, iAsBx, iAx, isJ};  /* basic instruction formats */
 
 
 /*
-** grep "ORDER OP" if you change these enums
+** Grep "ORDER OP" if you change these enums. Opcodes marked with a (*)
+** has extra descriptions in the notes after the enumeration.
 */
 
 typedef enum {
@@ -203,7 +204,7 @@ OP_LOADF,/*	A sBx	R[A] := (lua_Number)sBx				*/
 OP_LOADK,/*	A Bx	R[A] := K[Bx]					*/
 OP_LOADKX,/*	A	R[A] := K[extra arg]				*/
 OP_LOADFALSE,/*	A	R[A] := false					*/
-OP_LFALSESKIP,/*A	R[A] := false; pc++				*/
+OP_LFALSESKIP,/*A	R[A] := false; pc++	(*)			*/
 OP_LOADTRUE,/*	A	R[A] := true					*/
 OP_LOADNIL,/*	A B	R[A], R[A+1], ..., R[A+B] := nil		*/
 OP_GETUPVAL,/*	A B	R[A] := UpValue[B]				*/
@@ -225,13 +226,13 @@ OP_SELF,/*	A B C	R[A+1] := R[B]; R[A] := R[B][RK(C):string]	*/
 
 OP_ADDI,/*	A B sC	R[A] := R[B] + sC				*/
 
-OP_ADDK,/*	A B C	R[A] := R[B] + K[C]				*/
-OP_SUBK,/*	A B C	R[A] := R[B] - K[C]				*/
-OP_MULK,/*	A B C	R[A] := R[B] * K[C]				*/
-OP_MODK,/*	A B C	R[A] := R[B] % K[C]				*/
-OP_POWK,/*	A B C	R[A] := R[B] ^ K[C]				*/
-OP_DIVK,/*	A B C	R[A] := R[B] / K[C]				*/
-OP_IDIVK,/*	A B C	R[A] := R[B] // K[C]				*/
+OP_ADDK,/*	A B C	R[A] := R[B] + K[C]:number			*/
+OP_SUBK,/*	A B C	R[A] := R[B] - K[C]:number			*/
+OP_MULK,/*	A B C	R[A] := R[B] * K[C]:number			*/
+OP_MODK,/*	A B C	R[A] := R[B] % K[C]:number			*/
+OP_POWK,/*	A B C	R[A] := R[B] ^ K[C]:number			*/
+OP_DIVK,/*	A B C	R[A] := R[B] / K[C]:number			*/
+OP_IDIVK,/*	A B C	R[A] := R[B] // K[C]:number			*/
 
 OP_BANDK,/*	A B C	R[A] := R[B] & K[C]:integer			*/
 OP_BORK,/*	A B C	R[A] := R[B] | K[C]:integer			*/
@@ -254,7 +255,7 @@ OP_BXOR,/*	A B C	R[A] := R[B] ~ R[C]				*/
 OP_SHL,/*	A B C	R[A] := R[B] << R[C]				*/
 OP_SHR,/*	A B C	R[A] := R[B] >> R[C]				*/
 
-OP_MMBIN,/*	A B C	call C metamethod over R[A] and R[B]		*/
+OP_MMBIN,/*	A B C	call C metamethod over R[A] and R[B]	(*)	*/
 OP_MMBINI,/*	A sB C k	call C metamethod over R[A] and sB	*/
 OP_MMBINK,/*	A B C k		call C metamethod over R[A] and K[B]	*/
 
@@ -280,7 +281,7 @@ OP_GTI,/*	A sB k	if ((R[A] > sB) ~= k) then pc++			*/
 OP_GEI,/*	A sB k	if ((R[A] >= sB) ~= k) then pc++		*/
 
 OP_TEST,/*	A k	if (not R[A] == k) then pc++			*/
-OP_TESTSET,/*	A B k	if (not R[B] == k) then pc++ else R[A] := R[B]	*/
+OP_TESTSET,/*	A B k	if (not R[B] == k) then pc++ else R[A] := R[B] (*) */
 
 OP_CALL,/*	A B C	R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
 OP_TAILCALL,/*	A B C k	return R[A](R[A+1], ... ,R[A+B-1])		*/
@@ -315,6 +316,18 @@ OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
 
 /*===========================================================================
   Notes:
+
+  (*) Opcode OP_LFALSESKIP is used to convert a condition to a boolean
+  value, in a code equivalent to (not cond ? false : true).  (It
+  produces false and skips the next instruction producing true.)
+
+  (*) Opcodes OP_MMBIN and variants follow each arithmetic and
+  bitwise opcode. If the operation succeeds, it skips this next
+  opcode. Otherwise, this opcode calls the corresponding metamethod.
+
+  (*) Opcode OP_TESTSET is used in short-circuit expressions that need
+  both to jump and to produce a value, such as (a = b or c).
+
   (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
   'top' is set to last_result+1, so next open instruction (OP_CALL,
   OP_RETURN*, OP_SETLIST) may use 'top'.
diff --git a/contrib/lua/src/loslib.c b/contrib/lua/src/loslib.c
index e65e188bd727..3e20d622bacd 100644
--- a/contrib/lua/src/loslib.c
+++ b/contrib/lua/src/loslib.c
@@ -170,7 +170,7 @@ static int os_tmpname (lua_State *L) {
   char buff[LUA_TMPNAMBUFSIZE];
   int err;
   lua_tmpnam(buff, err);
-  if (err)
+  if (l_unlikely(err))
     return luaL_error(L, "unable to generate a unique filename");
   lua_pushstring(L, buff);
   return 1;
@@ -208,7 +208,7 @@ static int os_clock (lua_State *L) {
 */
 static void setfield (lua_State *L, const char *key, int value, int delta) {
   #if (defined(LUA_NUMTIME) && LUA_MAXINTEGER <= INT_MAX)
-    if (value > LUA_MAXINTEGER - delta)
+    if (l_unlikely(value > LUA_MAXINTEGER - delta))
       luaL_error(L, "field '%s' is out-of-bound", key);
   #endif
   lua_pushinteger(L, (lua_Integer)value + delta);
@@ -253,9 +253,9 @@ static int getfield (lua_State *L, const char *key, int d, int delta) {
   int t = lua_getfield(L, -1, key);  /* get field and its type */
   lua_Integer res = lua_tointegerx(L, -1, &isnum);
   if (!isnum) {  /* field is not an integer? */
-    if (t != LUA_TNIL)  /* some other value? */
+    if (l_unlikely(t != LUA_TNIL))  /* some other value? */
       return luaL_error(L, "field '%s' is not an integer", key);
-    else if (d < 0)  /* absent field; no default? */
+    else if (l_unlikely(d < 0))  /* absent field; no default? */
       return luaL_error(L, "field '%s' missing in date table", key);
     res = d;
   }
diff --git a/contrib/lua/src/lparser.c b/contrib/lua/src/lparser.c
index 77813a74e942..3abe3d75187b 100644
--- a/contrib/lua/src/lparser.c
+++ b/contrib/lua/src/lparser.c
@@ -128,7 +128,7 @@ static void checknext (LexState *ls, int c) {
 ** in line 'where' (if that is not the current line).
 */
 static void check_match (LexState *ls, int what, int who, int where) {
-  if (unlikely(!testnext(ls, what))) {
+  if (l_unlikely(!testnext(ls, what))) {
     if (where == ls->linenumber)  /* all in the same line? */
       error_expected(ls, what);  /* do not need a complex message */
     else {
@@ -222,26 +222,26 @@ static Vardesc *getlocalvardesc (FuncState *fs, int vidx) {
 
 
 /*
-** Convert 'nvar', a compiler index level, to it corresponding
-** stack index level. For that, search for the highest variable
-** below that level that is in the stack and uses its stack
-** index ('sidx').
+** Convert 'nvar', a compiler index level, to its corresponding
+** register. For that, search for the highest variable below that level
+** that is in a register and uses its register index ('ridx') plus one.
 */
-static int stacklevel (FuncState *fs, int nvar) {
+static int reglevel (FuncState *fs, int nvar) {
   while (nvar-- > 0) {
-    Vardesc *vd = getlocalvardesc(fs, nvar);  /* get variable */
-    if (vd->vd.kind != RDKCTC)  /* is in the stack? */
-      return vd->vd.sidx + 1;
+    Vardesc *vd = getlocalvardesc(fs, nvar);  /* get previous variable */
+    if (vd->vd.kind != RDKCTC)  /* is in a register? */
+      return vd->vd.ridx + 1;
   }
-  return 0;  /* no variables in the stack */
+  return 0;  /* no variables in registers */
 }
 
 
 /*
-** Return the number of variables in the stack for function 'fs'
+** Return the number of variables in the register stack for the given
+** function.
 */
 int luaY_nvarstack (FuncState *fs) {
-  return stacklevel(fs, fs->nactvar);
+  return reglevel(fs, fs->nactvar);
 }
 
 
@@ -267,7 +267,7 @@ static void init_var (FuncState *fs, expdesc *e, int vidx) {
   e->f = e->t = NO_JUMP;
   e->k = VLOCAL;
   e->u.var.vidx = vidx;
-  e->u.var.sidx = getlocalvardesc(fs, vidx)->vd.sidx;
+  e->u.var.ridx = getlocalvardesc(fs, vidx)->vd.ridx;
 }
 
 
@@ -310,12 +310,12 @@ static void check_readonly (LexState *ls, expdesc *e) {
 */
 static void adjustlocalvars (LexState *ls, int nvars) {
   FuncState *fs = ls->fs;
-  int stklevel = luaY_nvarstack(fs);
+  int reglevel = luaY_nvarstack(fs);
   int i;
   for (i = 0; i < nvars; i++) {
     int vidx = fs->nactvar++;
     Vardesc *var = getlocalvardesc(fs, vidx);
-    var->vd.sidx = stklevel++;
+    var->vd.ridx = reglevel++;
     var->vd.pidx = registerlocalvar(ls, fs, var->vd.name);
   }
 }
@@ -366,7 +366,7 @@ static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
   FuncState *prev = fs->prev;
   if (v->k == VLOCAL) {
     up->instack = 1;
-    up->idx = v->u.var.sidx;
+    up->idx = v->u.var.ridx;
     up->kind = getlocalvardesc(prev, v->u.var.vidx)->vd.kind;
     lua_assert(eqstr(name, getlocalvardesc(prev, v->u.var.vidx)->vd.name));
   }
@@ -417,6 +417,17 @@ static void markupval (FuncState *fs, int level) {
 
 
 /*
+** Mark that current block has a to-be-closed variable.
+*/
+static void marktobeclosed (FuncState *fs) {
+  BlockCnt *bl = fs->bl;
+  bl->upval = 1;
+  bl->insidetbc = 1;
+  fs->needclose = 1;
+}
+
+
+/*
 ** Find a variable with the given name 'n'. If it is an upvalue, add
 ** this upvalue into all intermediate functions. If it is a global, set
 ** 'var' as 'void' as a flag.
@@ -517,7 +528,7 @@ static void solvegoto (LexState *ls, int g, Labeldesc *label) {
   Labellist *gl = &ls->dyd->gt;  /* list of goto's */
   Labeldesc *gt = &gl->arr[g];  /* goto to be resolved */
   lua_assert(eqstr(gt->name, label->name));
-  if (unlikely(gt->nactvar < label->nactvar))  /* enter some scope? */
+  if (l_unlikely(gt->nactvar < label->nactvar))  /* enter some scope? */
     jumpscopeerror(ls, gt);
   luaK_patchlist(ls->fs, gt->pc, label->pc);
   for (i = g; i < gl->n - 1; i++)  /* remove goto from pending list */
@@ -620,7 +631,7 @@ static void movegotosout (FuncState *fs, BlockCnt *bl) {
   for (i = bl->firstgoto; i < gl->n; i++) {  /* for each pending goto */
     Labeldesc *gt = &gl->arr[i];
     /* leaving a variable scope? */
-    if (stacklevel(fs, gt->nactvar) > stacklevel(fs, bl->nactvar))
+    if (reglevel(fs, gt->nactvar) > reglevel(fs, bl->nactvar))
       gt->close |= bl->upval;  /* jump may need a close */
     gt->nactvar = bl->nactvar;  /* update goto level */
   }
@@ -661,7 +672,7 @@ static void leaveblock (FuncState *fs) {
   BlockCnt *bl = fs->bl;
   LexState *ls = fs->ls;
   int hasclose = 0;
-  int stklevel = stacklevel(fs, bl->nactvar);  /* level outside the block */
+  int stklevel = reglevel(fs, bl->nactvar);  /* level outside the block */
   if (bl->isloop)  /* fix pending breaks? */
     hasclose = createlabel(ls, luaS_newliteral(ls->L, "break"), 0, 0);
   if (!hasclose && bl->previous && bl->upval)
@@ -1330,13 +1341,13 @@ static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
         }
       }
       else {  /* table is a register */
-        if (v->k == VLOCAL && lh->v.u.ind.t == v->u.var.sidx) {
+        if (v->k == VLOCAL && lh->v.u.ind.t == v->u.var.ridx) {
           conflict = 1;  /* table is the local being assigned now */
           lh->v.u.ind.t = extra;  /* assignment will use safe copy */
         }
         /* is index the local being assigned? */
         if (lh->v.k == VINDEXED && v->k == VLOCAL &&
-            lh->v.u.ind.idx == v->u.var.sidx) {
+            lh->v.u.ind.idx == v->u.var.ridx) {
           conflict = 1;
           lh->v.u.ind.idx = extra;  /* previous assignment will use safe copy */
         }
@@ -1346,7 +1357,7 @@ static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
   if (conflict) {
     /* copy upvalue/local value to a temporary (in position 'extra') */
     if (v->k == VLOCAL)
-      luaK_codeABC(fs, OP_MOVE, extra, v->u.var.sidx, 0);
+      luaK_codeABC(fs, OP_MOVE, extra, v->u.var.ridx, 0);
     else
       luaK_codeABC(fs, OP_GETUPVAL, extra, v->u.info, 0);
     luaK_reserveregs(fs, 1);
@@ -1411,7 +1422,7 @@ static void gotostat (LexState *ls) {
     newgotoentry(ls, name, line, luaK_jump(fs));
   else {  /* found a label */
     /* backward jump; will be resolved here */
-    int lblevel = stacklevel(fs, lb->nactvar);  /* label level */
+    int lblevel = reglevel(fs, lb->nactvar);  /* label level */
     if (luaY_nvarstack(fs) > lblevel)  /* leaving the scope of a variable? */
       luaK_codeABC(fs, OP_CLOSE, lblevel, 0, 0);
     /* create jump and link it to the label */
@@ -1435,7 +1446,7 @@ static void breakstat (LexState *ls) {
 */
 static void checkrepeated (LexState *ls, TString *name) {
   Labeldesc *lb = findlabel(ls, name);
-  if (unlikely(lb != NULL)) {  /* already defined? */
+  if (l_unlikely(lb != NULL)) {  /* already defined? */
     const char *msg = "label '%s' already defined on line %d";
     msg = luaO_pushfstring(ls->L, msg, getstr(name), lb->line);
     luaK_semerror(ls, msg);  /* error */
@@ -1488,7 +1499,7 @@ static void repeatstat (LexState *ls, int line) {
   if (bl2.upval) {  /* upvalues? */
     int exit = luaK_jump(fs);  /* normal exit must jump over fix */
     luaK_patchtohere(fs, condexit);  /* repetition must close upvalues */
-    luaK_codeABC(fs, OP_CLOSE, stacklevel(fs, bl2.nactvar), 0, 0);
+    luaK_codeABC(fs, OP_CLOSE, reglevel(fs, bl2.nactvar), 0, 0);
     condexit = luaK_jump(fs);  /* repeat after closing upvalues */
     luaK_patchtohere(fs, exit);  /* normal exit comes to here */
   }
@@ -1520,7 +1531,7 @@ static void fixforjump (FuncState *fs, int pc, int dest, int back) {
   int offset = dest - (pc + 1);
   if (back)
     offset = -offset;
-  if (unlikely(offset > MAXARG_Bx))
+  if (l_unlikely(offset > MAXARG_Bx))
     luaX_syntaxerror(fs->ls, "control structure too long");
   SETARG_Bx(*jmp, offset);
 }
@@ -1599,7 +1610,7 @@ static void forlist (LexState *ls, TString *indexname) {
   line = ls->linenumber;
   adjust_assign(ls, 4, explist(ls, &e), &e);
   adjustlocalvars(ls, 4);  /* control variables */
-  markupval(fs, fs->nactvar);  /* last control var. must be closed */
+  marktobeclosed(fs);  /* last control var. must be closed */
   luaK_checkstack(fs, 3);  /* extra space to call generator */
   forbody(ls, base, line, nvars - 4, 1);
 }
@@ -1703,12 +1714,10 @@ static int getlocalattribute (LexState *ls) {
 }
 
 
-static void checktoclose (LexState *ls, int level) {
+static void checktoclose (FuncState *fs, int level) {
   if (level != -1) {  /* is there a to-be-closed variable? */
-    FuncState *fs = ls->fs;
-    markupval(fs, level + 1);
-    fs->bl->insidetbc = 1;  /* in the scope of a to-be-closed variable */
-    luaK_codeABC(fs, OP_TBC, stacklevel(fs, level), 0, 0);
+    marktobeclosed(fs);
+    luaK_codeABC(fs, OP_TBC, reglevel(fs, level), 0, 0);
   }
 }
 
@@ -1751,7 +1760,7 @@ static void localstat (LexState *ls) {
     adjust_assign(ls, nvars, nexps, &e);
     adjustlocalvars(ls, nvars);
   }
-  checktoclose(ls, toclose);
+  checktoclose(fs, toclose);
 }
 
 
@@ -1776,6 +1785,7 @@ static void funcstat (LexState *ls, int line) {
   luaX_next(ls);  /* skip FUNCTION */
   ismethod = funcname(ls, &v);
   body(ls, &b, ismethod, line);
+  check_readonly(ls, &v);
   luaK_storevar(ls->fs, &v, &b);
   luaK_fixline(ls->fs, line);  /* definition "happens" in the first line */
 }
diff --git a/contrib/lua/src/lparser.h b/contrib/lua/src/lparser.h
index 2e6dae72f247..5e4500f181a8 100644
--- a/contrib/lua/src/lparser.h
+++ b/contrib/lua/src/lparser.h
@@ -35,7 +35,7 @@ typedef enum {
              (string is fixed by the lexer) */
   VNONRELOC,  /* expression has its value in a fixed register;
                  info = result register */
-  VLOCAL,  /* local variable; var.sidx = stack index (local register);
+  VLOCAL,  /* local variable; var.ridx = register index;
               var.vidx = relative index in 'actvar.arr'  */
   VUPVAL,  /* upvalue variable; info = index of upvalue in 'upvalues' */
   VCONST,  /* compile-time <const> variable;
@@ -77,7 +77,7 @@ typedef struct expdesc {
       lu_byte t;  /* table (register or upvalue) */
     } ind;
     struct {  /* for local variables */
-      lu_byte sidx;  /* index in the stack */
+      lu_byte ridx;  /* register holding the variable */
       unsigned short vidx;  /* compiler index (in 'actvar.arr')  */
     } var;
   } u;
@@ -97,7 +97,7 @@ typedef union Vardesc {
   struct {
     TValuefields;  /* constant value (if it is a compile-time constant) */
     lu_byte kind;
-    lu_byte sidx;  /* index of the variable in the stack */
+    lu_byte ridx;  /* register holding the variable */
     short pidx;  /* index of the variable in the Proto's 'locvars' array */
     TString *name;  /* variable name */
   } vd;
diff --git a/contrib/lua/src/lstate.c b/contrib/lua/src/lstate.c
index 1c7b8791daf8..1ffe1a0f71cd 100644
--- a/contrib/lua/src/lstate.c
+++ b/contrib/lua/src/lstate.c
@@ -166,13 +166,13 @@ void luaE_checkcstack (lua_State *L) {
   if (getCcalls(L) == LUAI_MAXCCALLS)
     luaG_runerror(L, "C stack overflow");
   else if (getCcalls(L) >= (LUAI_MAXCCALLS / 10 * 11))
-    luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
+    luaD_throw(L, LUA_ERRERR);  /* error while handling stack error */
 }
 
 
 LUAI_FUNC void luaE_incCstack (lua_State *L) {
   L->nCcalls++;
-  if (unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
+  if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
     luaE_checkcstack(L);
 }
 
@@ -181,6 +181,7 @@ static void stack_init (lua_State *L1, lua_State *L) {
   int i; CallInfo *ci;
   /* initialize stack array */
   L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, StackValue);
+  L1->tbclist = L1->stack;
   for (i = 0; i < BASIC_STACK_SIZE + EXTRA_STACK; i++)
     setnilvalue(s2v(L1->stack + i));  /* erase new stack */
   L1->top = L1->stack;
@@ -213,24 +214,19 @@ static void freestack (lua_State *L) {
 ** Create registry table and its predefined values
 */
 static void init_registry (lua_State *L, global_State *g) {
-  TValue temp;
   /* create registry */
   Table *registry = luaH_new(L);
   sethvalue(L, &g->l_registry, registry);
   luaH_resize(L, registry, LUA_RIDX_LAST, 0);
   /* registry[LUA_RIDX_MAINTHREAD] = L */
-  setthvalue(L, &temp, L);  /* temp = L */
-  luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &temp);
-  /* registry[LUA_RIDX_GLOBALS] = table of globals */
-  sethvalue(L, &temp, luaH_new(L));  /* temp = new table (global table) */
-  luaH_setint(L, registry, LUA_RIDX_GLOBALS, &temp);
+  setthvalue(L, &registry->array[LUA_RIDX_MAINTHREAD - 1], L);
+  /* registry[LUA_RIDX_GLOBALS] = new table (table of globals) */
+  sethvalue(L, &registry->array[LUA_RIDX_GLOBALS - 1], luaH_new(L));
 }
 
 
 /*
 ** open parts of the state that may cause memory-allocation errors.
-** ('g->nilvalue' being a nil value flags that the state was completely
-** build.)
 */
 static void f_luaopen (lua_State *L, void *ud) {
   global_State *g = G(L);
@@ -240,8 +236,8 @@ static void f_luaopen (lua_State *L, void *ud) {
   luaS_init(L);
   luaT_init(L);
   luaX_init(L);
-  g->gcrunning = 1;  /* allow gc */
-  setnilvalue(&g->nilvalue);
+  g->gcstp = 0;  /* allow gc */
+  setnilvalue(&g->nilvalue);  /* now state is complete */
   luai_userstateopen(L);
 }
 
@@ -256,6 +252,7 @@ static void preinit_thread (lua_State *L, global_State *g) {
   L->ci = NULL;
   L->nci = 0;
   L->twups = L;  /* thread has no upvalues */
+  L->nCcalls = 0;
   L->errorJmp = NULL;
   L->hook = NULL;
   L->hookmask = 0;
@@ -271,10 +268,14 @@ static void preinit_thread (lua_State *L, global_State *g) {
 
 static void close_state (lua_State *L) {
   global_State *g = G(L);
-  luaF_close(L, L->stack, CLOSEPROTECT);  /* close all upvalues */
-  luaC_freeallobjects(L);  /* collect all objects */
-  if (ttisnil(&g->nilvalue))  /* closing a fully built state? */
+  if (!completestate(g))  /* closing a partially built state? */
+    luaC_freeallobjects(L);  /* just collect its objects */
+  else {  /* closing a fully built state */
+    L->ci = &L->base_ci;  /* unwind CallInfo list */
+    luaD_closeprotected(L, 1, LUA_OK);  /* close all upvalues */
+    luaC_freeallobjects(L);  /* collect all objects */
     luai_userstateclose(L);
+  }
   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
   freestack(L);
   lua_assert(gettotalbytes(g) == sizeof(LG));
@@ -299,7 +300,6 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
   setthvalue2s(L, L->top, L1);
   api_incr_top(L);
   preinit_thread(L1, g);
-  L1->nCcalls = 0;
   L1->hookmask = L->hookmask;
   L1->basehookcount = L->basehookcount;
   L1->hook = L->hook;
@@ -316,7 +316,7 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
 
 void luaE_freethread (lua_State *L, lua_State *L1) {
   LX *l = fromstate(L1);
-  luaF_close(L1, L1->stack, NOCLOSINGMETH);  /* close all upvalues */
+  luaF_closeupval(L1, L1->stack);  /* close all upvalues */
   lua_assert(L1->openupval == NULL);
   luai_userstatefree(L, L1);
   freestack(L1);
@@ -324,23 +324,29 @@ void luaE_freethread (lua_State *L, lua_State *L1) {
 }
 
 
-int lua_resetthread (lua_State *L) {
-  CallInfo *ci;
-  int status;
-  lua_lock(L);
-  L->ci = ci = &L->base_ci;  /* unwind CallInfo list */
+int luaE_resetthread (lua_State *L, int status) {
+  CallInfo *ci = L->ci = &L->base_ci;  /* unwind CallInfo list */
   setnilvalue(s2v(L->stack));  /* 'function' entry for basic 'ci' */
   ci->func = L->stack;
   ci->callstatus = CIST_C;
-  status = luaF_close(L, L->stack, CLOSEPROTECT);
-  if (status != CLOSEPROTECT)  /* real errors? */
-    luaD_seterrorobj(L, status, L->stack + 1);
-  else {
+  if (status == LUA_YIELD)
     status = LUA_OK;
+  L->status = LUA_OK;  /* so it can run __close metamethods */
+  status = luaD_closeprotected(L, 1, status);
+  if (status != LUA_OK)  /* errors? */
+    luaD_seterrorobj(L, status, L->stack + 1);
+  else
     L->top = L->stack + 1;
-  }
   ci->top = L->top + LUA_MINSTACK;
-  L->status = status;
+  luaD_reallocstack(L, cast_int(ci->top - L->stack), 0);
+  return status;
+}
+
+
+LUA_API int lua_resetthread (lua_State *L) {
+  int status;
+  lua_lock(L);
+  status = luaE_resetthread(L, L->status);
   lua_unlock(L);
   return status;
 }
@@ -360,7 +366,6 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   preinit_thread(L, g);
   g->allgc = obj2gco(L);  /* by now, only object is the main thread */
   L->next = NULL;
-  L->nCcalls = 0;
   incnny(L);  /* main thread is always non yieldable */
   g->frealloc = f;
   g->ud = ud;
@@ -368,13 +373,14 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   g->ud_warn = NULL;
   g->mainthread = L;
   g->seed = luai_makeseed(L);
-  g->gcrunning = 0;  /* no GC while building state */
+  g->gcstp = GCSTPGC;  /* no GC while building state */
   g->strt.size = g->strt.nuse = 0;
   g->strt.hash = NULL;
   setnilvalue(&g->l_registry);
   g->panic = NULL;
   g->gcstate = GCSpause;
   g->gckind = KGC_INC;
+  g->gcstopem = 0;
   g->gcemergency = 0;
   g->finobj = g->tobefnz = g->fixedgc = NULL;
   g->firstold1 = g->survival = g->old1 = g->reallyold = NULL;
diff --git a/contrib/lua/src/lstate.h b/contrib/lua/src/lstate.h
index cbcf07e203a6..61e82cde7253 100644
--- a/contrib/lua/src/lstate.h
+++ b/contrib/lua/src/lstate.h
@@ -156,6 +156,18 @@ typedef struct stringtable {
 
 /*
 ** Information about a call.
+** About union 'u':
+** - field 'l' is used only for Lua functions;
+** - field 'c' is used only for C functions.
+** About union 'u2':
+** - field 'funcidx' is used only by C functions while doing a
+** protected call;
+** - field 'nyield' is used only while a function is "doing" an
+** yield (from the yield until the next resume);
+** - field 'nres' is used only while closing tbc variables when
+** returning from a function;
+** - field 'transferinfo' is used only during call/returnhooks,
+** before the function starts or after it ends.
 */
 typedef struct CallInfo {
   StkId func;  /* function index in the stack */
@@ -176,6 +188,7 @@ typedef struct CallInfo {
   union {
     int funcidx;  /* called-function index */
     int nyield;  /* number of values yielded */
+    int nres;  /* number of values returned */
     struct {  /* info about transferred values (for call/return hooks) */
       unsigned short ftransfer;  /* offset of first value transferred */
       unsigned short ntransfer;  /* number of values transferred */
@@ -191,17 +204,34 @@ typedef struct CallInfo {
 */
 #define CIST_OAH	(1<<0)	/* original value of 'allowhook' */
 #define CIST_C		(1<<1)	/* call is running a C function */
-#define CIST_FRESH	(1<<2)  /* call is on a fresh "luaV_execute" frame */
+#define CIST_FRESH	(1<<2)	/* call is on a fresh "luaV_execute" frame */
 #define CIST_HOOKED	(1<<3)	/* call is running a debug hook */
-#define CIST_YPCALL	(1<<4)	/* call is a yieldable protected call */
+#define CIST_YPCALL	(1<<4)	/* doing a yieldable protected call */
 #define CIST_TAIL	(1<<5)	/* call was tail called */
 #define CIST_HOOKYIELD	(1<<6)	/* last hook called yielded */
-#define CIST_FIN	(1<<7)  /* call is running a finalizer */
+#define CIST_FIN	(1<<7)	/* function "called" a finalizer */
 #define CIST_TRAN	(1<<8)	/* 'ci' has transfer information */
+#define CIST_CLSRET	(1<<9)  /* function is closing tbc variables */
+/* Bits 10-12 are used for CIST_RECST (see below) */
+#define CIST_RECST	10
 #if defined(LUA_COMPAT_LT_LE)
-#define CIST_LEQ	(1<<9)  /* using __lt for __le */
+#define CIST_LEQ	(1<<13)  /* using __lt for __le */
 #endif
 
+
+/*
+** Field CIST_RECST stores the "recover status", used to keep the error
+** status while closing to-be-closed variables in coroutines, so that
+** Lua can correctly resume after an yield from a __close method called
+** because of an error.  (Three bits are enough for error status.)
+*/
+#define getcistrecst(ci)     (((ci)->callstatus >> CIST_RECST) & 7)
+#define setcistrecst(ci,st)  \
+  check_exp(((st) & 7) == (st),   /* status must fit in three bits */  \
+            ((ci)->callstatus = ((ci)->callstatus & ~(7 << CIST_RECST))  \
+                                                  | ((st) << CIST_RECST)))
+
+
 /* active function is a Lua function */
 #define isLua(ci)	(!((ci)->callstatus & CIST_C))
 
@@ -230,9 +260,10 @@ typedef struct global_State {
   lu_byte currentwhite;
   lu_byte gcstate;  /* state of garbage collector */
   lu_byte gckind;  /* kind of GC running */
+  lu_byte gcstopem;  /* stops emergency collections */
   lu_byte genminormul;  /* control for minor generational collections */
   lu_byte genmajormul;  /* control for major generational collections */
-  lu_byte gcrunning;  /* true if GC is running */
+  lu_byte gcstp;  /* control whether GC is running */
   lu_byte gcemergency;  /* true if this is an emergency collection */
   lu_byte gcpause;  /* size of pause between successive GCs */
   lu_byte gcstepmul;  /* GC "speed" */
@@ -281,6 +312,7 @@ struct lua_State {
   StkId stack_last;  /* end of stack (last element + 1) */
   StkId stack;  /* stack base */
   UpVal *openupval;  /* list of open upvalues in this stack */
+  StkId tbclist;  /* list of to-be-closed variables */
   GCObject *gclist;
   struct lua_State *twups;  /* list of threads with open upvalues */
   struct lua_longjmp *errorJmp;  /* current error recover point */
@@ -297,6 +329,12 @@ struct lua_State {
 
 #define G(L)	(L->l_G)
 
+/*
+** 'g->nilvalue' being a nil value flags that the state was completely
+** build.
+*/
+#define completestate(g)	ttisnil(&g->nilvalue)
+
 
 /*
 ** Union of all collectable objects (only for conversions)
@@ -359,6 +397,7 @@ LUAI_FUNC void luaE_checkcstack (lua_State *L);
 LUAI_FUNC void luaE_incCstack (lua_State *L);
 LUAI_FUNC void luaE_warning (lua_State *L, const char *msg, int tocont);
 LUAI_FUNC void luaE_warnerror (lua_State *L, const char *where);
+LUAI_FUNC int luaE_resetthread (lua_State *L, int status);
 
 
 #endif
diff --git a/contrib/lua/src/lstring.c b/contrib/lua/src/lstring.c
index 138871c70da0..13dcaf4259bc 100644
--- a/contrib/lua/src/lstring.c
+++ b/contrib/lua/src/lstring.c
@@ -89,7 +89,7 @@ void luaS_resize (lua_State *L, int nsize) {
   if (nsize < osize)  /* shrinking table? */
     tablerehash(tb->hash, osize, nsize);  /* depopulate shrinking part */
   newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*);
-  if (unlikely(newvect == NULL)) {  /* reallocation failed? */
+  if (l_unlikely(newvect == NULL)) {  /* reallocation failed? */
     if (nsize < osize)  /* was it shrinking table? */
       tablerehash(tb->hash, nsize, osize);  /* restore to original size */
     /* leave table as it was */
@@ -172,7 +172,7 @@ void luaS_remove (lua_State *L, TString *ts) {
 
 
 static void growstrtab (lua_State *L, stringtable *tb) {
-  if (unlikely(tb->nuse == MAX_INT)) {  /* too many strings? */
+  if (l_unlikely(tb->nuse == MAX_INT)) {  /* too many strings? */
     luaC_fullgc(L, 1);  /* try to free some... */
     if (tb->nuse == MAX_INT)  /* still too many? */
       luaM_error(L);  /* cannot even create a message... */
@@ -223,7 +223,7 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
     return internshrstr(L, str, l);
   else {
     TString *ts;
-    if (unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
+    if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
       luaM_toobig(L);
     ts = luaS_createlngstrobj(L, l);
     memcpy(getstr(ts), str, l * sizeof(char));
@@ -259,7 +259,7 @@ Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) {
   Udata *u;
   int i;
   GCObject *o;
-  if (unlikely(s > MAX_SIZE - udatamemoffset(nuvalue)))
+  if (l_unlikely(s > MAX_SIZE - udatamemoffset(nuvalue)))
     luaM_toobig(L);
   o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s));
   u = gco2u(o);
diff --git a/contrib/lua/src/lstrlib.c b/contrib/lua/src/lstrlib.c
index ed88abdb4db2..2b5cd64b6ed9 100644
--- a/contrib/lua/src/lstrlib.c
+++ b/contrib/lua/src/lstrlib.c
@@ -152,8 +152,9 @@ static int str_rep (lua_State *L) {
   const char *s = luaL_checklstring(L, 1, &l);
   lua_Integer n = luaL_checkinteger(L, 2);
   const char *sep = luaL_optlstring(L, 3, "", &lsep);
-  if (n <= 0) lua_pushliteral(L, "");
-  else if (l + lsep < l || l + lsep > MAXSIZE / n)  /* may overflow? */
+  if (n <= 0)
+    lua_pushliteral(L, "");
+  else if (l_unlikely(l + lsep < l || l + lsep > MAXSIZE / n))
     return luaL_error(L, "resulting string too large");
   else {
     size_t totallen = (size_t)n * l + (size_t)(n - 1) * lsep;
@@ -181,7 +182,7 @@ static int str_byte (lua_State *L) {
   size_t pose = getendpos(L, 3, pi, l);
   int n, i;
   if (posi > pose) return 0;  /* empty interval; return no values */
-  if (pose - posi >= (size_t)INT_MAX)  /* arithmetic overflow? */
+  if (l_unlikely(pose - posi >= (size_t)INT_MAX))  /* arithmetic overflow? */
     return luaL_error(L, "string slice too long");
   n = (int)(pose -  posi) + 1;
   luaL_checkstack(L, n, "string slice too long");
@@ -235,7 +236,7 @@ static int str_dump (lua_State *L) {
   luaL_checktype(L, 1, LUA_TFUNCTION);
   lua_settop(L, 1);  /* ensure function is on the top of the stack */
   state.init = 0;
-  if (lua_dump(L, writer, &state, strip) != 0)
+  if (l_unlikely(lua_dump(L, writer, &state, strip) != 0))
     return luaL_error(L, "unable to dump given function");
   luaL_pushresult(&state.B);
   return 1;
@@ -275,7 +276,8 @@ static int tonum (lua_State *L, int arg) {
 
 static void trymt (lua_State *L, const char *mtname) {
   lua_settop(L, 2);  /* back to the original arguments */
-  if (lua_type(L, 2) == LUA_TSTRING || !luaL_getmetafield(L, 2, mtname))
+  if (l_unlikely(lua_type(L, 2) == LUA_TSTRING ||
+                 !luaL_getmetafield(L, 2, mtname)))
     luaL_error(L, "attempt to %s a '%s' with a '%s'", mtname + 2,
                   luaL_typename(L, -2), luaL_typename(L, -1));
   lua_insert(L, -3);  /* put metamethod before arguments */
@@ -383,7 +385,8 @@ static const char *match (MatchState *ms, const char *s, const char *p);
 
 static int check_capture (MatchState *ms, int l) {
   l -= '1';
-  if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
+  if (l_unlikely(l < 0 || l >= ms->level ||
+                 ms->capture[l].len == CAP_UNFINISHED))
     return luaL_error(ms->L, "invalid capture index %%%d", l + 1);
   return l;
 }
@@ -400,14 +403,14 @@ static int capture_to_close (MatchState *ms) {
 static const char *classend (MatchState *ms, const char *p) {
   switch (*p++) {
     case L_ESC: {
-      if (p == ms->p_end)
+      if (l_unlikely(p == ms->p_end))
         luaL_error(ms->L, "malformed pattern (ends with '%%')");
       return p+1;
     }
     case '[': {
       if (*p == '^') p++;
       do {  /* look for a ']' */
-        if (p == ms->p_end)
+        if (l_unlikely(p == ms->p_end))
           luaL_error(ms->L, "malformed pattern (missing ']')");
         if (*(p++) == L_ESC && p < ms->p_end)
           p++;  /* skip escapes (e.g. '%]') */
@@ -482,7 +485,7 @@ static int singlematch (MatchState *ms, const char *s, const char *p,
 
 static const char *matchbalance (MatchState *ms, const char *s,
                                    const char *p) {
-  if (p >= ms->p_end - 1)
+  if (l_unlikely(p >= ms->p_end - 1))
     luaL_error(ms->L, "malformed pattern (missing arguments to '%%b')");
   if (*s != *p) return NULL;
   else {
@@ -565,7 +568,7 @@ static const char *match_capture (MatchState *ms, const char *s, int l) {
 
 
 static const char *match (MatchState *ms, const char *s, const char *p) {
-  if (ms->matchdepth-- == 0)
+  if (l_unlikely(ms->matchdepth-- == 0))
     luaL_error(ms->L, "pattern too complex");
   init: /* using goto's to optimize tail recursion */
   if (p != ms->p_end) {  /* end of pattern? */
@@ -599,7 +602,7 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
           case 'f': {  /* frontier? */
             const char *ep; char previous;
             p += 2;
-            if (*p != '[')
+            if (l_unlikely(*p != '['))
               luaL_error(ms->L, "missing '[' after '%%f' in pattern");
             ep = classend(ms, p);  /* points to what is next */
             previous = (s == ms->src_init) ? '\0' : *(s - 1);
@@ -699,7 +702,7 @@ static const char *lmemfind (const char *s1, size_t l1,
 static size_t get_onecapture (MatchState *ms, int i, const char *s,
                               const char *e, const char **cap) {
   if (i >= ms->level) {
-    if (i != 0)
+    if (l_unlikely(i != 0))
       luaL_error(ms->L, "invalid capture index %%%d", i + 1);
     *cap = s;
     return e - s;
@@ -707,7 +710,7 @@ static size_t get_onecapture (MatchState *ms, int i, const char *s,
   else {
     ptrdiff_t capl = ms->capture[i].len;
     *cap = ms->capture[i].init;
-    if (capl == CAP_UNFINISHED)
+    if (l_unlikely(capl == CAP_UNFINISHED))
       luaL_error(ms->L, "unfinished capture");
     else if (capl == CAP_POSITION)
       lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1);
@@ -926,7 +929,7 @@ static int add_value (MatchState *ms, luaL_Buffer *b, const char *s,
     luaL_addlstring(b, s, e - s);  /* keep original text */
     return 0;  /* no changes */
   }
-  else if (!lua_isstring(L, -1))
+  else if (l_unlikely(!lua_isstring(L, -1)))
     return luaL_error(L, "invalid replacement value (a %s)",
                          luaL_typename(L, -1));
   else {
@@ -1058,7 +1061,7 @@ static int lua_number2strx (lua_State *L, char *buff, int sz,
     for (i = 0; i < n; i++)
       buff[i] = toupper(uchar(buff[i]));
   }
-  else if (fmt[SIZELENMOD] != 'a')
+  else if (l_unlikely(fmt[SIZELENMOD] != 'a'))
     return luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented");
   return n;
 }
@@ -1087,13 +1090,31 @@ static int lua_number2strx (lua_State *L, char *buff, int sz,
 
 
 /* valid flags in a format specification */
-#if !defined(L_FMTFLAGS)
-#define L_FMTFLAGS	"-+ #0"
+#if !defined(L_FMTFLAGSF)
+
+/* valid flags for a, A, e, E, f, F, g, and G conversions */
+#define L_FMTFLAGSF	"-+#0 "
+
+/* valid flags for o, x, and X conversions */
+#define L_FMTFLAGSX	"-#0"
+
+/* valid flags for d and i conversions */
+#define L_FMTFLAGSI	"-+0 "
+
+/* valid flags for u conversions */
+#define L_FMTFLAGSU	"-0"
+
+/* valid flags for c, p, and s conversions */
+#define L_FMTFLAGSC	"-"
+
 #endif
 
 
 /*
-** maximum size of each format specification (such as "%-099.99d")
+** Maximum size of each format specification (such as "%-099.99d"):
+** Initial '%', flags (up to 5), width (2), period, precision (2),
+** length modifier (8), conversion specifier, and final '\0', plus some
+** extra.
 */
 #define MAX_FORMAT	32
 
@@ -1121,7 +1142,7 @@ static void addquoted (luaL_Buffer *b, const char *s, size_t len) {
 }
 
 
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
+#ifndef LUA_AVOID_FLOAT
 /*
 ** Serialize a floating-point number in such a way that it can be
 ** scanned back by Lua. Use hexadecimal format for "common" numbers
@@ -1152,6 +1173,7 @@ static int quotefloat (lua_State *L, char *buff, lua_Number n) {
 }
 #endif
 
+
 static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
   switch (lua_type(L, arg)) {
     case LUA_TSTRING: {
@@ -1163,7 +1185,7 @@ static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
     case LUA_TNUMBER: {
       char *buff = luaL_prepbuffsize(b, MAX_ITEM);
       int nb;
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
+#ifndef LUA_AVOID_FLOAT
       if (!lua_isinteger(L, arg))  /* float? */
         nb = quotefloat(L, buff, lua_tonumber(L, arg));
       else {  /* integers */
@@ -1191,25 +1213,53 @@ static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
 }
 
 
-static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
-  const char *p = strfrmt;
-  while (*p != '\0' && strchr(L_FMTFLAGS, *p) != NULL) p++;  /* skip flags */
-  if ((size_t)(p - strfrmt) >= sizeof(L_FMTFLAGS)/sizeof(char))
-    luaL_error(L, "invalid format (repeated flags)");
-  if (isdigit(uchar(*p))) p++;  /* skip width */
-  if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
-  if (*p == '.') {
-    p++;
-    if (isdigit(uchar(*p))) p++;  /* skip precision */
-    if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
+static const char *get2digits (const char *s) {
+  if (isdigit(uchar(*s))) {
+    s++;
+    if (isdigit(uchar(*s))) s++;  /* (2 digits at most) */
+  }
+  return s;
+}
+
+
+/*
+** Check whether a conversion specification is valid. When called,
+** first character in 'form' must be '%' and last character must
+** be a valid conversion specifier. 'flags' are the accepted flags;
+** 'precision' signals whether to accept a precision.
+*/
+static void checkformat (lua_State *L, const char *form, const char *flags,
+                                       int precision) {
+  const char *spec = form + 1;  /* skip '%' */
+  spec += strspn(spec, flags);  /* skip flags */
+  if (*spec != '0') {  /* a width cannot start with '0' */
+    spec = get2digits(spec);  /* skip width */
+    if (*spec == '.' && precision) {
+      spec++;
+      spec = get2digits(spec);  /* skip precision */
+    }
   }
-  if (isdigit(uchar(*p)))
-    luaL_error(L, "invalid format (width or precision too long)");
+  if (!isalpha(uchar(*spec)))  /* did not go to the end? */
+    luaL_error(L, "invalid conversion specification: '%s'", form);
+}
+
+
+/*
+** Get a conversion specification and copy it to 'form'.
+** Return the address of its last character.
+*/
+static const char *getformat (lua_State *L, const char *strfrmt,
+                                            char *form) {
+  /* spans flags, width, and precision ('0' is included as a flag) */
+  size_t len = strspn(strfrmt, L_FMTFLAGSF "123456789.");
+  len++;  /* adds following character (should be the specifier) */
+  /* still needs space for '%', '\0', plus a length modifier */
+  if (len >= MAX_FORMAT - 10)
+    luaL_error(L, "invalid format (too long)");
   *(form++) = '%';
-  memcpy(form, strfrmt, ((p - strfrmt) + 1) * sizeof(char));
-  form += (p - strfrmt) + 1;
-  *form = '\0';
-  return p;
+  memcpy(form, strfrmt, len * sizeof(char));
+  *(form + len) = '\0';
+  return strfrmt + len - 1;
 }
 
 
@@ -1232,6 +1282,7 @@ static int str_format (lua_State *L) {
   size_t sfl;
   const char *strfrmt = luaL_checklstring(L, arg, &sfl);
   const char *strfrmt_end = strfrmt+sfl;
+  const char *flags;
   luaL_Buffer b;
   luaL_buffinit(L, &b);
   while (strfrmt < strfrmt_end) {
@@ -1241,30 +1292,40 @@ static int str_format (lua_State *L) {
       luaL_addchar(&b, *strfrmt++);  /* %% */
     else { /* format item */
       char form[MAX_FORMAT];  /* to store the format ('%...') */
-      int maxitem = MAX_ITEM;
-      char *buff = luaL_prepbuffsize(&b, maxitem);  /* to put formatted item */
-      int nb = 0;  /* number of bytes in added item */
+      int maxitem = MAX_ITEM;  /* maximum length for the result */
+      char *buff = luaL_prepbuffsize(&b, maxitem);  /* to put result */
+      int nb = 0;  /* number of bytes in result */
       if (++arg > top)
         return luaL_argerror(L, arg, "no value");
-      strfrmt = scanformat(L, strfrmt, form);
+      strfrmt = getformat(L, strfrmt, form);
       switch (*strfrmt++) {
         case 'c': {
+          checkformat(L, form, L_FMTFLAGSC, 0);
           nb = l_sprintf(buff, maxitem, form, (int)luaL_checkinteger(L, arg));
           break;
         }
         case 'd': case 'i':
-        case 'o': case 'u': case 'x': case 'X': {
+          flags = L_FMTFLAGSI;
+          goto intcase;
+        case 'u':
+          flags = L_FMTFLAGSU;
+          goto intcase;
+        case 'o': case 'x': case 'X':
+          flags = L_FMTFLAGSX;
+         intcase: {
           lua_Integer n = luaL_checkinteger(L, arg);
+          checkformat(L, form, flags, 1);
           addlenmod(form, LUA_INTEGER_FRMLEN);
           nb = l_sprintf(buff, maxitem, form, (LUAI_UACINT)n);
           break;
         }
         case 'a': case 'A':
+          checkformat(L, form, L_FMTFLAGSF, 1);
           addlenmod(form, LUA_NUMBER_FRMLEN);
           nb = lua_number2strx(L, buff, maxitem, form,
                                   luaL_checknumber(L, arg));
           break;
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
+#ifndef LUA_AVOID_FLOAT
         case 'f':
           maxitem = MAX_ITEMF;  /* extra space for '%f' */
           buff = luaL_prepbuffsize(&b, maxitem);
@@ -1272,12 +1333,14 @@ static int str_format (lua_State *L) {
 #endif
         case 'e': case 'E': case 'g': case 'G': {
           lua_Number n = luaL_checknumber(L, arg);
+          checkformat(L, form, L_FMTFLAGSF, 1);
           addlenmod(form, LUA_NUMBER_FRMLEN);
           nb = l_sprintf(buff, maxitem, form, (LUAI_UACNUMBER)n);
           break;
         }
         case 'p': {
           const void *p = lua_topointer(L, arg);
+          checkformat(L, form, L_FMTFLAGSC, 0);
           if (p == NULL) {  /* avoid calling 'printf' with argument NULL */
             p = "(null)";  /* result */
             form[strlen(form) - 1] = 's';  /* format it as a string */
@@ -1298,7 +1361,8 @@ static int str_format (lua_State *L) {
             luaL_addvalue(&b);  /* keep entire string */
           else {
             luaL_argcheck(L, l == strlen(s), arg, "string contains zeros");
-            if (!strchr(form, '.') && l >= 100) {
+            checkformat(L, form, L_FMTFLAGSC, 1);
+            if (strchr(form, '.') == NULL && l >= 100) {
               /* no precision and string is too long to be formatted */
               luaL_addvalue(&b);  /* keep entire string */
             }
@@ -1356,31 +1420,6 @@ static const union {
 } nativeendian = {1};
 
 
-/* dummy structure to get native alignment requirements */
-struct cD {
-  char c;
-  union {
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
-	  double d;
-#endif
-	  void *p; lua_Integer i; lua_Number n; } u;
-};
-
-#define MAXALIGN	(offsetof(struct cD, u))
-
-
-/*
-** Union for serializing floats
-*/
-typedef union Ftypes {
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
-  float f;
-  double d;
-#endif
-  lua_Number n;
-} Ftypes;
-
-
 /*
 ** information to pack/unpack stuff
 */
@@ -1397,7 +1436,11 @@ typedef struct Header {
 typedef enum KOption {
   Kint,		/* signed integers */
   Kuint,	/* unsigned integers */
-  Kfloat,	/* floating-point numbers */
+#ifndef LUA_AVOID_FLOAT
+  Kfloat,	/* single-precision floating-point numbers */
+  Kdouble,	/* double-precision floating-point numbers */
+#endif
+  Knumber,	/* Lua "native" floating-point numbers */
   Kchar,	/* fixed-length strings */
   Kstring,	/* strings with prefixed length */
   Kzstr,	/* zero-terminated strings */
@@ -1432,7 +1475,7 @@ static int getnum (const char **fmt, int df) {
 */
 static int getnumlimit (Header *h, const char **fmt, int df) {
   int sz = getnum(fmt, df);
-  if (sz > MAXINTSIZE || sz <= 0)
+  if (l_unlikely(sz > MAXINTSIZE || sz <= 0))
     return luaL_error(h->L, "integral size (%d) out of limits [1,%d]",
                             sz, MAXINTSIZE);
   return sz;
@@ -1453,6 +1496,8 @@ static void initheader (lua_State *L, Header *h) {
 ** Read and classify next option. 'size' is filled with option's size.
 */
 static KOption getoption (Header *h, const char **fmt, int *size) {
+  /* dummy structure to get native alignment requirements */
+  struct cD { char c; union { LUAI_MAXALIGN; } u; };
   int opt = *((*fmt)++);
   *size = 0;  /* default */
   switch (opt) {
@@ -1465,17 +1510,17 @@ static KOption getoption (Header *h, const char **fmt, int *size) {
     case 'j': *size = sizeof(lua_Integer); return Kint;
     case 'J': *size = sizeof(lua_Integer); return Kuint;
     case 'T': *size = sizeof(size_t); return Kuint;
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
+#ifndef LUA_AVOID_FLOAT
     case 'f': *size = sizeof(float); return Kfloat;
-    case 'd': *size = sizeof(double); return Kfloat;
+    case 'd': *size = sizeof(double); return Kdouble;
 #endif
-    case 'n': *size = sizeof(lua_Number); return Kfloat;
+    case 'n': *size = sizeof(lua_Number); return Knumber;
     case 'i': *size = getnumlimit(h, fmt, sizeof(int)); return Kint;
     case 'I': *size = getnumlimit(h, fmt, sizeof(int)); return Kuint;
     case 's': *size = getnumlimit(h, fmt, sizeof(size_t)); return Kstring;
     case 'c':
       *size = getnum(fmt, -1);
-      if (*size == -1)
+      if (l_unlikely(*size == -1))
         luaL_error(h->L, "missing size for format option 'c'");
       return Kchar;
     case 'z': return Kzstr;
@@ -1485,7 +1530,11 @@ static KOption getoption (Header *h, const char **fmt, int *size) {
     case '<': h->islittle = 1; break;
     case '>': h->islittle = 0; break;
     case '=': h->islittle = nativeendian.little; break;
-    case '!': h->maxalign = getnumlimit(h, fmt, MAXALIGN); break;
+    case '!': {
+      const int maxalign = offsetof(struct cD, u);
+      h->maxalign = getnumlimit(h, fmt, maxalign);
+      break;
+    }
     default: luaL_error(h->L, "invalid format option '%c'", opt);
   }
   return Knop;
@@ -1514,7 +1563,7 @@ static KOption getdetails (Header *h, size_t totalsize,
   else {
     if (align > h->maxalign)  /* enforce maximum alignment */
       align = h->maxalign;
-    if ((align & (align - 1)) != 0)  /* is 'align' not a power of 2? */
+    if (l_unlikely((align & (align - 1)) != 0))  /* not a power of 2? */
       luaL_argerror(h->L, 1, "format asks for alignment not power of 2");
     *ntoalign = (align - (int)(totalsize & (align - 1))) & (align - 1);
   }
@@ -1595,22 +1644,34 @@ static int str_pack (lua_State *L) {
         packint(&b, (lua_Unsigned)n, h.islittle, size, 0);
         break;
       }
-      case Kfloat: {  /* floating-point options */
-        Ftypes u;
-        char *buff = luaL_prepbuffsize(&b, size);
-        lua_Number n = luaL_checknumber(L, arg);  /* get argument */
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
-        if (size == sizeof(u.f)) u.f = (float)n;  /* copy it into 'u' */
-        else if (size == sizeof(u.d)) u.d = (double)n;
-        else u.n = n;
-#else
-	u.n = n;
+#ifndef LUA_AVOID_FLOAT
+      case Kfloat: {  /* C float */
+        float f = (float)luaL_checknumber(L, arg);  /* get argument */
+        char *buff = luaL_prepbuffsize(&b, sizeof(f));
+        /* move 'f' to final result, correcting endianness if needed */
+        copywithendian(buff, (char *)&f, sizeof(f), h.islittle);
+        luaL_addsize(&b, size);
+        break;
+      }
 #endif
-        /* move 'u' to final result, correcting endianness if needed */
-        copywithendian(buff, (char *)&u, size, h.islittle);
+      case Knumber: {  /* Lua float */
+        lua_Number f = luaL_checknumber(L, arg);  /* get argument */
+        char *buff = luaL_prepbuffsize(&b, sizeof(f));
+        /* move 'f' to final result, correcting endianness if needed */
+        copywithendian(buff, (char *)&f, sizeof(f), h.islittle);
+        luaL_addsize(&b, size);
+        break;
+      }
+#ifndef LUA_AVOID_FLOAT
+      case Kdouble: {  /* C double */
+        double f = (double)luaL_checknumber(L, arg);  /* get argument */
+        char *buff = luaL_prepbuffsize(&b, sizeof(f));
+        /* move 'f' to final result, correcting endianness if needed */
+        copywithendian(buff, (char *)&f, sizeof(f), h.islittle);
         luaL_addsize(&b, size);
         break;
       }
+#endif
       case Kchar: {  /* fixed-size string */
         size_t len;
         const char *s = luaL_checklstring(L, arg, &len);
@@ -1698,7 +1759,7 @@ static lua_Integer unpackint (lua_State *L, const char *str,
   else if (size > SZINT) {  /* must check unread bytes */
     int mask = (!issigned || (lua_Integer)res >= 0) ? 0 : MC;
     for (i = limit; i < size; i++) {
-      if ((unsigned char)str[islittle ? i : size - 1 - i] != mask)
+      if (l_unlikely((unsigned char)str[islittle ? i : size - 1 - i] != mask))
         luaL_error(L, "%d-byte integer does not fit into Lua Integer", size);
     }
   }
@@ -1732,20 +1793,28 @@ static int str_unpack (lua_State *L) {
         lua_pushinteger(L, res);
         break;
       }
+#ifndef LUA_AVOID_FLOAT
       case Kfloat: {
-        Ftypes u;
-        lua_Number num;
-        copywithendian((char *)&u, data + pos, size, h.islittle);
-#if LUA_FLOAT_TYPE != LUA_FLOAT_INT64
-        if (size == sizeof(u.f)) num = (lua_Number)u.f;
-        else if (size == sizeof(u.d)) num = (lua_Number)u.d;
-        else num = u.n;
-#else
-	num = u.n;
+        float f;
+        copywithendian((char *)&f, data + pos, sizeof(f), h.islittle);
+        lua_pushnumber(L, (lua_Number)f);
+        break;
+      }
 #endif
-        lua_pushnumber(L, num);
+      case Knumber: {
+        lua_Number f;
+        copywithendian((char *)&f, data + pos, sizeof(f), h.islittle);
+        lua_pushnumber(L, f);
         break;
       }
+#ifndef LUA_AVOID_FLOAT
+      case Kdouble: {
+        double f;
+        copywithendian((char *)&f, data + pos, sizeof(f), h.islittle);
+        lua_pushnumber(L, (lua_Number)f);
+        break;
+      }
+#endif
       case Kchar: {
         lua_pushlstring(L, data + pos, size);
         break;
diff --git a/contrib/lua/src/ltable.c b/contrib/lua/src/ltable.c
index 7e7cbed97cbf..1b1cd2415b60 100644
--- a/contrib/lua/src/ltable.c
+++ b/contrib/lua/src/ltable.c
@@ -68,20 +68,23 @@
 #define MAXHSIZE	luaM_limitN(1u << MAXHBITS, Node)
 
 
+/*
+** When the original hash value is good, hashing by a power of 2
+** avoids the cost of '%'.
+*/
 #define hashpow2(t,n)		(gnode(t, lmod((n), sizenode(t))))
 
-#define hashstr(t,str)		hashpow2(t, (str)->hash)
-#define hashboolean(t,p)	hashpow2(t, p)
-#define hashint(t,i)		hashpow2(t, i)
-
-
 /*
-** for some types, it is better to avoid modulus by power of 2, as
-** they tend to have many 2 factors.
+** for other types, it is better to avoid modulo by power of 2, as
+** they can have many 2 factors.
 */
 #define hashmod(t,n)	(gnode(t, ((n) % ((sizenode(t)-1)|1))))
 
 
+#define hashstr(t,str)		hashpow2(t, (str)->hash)
+#define hashboolean(t,p)	hashpow2(t, p)
+
+
 #define hashpointer(t,p)	hashmod(t, point2uint(p))
 
 
@@ -96,6 +99,20 @@ static const Node dummynode_ = {
 static const TValue absentkey = {ABSTKEYCONSTANT};
 
 
+/*
+** Hash for integers. To allow a good hash, use the remainder operator
+** ('%'). If integer fits as a non-negative int, compute an int
+** remainder, which is faster. Otherwise, use an unsigned-integer
+** remainder, which uses all bits and ensures a non-negative result.
+*/
+static Node *hashint (const Table *t, lua_Integer i) {
+  lua_Unsigned ui = l_castS2U(i);
+  if (ui <= (unsigned int)INT_MAX)
+    return hashmod(t, cast_int(ui));
+  else
+    return hashmod(t, ui);
+}
+
 
 /*
 ** Hash for floating-point numbers.
@@ -129,39 +146,50 @@ static int l_hashfloat (lua_Number n) {
 
 /*
 ** returns the 'main' position of an element in a table (that is,
-** the index of its hash value). The key comes broken (tag in 'ktt'
-** and value in 'vkl') so that we can call it on keys inserted into
-** nodes.
+** the index of its hash value).
 */
-static Node *mainposition (const Table *t, int ktt, const Value *kvl) {
-  switch (withvariant(ktt)) {
-    case LUA_VNUMINT:
-      return hashint(t, ivalueraw(*kvl));
-    case LUA_VNUMFLT:
-      return hashmod(t, l_hashfloat(fltvalueraw(*kvl)));
-    case LUA_VSHRSTR:
-      return hashstr(t, tsvalueraw(*kvl));
-    case LUA_VLNGSTR:
-      return hashpow2(t, luaS_hashlongstr(tsvalueraw(*kvl)));
+static Node *mainpositionTV (const Table *t, const TValue *key) {
+  switch (ttypetag(key)) {
+    case LUA_VNUMINT: {
+      lua_Integer i = ivalue(key);
+      return hashint(t, i);
+    }
+    case LUA_VNUMFLT: {
+      lua_Number n = fltvalue(key);
+      return hashmod(t, l_hashfloat(n));
+    }
+    case LUA_VSHRSTR: {
+      TString *ts = tsvalue(key);
+      return hashstr(t, ts);
+    }
+    case LUA_VLNGSTR: {
+      TString *ts = tsvalue(key);
+      return hashpow2(t, luaS_hashlongstr(ts));
+    }
     case LUA_VFALSE:
       return hashboolean(t, 0);
     case LUA_VTRUE:
       return hashboolean(t, 1);
-    case LUA_VLIGHTUSERDATA:
-      return hashpointer(t, pvalueraw(*kvl));
-    case LUA_VLCF:
-      return hashpointer(t, fvalueraw(*kvl));
-    default:
-      return hashpointer(t, gcvalueraw(*kvl));
+    case LUA_VLIGHTUSERDATA: {
+      void *p = pvalue(key);
+      return hashpointer(t, p);
+    }
+    case LUA_VLCF: {
+      lua_CFunction f = fvalue(key);
+      return hashpointer(t, f);
+    }
+    default: {
+      GCObject *o = gcvalue(key);
+      return hashpointer(t, o);
+    }
   }
 }
 
 
-/*
-** Returns the main position of an element given as a 'TValue'
-*/
-static Node *mainpositionTV (const Table *t, const TValue *key) {
-  return mainposition(t, rawtt(key), valraw(key));
+l_sinline Node *mainpositionfromnode (const Table *t, Node *nd) {
+  TValue key;
+  getnodekey(cast(lua_State *, NULL), &key, nd);
+  return mainpositionTV(t, &key);
 }
 
 
@@ -307,7 +335,7 @@ static unsigned int findindex (lua_State *L, Table *t, TValue *key,
     return i;  /* yes; that's the index */
   else {
     const TValue *n = getgeneric(t, key, 1);
-    if (unlikely(isabstkey(n)))
+    if (l_unlikely(isabstkey(n)))
       luaG_runerror(L, "invalid key to 'next'");  /* key not found */
     i = cast_int(nodefromval(n) - gnode(t, 0));  /* key index in hash table */
     /* hash elements are numbered after array ones */
@@ -485,7 +513,7 @@ static void reinsert (lua_State *L, Table *ot, Table *t) {
          already present in the table */
       TValue k;
       getnodekey(L, &k, old);
-      setobjt2t(L, luaH_set(L, t, &k), gval(old));
+      luaH_set(L, t, &k, gval(old));
     }
   }
 }
@@ -541,7 +569,7 @@ void luaH_resize (lua_State *L, Table *t, unsigned int newasize,
   }
   /* allocate new array */
   newarray = luaM_reallocvector(L, t->array, oldasize, newasize, TValue);
-  if (unlikely(newarray == NULL && newasize > 0)) {  /* allocation failed? */
+  if (l_unlikely(newarray == NULL && newasize > 0)) {  /* allocation failed? */
     freehash(L, &newt);  /* release new hash part */
     luaM_error(L);  /* raise error (with array unchanged) */
   }
@@ -632,10 +660,10 @@ static Node *getfreepos (Table *t) {
 ** put new key in its main position; otherwise (colliding node is in its main
 ** position), new key goes to an empty position.
 */
-TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
+void luaH_newkey (lua_State *L, Table *t, const TValue *key, TValue *value) {
   Node *mp;
   TValue aux;
-  if (unlikely(ttisnil(key)))
+  if (l_unlikely(ttisnil(key)))
     luaG_runerror(L, "table index is nil");
   else if (ttisfloat(key)) {
     lua_Number f = fltvalue(key);
@@ -644,9 +672,11 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
       setivalue(&aux, k);
       key = &aux;  /* insert it as an integer */
     }
-    else if (unlikely(luai_numisnan(f)))
+    else if (l_unlikely(luai_numisnan(f)))
       luaG_runerror(L, "table index is NaN");
   }
+  if (ttisnil(value))
+    return;  /* do not insert nil values */
   mp = mainpositionTV(t, key);
   if (!isempty(gval(mp)) || isdummy(t)) {  /* main position is taken? */
     Node *othern;
@@ -654,10 +684,11 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
     if (f == NULL) {  /* cannot find a free place? */
       rehash(L, t, key);  /* grow table */
       /* whatever called 'newkey' takes care of TM cache */
-      return luaH_set(L, t, key);  /* insert key into grown table */
+      luaH_set(L, t, key, value);  /* insert key into grown table */
+      return;
     }
     lua_assert(!isdummy(t));
-    othern = mainposition(t, keytt(mp), &keyval(mp));
+    othern = mainpositionfromnode(t, mp);
     if (othern != mp) {  /* is colliding node out of its main position? */
       /* yes; move colliding node into free position */
       while (othern + gnext(othern) != mp)  /* find previous */
@@ -682,7 +713,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
   setnodekey(L, mp, key);
   luaC_barrierback(L, obj2gco(t), key);
   lua_assert(isempty(gval(mp)));
-  return gval(mp);
+  setobj2t(L, gval(mp), value);
 }
 
 
@@ -770,28 +801,39 @@ const TValue *luaH_get (Table *t, const TValue *key) {
 
 
 /*
+** Finish a raw "set table" operation, where 'slot' is where the value
+** should have been (the result of a previous "get table").
+** Beware: when using this function you probably need to check a GC
+** barrier and invalidate the TM cache.
+*/
+void luaH_finishset (lua_State *L, Table *t, const TValue *key,
+                                   const TValue *slot, TValue *value) {
+  if (isabstkey(slot))
+    luaH_newkey(L, t, key, value);
+  else
+    setobj2t(L, cast(TValue *, slot), value);
+}
+
+
+/*
 ** beware: when using this function you probably need to check a GC
 ** barrier and invalidate the TM cache.
 */
-TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
-  const TValue *p = luaH_get(t, key);
-  if (!isabstkey(p))
-    return cast(TValue *, p);
-  else return luaH_newkey(L, t, key);
+void luaH_set (lua_State *L, Table *t, const TValue *key, TValue *value) {
+  const TValue *slot = luaH_get(t, key);
+  luaH_finishset(L, t, key, slot, value);
 }
 
 
 void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
   const TValue *p = luaH_getint(t, key);
-  TValue *cell;
-  if (!isabstkey(p))
-    cell = cast(TValue *, p);
-  else {
+  if (isabstkey(p)) {
     TValue k;
     setivalue(&k, key);
-    cell = luaH_newkey(L, t, &k);
+    luaH_newkey(L, t, &k, value);
   }
-  setobj2t(L, cell, value);
+  else
+    setobj2t(L, cast(TValue *, p), value);
 }
 
 
diff --git a/contrib/lua/src/ltable.h b/contrib/lua/src/ltable.h
index c0060f4b6e70..7bbbcb213f8b 100644
--- a/contrib/lua/src/ltable.h
+++ b/contrib/lua/src/ltable.h
@@ -41,8 +41,12 @@ LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key,
 LUAI_FUNC const TValue *luaH_getshortstr (Table *t, TString *key);
 LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key);
 LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key);
-LUAI_FUNC TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key);
-LUAI_FUNC TValue *luaH_set (lua_State *L, Table *t, const TValue *key);
+LUAI_FUNC void luaH_newkey (lua_State *L, Table *t, const TValue *key,
+                                                    TValue *value);
+LUAI_FUNC void luaH_set (lua_State *L, Table *t, const TValue *key,
+                                                 TValue *value);
+LUAI_FUNC void luaH_finishset (lua_State *L, Table *t, const TValue *key,
+                                       const TValue *slot, TValue *value);
 LUAI_FUNC Table *luaH_new (lua_State *L);
 LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
                                                     unsigned int nhsize);
diff --git a/contrib/lua/src/ltablib.c b/contrib/lua/src/ltablib.c
index d344a47e9ad2..868d78fd83ec 100644
--- a/contrib/lua/src/ltablib.c
+++ b/contrib/lua/src/ltablib.c
@@ -59,8 +59,9 @@ static void checktab (lua_State *L, int arg, int what) {
 
 
 static int tinsert (lua_State *L) {
-  lua_Integer e = aux_getn(L, 1, TAB_RW) + 1;  /* first empty element */
   lua_Integer pos;  /* where to insert new element */
+  lua_Integer e = aux_getn(L, 1, TAB_RW);
+  e = luaL_intop(+, e, 1);  /* first empty element */
   switch (lua_gettop(L)) {
     case 2: {  /* called with only 2 arguments */
       pos = e;  /* insert new element at the end */
@@ -145,9 +146,9 @@ static int tmove (lua_State *L) {
 
 static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
   lua_geti(L, 1, i);
-  if (!lua_isstring(L, -1))
-    luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
-                  luaL_typename(L, -1), i);
+  if (l_unlikely(!lua_isstring(L, -1)))
+    luaL_error(L, "invalid value (%s) at index %I in table for 'concat'",
+                  luaL_typename(L, -1), (LUAI_UACINT)i);
   luaL_addvalue(b);
 }
 
@@ -196,7 +197,8 @@ static int tunpack (lua_State *L) {
   lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
   if (i > e) return 0;  /* empty range */
   n = (lua_Unsigned)e - i;  /* number of elements minus 1 (avoid overflows) */
-  if (n >= (unsigned int)INT_MAX  || !lua_checkstack(L, (int)(++n)))
+  if (l_unlikely(n >= (unsigned int)INT_MAX  ||
+                 !lua_checkstack(L, (int)(++n))))
     return luaL_error(L, "too many results to unpack");
   for (; i < e; i++) {  /* push arg[i..e - 1] (to avoid overflows) */
     lua_geti(L, 1, i);
@@ -300,14 +302,14 @@ static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
   for (;;) {
     /* next loop: repeat ++i while a[i] < P */
     while ((void)lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
-      if (i == up - 1)  /* a[i] < P  but a[up - 1] == P  ?? */
+      if (l_unlikely(i == up - 1))  /* a[i] < P  but a[up - 1] == P  ?? */
         luaL_error(L, "invalid order function for sorting");
       lua_pop(L, 1);  /* remove a[i] */
     }
     /* after the loop, a[i] >= P and a[lo .. i - 1] < P */
     /* next loop: repeat --j while P < a[j] */
     while ((void)lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
-      if (j < i)  /* j < i  but  a[j] > P ?? */
+      if (l_unlikely(j < i))  /* j < i  but  a[j] > P ?? */
         luaL_error(L, "invalid order function for sorting");
       lua_pop(L, 1);  /* remove a[j] */
     }
diff --git a/contrib/lua/src/ltm.c b/contrib/lua/src/ltm.c
index 4770f96bb612..b657b783a801 100644
--- a/contrib/lua/src/ltm.c
+++ b/contrib/lua/src/ltm.c
@@ -147,7 +147,7 @@ static int callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
 
 void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
                     StkId res, TMS event) {
-  if (!callbinTM(L, p1, p2, res, event)) {
+  if (l_unlikely(!callbinTM(L, p1, p2, res, event))) {
     switch (event) {
       case TM_BAND: case TM_BOR: case TM_BXOR:
       case TM_SHL: case TM_SHR: case TM_BNOT: {
@@ -166,7 +166,8 @@ void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
 
 void luaT_tryconcatTM (lua_State *L) {
   StkId top = L->top;
-  if (!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2, TM_CONCAT))
+  if (l_unlikely(!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2,
+                               TM_CONCAT)))
     luaG_concaterror(L, s2v(top - 2), s2v(top - 1));
 }
 
diff --git a/contrib/lua/src/lua.c b/contrib/lua/src/lua.c
index b5b884b6d016..0f1900444499 100644
--- a/contrib/lua/src/lua.c
+++ b/contrib/lua/src/lua.c
@@ -37,6 +37,26 @@ static lua_State *globalL = NULL;
 static const char *progname = LUA_PROGNAME;
 
 
+#if defined(LUA_USE_POSIX)   /* { */
+
+/*
+** Use 'sigaction' when available.
+*/
+static void setsignal (int sig, void (*handler)(int)) {
+  struct sigaction sa;
+  sa.sa_handler = handler;
+  sa.sa_flags = 0;
+  sigemptyset(&sa.sa_mask);  /* do not mask any signal */
+  sigaction(sig, &sa, NULL);
+}
+
+#else           /* }{ */
+
+#define setsignal            signal
+
+#endif                               /* } */
+
+
 /*
 ** Hook set by signal function to stop the interpreter.
 */
@@ -55,7 +75,7 @@ static void lstop (lua_State *L, lua_Debug *ar) {
 */
 static void laction (int i) {
   int flag = LUA_MASKCALL | LUA_MASKRET | LUA_MASKLINE | LUA_MASKCOUNT;
-  signal(i, SIG_DFL); /* if another SIGINT happens, terminate process */
+  setsignal(i, SIG_DFL); /* if another SIGINT happens, terminate process */
   lua_sethook(globalL, lstop, flag, 1);
 }
 
@@ -69,14 +89,15 @@ static void print_usage (const char *badoption) {
   lua_writestringerror(
   "usage: %s [options] [script [args]]\n"
   "Available options are:\n"
-  "  -e stat  execute string 'stat'\n"
-  "  -i       enter interactive mode after executing 'script'\n"
-  "  -l name  require library 'name' into global 'name'\n"
-  "  -v       show version information\n"
-  "  -E       ignore environment variables\n"
-  "  -W       turn warnings on\n"
-  "  --       stop handling options\n"
-  "  -        stop handling options and execute stdin\n"
+  "  -e stat   execute string 'stat'\n"
+  "  -i        enter interactive mode after executing 'script'\n"
+  "  -l mod    require library 'mod' into global 'mod'\n"
+  "  -l g=mod  require library 'mod' into global 'g'\n"
+  "  -v        show version information\n"
+  "  -E        ignore environment variables\n"
+  "  -W        turn warnings on\n"
+  "  --        stop handling options\n"
+  "  -         stop handling options and execute stdin\n"
   ,
   progname);
 }
@@ -135,9 +156,9 @@ static int docall (lua_State *L, int narg, int nres) {
   lua_pushcfunction(L, msghandler);  /* push message handler */
   lua_insert(L, base);  /* put it under function and args */
   globalL = L;  /* to be available to 'laction' */
-  signal(SIGINT, laction);  /* set C-signal handler */
+  setsignal(SIGINT, laction);  /* set C-signal handler */
   status = lua_pcall(L, narg, nres, base);
-  signal(SIGINT, SIG_DFL); /* reset C-signal handler */
+  setsignal(SIGINT, SIG_DFL); /* reset C-signal handler */
   lua_remove(L, base);  /* remove message handler from the stack */
   return status;
 }
@@ -187,16 +208,22 @@ static int dostring (lua_State *L, const char *s, const char *name) {
 
 
 /*
-** Calls 'require(name)' and stores the result in a global variable
-** with the given name.
+** Receives 'globname[=modname]' and runs 'globname = require(modname)'.
 */
-static int dolibrary (lua_State *L, const char *name) {
+static int dolibrary (lua_State *L, char *globname) {
   int status;
+  char *modname = strchr(globname, '=');
+  if (modname == NULL)  /* no explicit name? */
+    modname = globname;  /* module name is equal to global name */
+  else {
+    *modname = '\0';  /* global name ends here */
+    modname++;  /* module name starts after the '=' */
+  }
   lua_getglobal(L, "require");
-  lua_pushstring(L, name);
-  status = docall(L, 1, 1);  /* call 'require(name)' */
+  lua_pushstring(L, modname);
+  status = docall(L, 1, 1);  /* call 'require(modname)' */
   if (status == LUA_OK)
-    lua_setglobal(L, name);  /* global[name] = require return */
+    lua_setglobal(L, globname);  /* globname = require(modname) */
   return report(L, status);
 }
 
@@ -307,7 +334,7 @@ static int runargs (lua_State *L, char **argv, int n) {
     switch (option) {
       case 'e':  case 'l': {
         int status;
-        const char *extra = argv[i] + 2;  /* both options need an argument */
+        char *extra = argv[i] + 2;  /* both options need an argument */
         if (*extra == '\0') extra = argv[++i];
         lua_assert(extra != NULL);
         status = (option == 'e')
diff --git a/contrib/lua/src/lua.h b/contrib/lua/src/lua.h
index c9d64d7f2124..e6618392cc7e 100644
--- a/contrib/lua/src/lua.h
+++ b/contrib/lua/src/lua.h
@@ -18,14 +18,14 @@
 
 #define LUA_VERSION_MAJOR	"5"
 #define LUA_VERSION_MINOR	"4"
-#define LUA_VERSION_RELEASE	"2"
+#define LUA_VERSION_RELEASE	"4"
 
 #define LUA_VERSION_NUM			504
-#define LUA_VERSION_RELEASE_NUM		(LUA_VERSION_NUM * 100 + 0)
+#define LUA_VERSION_RELEASE_NUM		(LUA_VERSION_NUM * 100 + 4)
 
 #define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
 #define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
-#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2020 Lua.org, PUC-Rio"
+#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2022 Lua.org, PUC-Rio"
 #define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
 
 
@@ -347,7 +347,8 @@ LUA_API size_t   (lua_stringtonumber) (lua_State *L, const char *s);
 LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);
 LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
-LUA_API void  (lua_toclose) (lua_State *L, int idx);
+LUA_API void (lua_toclose) (lua_State *L, int idx);
+LUA_API void (lua_closeslot) (lua_State *L, int idx);
 
 
 /*
@@ -491,7 +492,7 @@ struct lua_Debug {
 
 
 /******************************************************************************
-* Copyright (C) 1994-2020 Lua.org, PUC-Rio.
+* Copyright (C) 1994-2022 Lua.org, PUC-Rio.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
diff --git a/contrib/lua/src/luac.c b/contrib/lua/src/luac.c
index 56ddc41483f4..f6db9cf656bb 100644
--- a/contrib/lua/src/luac.c
+++ b/contrib/lua/src/luac.c
@@ -155,6 +155,7 @@ static const Proto* combine(lua_State* L, int n)
    f->p[i]=toproto(L,i-n-1);
    if (f->p[i]->sizeupvalues>0) f->p[i]->upvalues[0].instack=0;
   }
+  luaM_freearray(L,f->lineinfo,f->sizelineinfo);
   f->sizelineinfo=0;
   return f;
  }
@@ -600,11 +601,11 @@ static void PrintCode(const Proto* f)
 	if (c==0) printf("all out"); else printf("%d out",c-1);
 	break;
    case OP_TAILCALL:
-	printf("%d %d %d",a,b,c);
+	printf("%d %d %d%s",a,b,c,ISK);
 	printf(COMMENT "%d in",b-1);
 	break;
    case OP_RETURN:
-	printf("%d %d %d",a,b,c);
+	printf("%d %d %d%s",a,b,c,ISK);
 	printf(COMMENT);
 	if (b==0) printf("all out"); else printf("%d out",b-1);
 	break;
@@ -619,7 +620,7 @@ static void PrintCode(const Proto* f)
 	break;
    case OP_FORPREP:
 	printf("%d %d",a,bx);
-	printf(COMMENT "to %d",pc+bx+2);
+	printf(COMMENT "exit to %d",pc+bx+3);
 	break;
    case OP_TFORPREP:
 	printf("%d %d",a,bx);
diff --git a/contrib/lua/src/luaconf.h b/contrib/lua/src/luaconf.h
new file mode 100644
index 000000000000..eab6318aaaef
--- /dev/null
+++ b/contrib/lua/src/luaconf.h
@@ -0,0 +1,786 @@
+/*
+** $Id: luaconf.h $
+** Configuration file for Lua
+** See Copyright Notice in lua.h
+*/
+
+
+#ifndef luaconf_h
+#define luaconf_h
+
+#include <limits.h>
+#include <stddef.h>
+
+
+/*
+** ===================================================================
+** General Configuration File for Lua
+**
+** Some definitions here can be changed externally, through the compiler
+** (e.g., with '-D' options): They are commented out or protected
+** by '#if !defined' guards. However, several other definitions
+** should be changed directly here, either because they affect the
+** Lua ABI (by making the changes here, you ensure that all software
+** connected to Lua, such as C libraries, will be compiled with the same
+** configuration); or because they are seldom changed.
+**
+** Search for "@@" to find all configurable definitions.
+** ===================================================================
+*/
+
+
+/*
+** {====================================================================
+** System Configuration: macros to adapt (if needed) Lua to some
+** particular platform, for instance restricting it to C89.
+** =====================================================================
+*/
+
+/*
+@@ LUA_USE_C89 controls the use of non-ISO-C89 features.
+** Define it if you want Lua to avoid the use of a few C99 features
+** or Windows-specific features on Windows.
+*/
+/* #define LUA_USE_C89 */
+
+
+/*
+** By default, Lua on Windows use (some) specific Windows features
+*/
+#if !defined(LUA_USE_C89) && defined(_WIN32) && !defined(_WIN32_WCE)
+#define LUA_USE_WINDOWS  /* enable goodies for regular Windows */
+#endif
+
+
+#if defined(LUA_USE_WINDOWS)
+#define LUA_DL_DLL	/* enable support for DLL */
+#define LUA_USE_C89	/* broadly, Windows is C89 */
+#endif
+
+
+#if defined(LUA_USE_LINUX)
+#define LUA_USE_POSIX
+#define LUA_USE_DLOPEN		/* needs an extra library: -ldl */
+#endif
+
+
+#if defined(LUA_USE_MACOSX)
+#define LUA_USE_POSIX
+#define LUA_USE_DLOPEN		/* MacOS does not need -ldl */
+#endif
+
+
+/*
+@@ LUAI_IS32INT is true iff 'int' has (at least) 32 bits.
+*/
+#define LUAI_IS32INT	((UINT_MAX >> 30) >= 3)
+
+/* }================================================================== */
+
+
+
+/*
+** {==================================================================
+** Configuration for Number types. These options should not be
+** set externally, because any other code connected to Lua must
+** use the same configuration.
+** ===================================================================
+*/
+
+/*
+@@ LUA_INT_TYPE defines the type for Lua integers.
+@@ LUA_FLOAT_TYPE defines the type for Lua floats.
+** Lua should work fine with any mix of these options supported
+** by your C compiler. The usual configurations are 64-bit integers
+** and 'double' (the default), 32-bit integers and 'float' (for
+** restricted platforms), and 'long'/'double' (for C compilers not
+** compliant with C99, which may not have support for 'long long').
+*/
+
+/* predefined options for LUA_INT_TYPE */
+#define LUA_INT_INT		1
+#define LUA_INT_LONG		2
+#define LUA_INT_LONGLONG	3
+
+/* predefined options for LUA_FLOAT_TYPE */
+#define LUA_FLOAT_FLOAT		1
+#define LUA_FLOAT_DOUBLE	2
+#define LUA_FLOAT_LONGDOUBLE	3
+
+
+/* Default configuration ('long long' and 'double', for 64-bit Lua) */
+#define LUA_INT_DEFAULT		LUA_INT_LONGLONG
+#define LUA_FLOAT_DEFAULT	LUA_FLOAT_DOUBLE
+
+
+/*
+@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats.
+*/
+#define LUA_32BITS	0
+
+
+/*
+@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
+** C89 ('long' and 'double'); Windows always has '__int64', so it does
+** not need to use this case.
+*/
+#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
+#define LUA_C89_NUMBERS		1
+#else
+#define LUA_C89_NUMBERS		0
+#endif
+
+
+#if LUA_32BITS		/* { */
+/*
+** 32-bit integers and 'float'
+*/
+#if LUAI_IS32INT  /* use 'int' if big enough */
+#define LUA_INT_TYPE	LUA_INT_INT
+#else  /* otherwise use 'long' */
+#define LUA_INT_TYPE	LUA_INT_LONG
+#endif
+#define LUA_FLOAT_TYPE	LUA_FLOAT_FLOAT
+
+#elif LUA_C89_NUMBERS	/* }{ */
+/*
+** largest types available for C89 ('long' and 'double')
+*/
+#define LUA_INT_TYPE	LUA_INT_LONG
+#define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
+
+#else		/* }{ */
+/* use defaults */
+
+#define LUA_INT_TYPE	LUA_INT_DEFAULT
+#define LUA_FLOAT_TYPE	LUA_FLOAT_DEFAULT
+
+#endif				/* } */
+
+
+/* }================================================================== */
+
+
+
+/*
+** {==================================================================
+** Configuration for Paths.
+** ===================================================================
+*/
+
+/*
+** LUA_PATH_SEP is the character that separates templates in a path.
+** LUA_PATH_MARK is the string that marks the substitution points in a
+** template.
+** LUA_EXEC_DIR in a Windows path is replaced by the executable's
+** directory.
+*/
+#define LUA_PATH_SEP            ";"
+#define LUA_PATH_MARK           "?"
+#define LUA_EXEC_DIR            "!"
+
+
+/*
+@@ LUA_PATH_DEFAULT is the default path that Lua uses to look for
+** Lua libraries.
+@@ LUA_CPATH_DEFAULT is the default path that Lua uses to look for
+** C libraries.
+** CHANGE them if your machine has a non-conventional directory
+** hierarchy or if you want to install your libraries in
+** non-conventional directories.
+*/
+
+#define LUA_VDIR	LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
+#if defined(_WIN32)	/* { */
+/*
+** In Windows, any exclamation mark ('!') in the path is replaced by the
+** path of the directory of the executable file of the current process.
+*/
+#define LUA_LDIR	"!\\lua\\"
+#define LUA_CDIR	"!\\"
+#define LUA_SHRDIR	"!\\..\\share\\lua\\" LUA_VDIR "\\"
+
+#if !defined(LUA_PATH_DEFAULT)
+#define LUA_PATH_DEFAULT  \
+		LUA_LDIR"?.lua;"  LUA_LDIR"?\\init.lua;" \
+		LUA_CDIR"?.lua;"  LUA_CDIR"?\\init.lua;" \
+		LUA_SHRDIR"?.lua;" LUA_SHRDIR"?\\init.lua;" \
+		".\\?.lua;" ".\\?\\init.lua"
+#endif
+
+#if !defined(LUA_CPATH_DEFAULT)
+#define LUA_CPATH_DEFAULT \
+		LUA_CDIR"?.dll;" \
+		LUA_CDIR"..\\lib\\lua\\" LUA_VDIR "\\?.dll;" \
+		LUA_CDIR"loadall.dll;" ".\\?.dll"
+#endif
+
+#else			/* }{ */
+
+#define LUA_ROOT	"/usr/local/"
+#define LUA_LDIR	LUA_ROOT "share/lua/" LUA_VDIR "/"
+#define LUA_CDIR	LUA_ROOT "lib/lua/" LUA_VDIR "/"
+
+#if !defined(LUA_PATH_DEFAULT)
+#define LUA_PATH_DEFAULT  \
+		LUA_LDIR"?.lua;"  LUA_LDIR"?/init.lua;" \
+		LUA_CDIR"?.lua;"  LUA_CDIR"?/init.lua;" \
+		"./?.lua;" "./?/init.lua"
+#endif
+
+#if !defined(LUA_CPATH_DEFAULT)
+#define LUA_CPATH_DEFAULT \
+		LUA_CDIR"?.so;" LUA_CDIR"loadall.so;" "./?.so"
+#endif
+
+#endif			/* } */
+
+
+/*
+@@ LUA_DIRSEP is the directory separator (for submodules).
+** CHANGE it if your machine does not use "/" as the directory separator
+** and is not Windows. (On Windows Lua automatically uses "\".)
+*/
+#if !defined(LUA_DIRSEP)
+
+#if defined(_WIN32)
+#define LUA_DIRSEP	"\\"
+#else
+#define LUA_DIRSEP	"/"
+#endif
+
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Marks for exported symbols in the C code
+** ===================================================================
+*/
+
+/*
+@@ LUA_API is a mark for all core API functions.
+@@ LUALIB_API is a mark for all auxiliary library functions.
+@@ LUAMOD_API is a mark for all standard library opening functions.
+** CHANGE them if you need to define those functions in some special way.
+** For instance, if you want to create one Windows DLL with the core and
+** the libraries, you may want to use the following definition (define
+** LUA_BUILD_AS_DLL to get it).
+*/
+#if defined(LUA_BUILD_AS_DLL)	/* { */
+
+#if defined(LUA_CORE) || defined(LUA_LIB)	/* { */
+#define LUA_API __declspec(dllexport)
+#else						/* }{ */
+#define LUA_API __declspec(dllimport)
+#endif						/* } */
+
+#else				/* }{ */
+
+#define LUA_API		extern
+
+#endif				/* } */
+
+
+/*
+** More often than not the libs go together with the core.
+*/
+#define LUALIB_API	LUA_API
+#define LUAMOD_API	LUA_API
+
+
+/*
+@@ LUAI_FUNC is a mark for all extern functions that are not to be
+** exported to outside modules.
+@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables,
+** none of which to be exported to outside modules (LUAI_DDEF for
+** definitions and LUAI_DDEC for declarations).
+** CHANGE them if you need to mark them in some special way. Elf/gcc
+** (versions 3.2 and later) mark them as "hidden" to optimize access
+** when Lua is compiled as a shared library. Not all elf targets support
+** this attribute. Unfortunately, gcc does not offer a way to check
+** whether the target offers that support, and those without support
+** give a warning about it. To avoid these warnings, change to the
+** default definition.
+*/
+#if defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \
+    defined(__ELF__)		/* { */
+#define LUAI_FUNC	__attribute__((visibility("internal"))) extern
+#else				/* }{ */
+#define LUAI_FUNC	extern
+#endif				/* } */
+
+#define LUAI_DDEC(dec)	LUAI_FUNC dec
+#define LUAI_DDEF	/* empty */
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Compatibility with previous versions
+** ===================================================================
+*/
+
+/*
+@@ LUA_COMPAT_5_3 controls other macros for compatibility with Lua 5.3.
+** You can define it to get all options, or change specific options
+** to fit your specific needs.
+*/
+#if defined(LUA_COMPAT_5_3)	/* { */
+
+/*
+@@ LUA_COMPAT_MATHLIB controls the presence of several deprecated
+** functions in the mathematical library.
+** (These functions were already officially removed in 5.3;
+** nevertheless they are still available here.)
+*/
+#define LUA_COMPAT_MATHLIB
+
+/*
+@@ LUA_COMPAT_APIINTCASTS controls the presence of macros for
+** manipulating other integer types (lua_pushunsigned, lua_tounsigned,
+** luaL_checkint, luaL_checklong, etc.)
+** (These macros were also officially removed in 5.3, but they are still
+** available here.)
+*/
+#define LUA_COMPAT_APIINTCASTS
+
+
+/*
+@@ LUA_COMPAT_LT_LE controls the emulation of the '__le' metamethod
+** using '__lt'.
+*/
+#define LUA_COMPAT_LT_LE
+
+
+/*
+@@ The following macros supply trivial compatibility for some
+** changes in the API. The macros themselves document how to
+** change your code to avoid using them.
+** (Once more, these macros were officially removed in 5.3, but they are
+** still available here.)
+*/
+#define lua_strlen(L,i)		lua_rawlen(L, (i))
+
+#define lua_objlen(L,i)		lua_rawlen(L, (i))
+
+#define lua_equal(L,idx1,idx2)		lua_compare(L,(idx1),(idx2),LUA_OPEQ)
+#define lua_lessthan(L,idx1,idx2)	lua_compare(L,(idx1),(idx2),LUA_OPLT)
+
+#endif				/* } */
+
+/* }================================================================== */
+
+
+
+/*
+** {==================================================================
+** Configuration for Numbers (low-level part).
+** Change these definitions if no predefined LUA_FLOAT_* / LUA_INT_*
+** satisfy your needs.
+** ===================================================================
+*/
+
+/*
+@@ LUAI_UACNUMBER is the result of a 'default argument promotion'
+@@ over a floating number.
+@@ l_floatatt(x) corrects float attribute 'x' to the proper float type
+** by prefixing it with one of FLT/DBL/LDBL.
+@@ LUA_NUMBER_FRMLEN is the length modifier for writing floats.
+@@ LUA_NUMBER_FMT is the format for writing floats.
+@@ lua_number2str converts a float to a string.
+@@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
+@@ l_floor takes the floor of a float.
+@@ lua_str2number converts a decimal numeral to a number.
+*/
+
+
+/* The following definitions are good for most cases here */
+
+#define l_floor(x)		(l_mathop(floor)(x))
+
+#define lua_number2str(s,sz,n)  \
+	l_sprintf((s), sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)(n))
+
+/*
+@@ lua_numbertointeger converts a float number with an integral value
+** to an integer, or returns 0 if float is not within the range of
+** a lua_Integer.  (The range comparisons are tricky because of
+** rounding. The tests here assume a two-complement representation,
+** where MININTEGER always has an exact representation as a float;
+** MAXINTEGER may not have one, and therefore its conversion to float
+** may have an ill-defined value.)
+*/
+#define lua_numbertointeger(n,p) \
+  ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \
+   (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \
+      (*(p) = (LUA_INTEGER)(n), 1))
+
+
+/* now the variable definitions */
+
+#if LUA_FLOAT_TYPE == LUA_FLOAT_FLOAT		/* { single float */
+
+#define LUA_NUMBER	float
+
+#define l_floatatt(n)		(FLT_##n)
+
+#define LUAI_UACNUMBER	double
+
+#define LUA_NUMBER_FRMLEN	""
+#define LUA_NUMBER_FMT		"%.7g"
+
+#define l_mathop(op)		op##f
+
+#define lua_str2number(s,p)	strtof((s), (p))
+
+
+#elif LUA_FLOAT_TYPE == LUA_FLOAT_LONGDOUBLE	/* }{ long double */
+
+#define LUA_NUMBER	long double
+
+#define l_floatatt(n)		(LDBL_##n)
+
+#define LUAI_UACNUMBER	long double
+
+#define LUA_NUMBER_FRMLEN	"L"
+#define LUA_NUMBER_FMT		"%.19Lg"
+
+#define l_mathop(op)		op##l
+
+#define lua_str2number(s,p)	strtold((s), (p))
+
+#elif LUA_FLOAT_TYPE == LUA_FLOAT_DOUBLE	/* }{ double */
+
+#define LUA_NUMBER	double
+
+#define l_floatatt(n)		(DBL_##n)
+
+#define LUAI_UACNUMBER	double
+
+#define LUA_NUMBER_FRMLEN	""
+#define LUA_NUMBER_FMT		"%.14g"
+
+#define l_mathop(op)		op
+
+#define lua_str2number(s,p)	strtod((s), (p))
+
+#else						/* }{ */
+
+#error "numeric float type not defined"
+
+#endif					/* } */
+
+
+
+/*
+@@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER.
+@@ LUAI_UACINT is the result of a 'default argument promotion'
+@@ over a LUA_INTEGER.
+@@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers.
+@@ LUA_INTEGER_FMT is the format for writing integers.
+@@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER.
+@@ LUA_MININTEGER is the minimum value for a LUA_INTEGER.
+@@ LUA_MAXUNSIGNED is the maximum value for a LUA_UNSIGNED.
+@@ lua_integer2str converts an integer to a string.
+*/
+
+
+/* The following definitions are good for most cases here */
+
+#define LUA_INTEGER_FMT		"%" LUA_INTEGER_FRMLEN "d"
+
+#define LUAI_UACINT		LUA_INTEGER
+
+#define lua_integer2str(s,sz,n)  \
+	l_sprintf((s), sz, LUA_INTEGER_FMT, (LUAI_UACINT)(n))
+
+/*
+** use LUAI_UACINT here to avoid problems with promotions (which
+** can turn a comparison between unsigneds into a signed comparison)
+*/
+#define LUA_UNSIGNED		unsigned LUAI_UACINT
+
+
+/* now the variable definitions */
+
+#if LUA_INT_TYPE == LUA_INT_INT		/* { int */
+
+#define LUA_INTEGER		int
+#define LUA_INTEGER_FRMLEN	""
+
+#define LUA_MAXINTEGER		INT_MAX
+#define LUA_MININTEGER		INT_MIN
+
+#define LUA_MAXUNSIGNED		UINT_MAX
+
+#elif LUA_INT_TYPE == LUA_INT_LONG	/* }{ long */
+
+#define LUA_INTEGER		long
+#define LUA_INTEGER_FRMLEN	"l"
+
+#define LUA_MAXINTEGER		LONG_MAX
+#define LUA_MININTEGER		LONG_MIN
+
+#define LUA_MAXUNSIGNED		ULONG_MAX
+
+#elif LUA_INT_TYPE == LUA_INT_LONGLONG	/* }{ long long */
+
+/* use presence of macro LLONG_MAX as proxy for C99 compliance */
+#if defined(LLONG_MAX)		/* { */
+/* use ISO C99 stuff */
+
+#define LUA_INTEGER		long long
+#define LUA_INTEGER_FRMLEN	"ll"
+
+#define LUA_MAXINTEGER		LLONG_MAX
+#define LUA_MININTEGER		LLONG_MIN
+
+#define LUA_MAXUNSIGNED		ULLONG_MAX
+
+#elif defined(LUA_USE_WINDOWS) /* }{ */
+/* in Windows, can use specific Windows types */
+
+#define LUA_INTEGER		__int64
+#define LUA_INTEGER_FRMLEN	"I64"
+
+#define LUA_MAXINTEGER		_I64_MAX
+#define LUA_MININTEGER		_I64_MIN
+
+#define LUA_MAXUNSIGNED		_UI64_MAX
+
+#else				/* }{ */
+
+#error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' \
+  or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)"
+
+#endif				/* } */
+
+#else				/* }{ */
+
+#error "numeric integer type not defined"
+
+#endif				/* } */
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Dependencies with C99 and other C details
+** ===================================================================
+*/
+
+/*
+@@ l_sprintf is equivalent to 'snprintf' or 'sprintf' in C89.
+** (All uses in Lua have only one format item.)
+*/
+#if !defined(LUA_USE_C89)
+#define l_sprintf(s,sz,f,i)	snprintf(s,sz,f,i)
+#else
+#define l_sprintf(s,sz,f,i)	((void)(sz), sprintf(s,f,i))
+#endif
+
+
+/*
+@@ lua_strx2number converts a hexadecimal numeral to a number.
+** In C99, 'strtod' does that conversion. Otherwise, you can
+** leave 'lua_strx2number' undefined and Lua will provide its own
+** implementation.
+*/
+#if !defined(LUA_USE_C89)
+#define lua_strx2number(s,p)		lua_str2number(s,p)
+#endif
+
+
+/*
+@@ lua_pointer2str converts a pointer to a readable string in a
+** non-specified way.
+*/
+#define lua_pointer2str(buff,sz,p)	l_sprintf(buff,sz,"%p",p)
+
+
+/*
+@@ lua_number2strx converts a float to a hexadecimal numeral.
+** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
+** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
+** provide its own implementation.
+*/
+#if !defined(LUA_USE_C89)
+#define lua_number2strx(L,b,sz,f,n)  \
+	((void)L, l_sprintf(b,sz,f,(LUAI_UACNUMBER)(n)))
+#endif
+
+
+/*
+** 'strtof' and 'opf' variants for math functions are not valid in
+** C89. Otherwise, the macro 'HUGE_VALF' is a good proxy for testing the
+** availability of these variants. ('math.h' is already included in
+** all files that use these macros.)
+*/
+#if defined(LUA_USE_C89) || (defined(HUGE_VAL) && !defined(HUGE_VALF))
+#undef l_mathop  /* variants not available */
+#undef lua_str2number
+#define l_mathop(op)		(lua_Number)op  /* no variant */
+#define lua_str2number(s,p)	((lua_Number)strtod((s), (p)))
+#endif
+
+
+/*
+@@ LUA_KCONTEXT is the type of the context ('ctx') for continuation
+** functions.  It must be a numerical type; Lua will use 'intptr_t' if
+** available, otherwise it will use 'ptrdiff_t' (the nearest thing to
+** 'intptr_t' in C89)
+*/
+#define LUA_KCONTEXT	ptrdiff_t
+
+#if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \
+    __STDC_VERSION__ >= 199901L
+#include <stdint.h>
+#if defined(INTPTR_MAX)  /* even in C99 this type is optional */
+#undef LUA_KCONTEXT
+#define LUA_KCONTEXT	intptr_t
+#endif
+#endif
+
+
+/*
+@@ lua_getlocaledecpoint gets the locale "radix character" (decimal point).
+** Change that if you do not want to use C locales. (Code using this
+** macro must include the header 'locale.h'.)
+*/
+#if !defined(lua_getlocaledecpoint)
+#define lua_getlocaledecpoint()		(localeconv()->decimal_point[0])
+#endif
+
+
+/*
+** macros to improve jump prediction, used mostly for error handling
+** and debug facilities. (Some macros in the Lua API use these macros.
+** Define LUA_NOBUILTIN if you do not want '__builtin_expect' in your
+** code.)
+*/
+#if !defined(luai_likely)
+
+#if defined(__GNUC__) && !defined(LUA_NOBUILTIN)
+#define luai_likely(x)		(__builtin_expect(((x) != 0), 1))
+#define luai_unlikely(x)	(__builtin_expect(((x) != 0), 0))
+#else
+#define luai_likely(x)		(x)
+#define luai_unlikely(x)	(x)
+#endif
+
+#endif
+
+
+#if defined(LUA_CORE) || defined(LUA_LIB)
+/* shorter names for Lua's own use */
+#define l_likely(x)	luai_likely(x)
+#define l_unlikely(x)	luai_unlikely(x)
+#endif
+
+
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Language Variations
+** =====================================================================
+*/
+
+/*
+@@ LUA_NOCVTN2S/LUA_NOCVTS2N control how Lua performs some
+** coercions. Define LUA_NOCVTN2S to turn off automatic coercion from
+** numbers to strings. Define LUA_NOCVTS2N to turn off automatic
+** coercion from strings to numbers.
+*/
+/* #define LUA_NOCVTN2S */
+/* #define LUA_NOCVTS2N */
+
+
+/*
+@@ LUA_USE_APICHECK turns on several consistency checks on the C API.
+** Define it as a help when debugging C code.
+*/
+#if defined(LUA_USE_APICHECK)
+#include <assert.h>
+#define luai_apicheck(l,e)	assert(e)
+#endif
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Macros that affect the API and must be stable (that is, must be the
+** same when you compile Lua and when you compile code that links to
+** Lua).
+** =====================================================================
+*/
+
+/*
+@@ LUAI_MAXSTACK limits the size of the Lua stack.
+** CHANGE it if you need a different limit. This limit is arbitrary;
+** its only purpose is to stop Lua from consuming unlimited stack
+** space (and to reserve some numbers for pseudo-indices).
+** (It must fit into max(size_t)/32.)
+*/
+#if LUAI_IS32INT
+#define LUAI_MAXSTACK		1000000
+#else
+#define LUAI_MAXSTACK		15000
+#endif
+
+
+/*
+@@ LUA_EXTRASPACE defines the size of a raw memory area associated with
+** a Lua state with very fast access.
+** CHANGE it if you need a different size.
+*/
+#define LUA_EXTRASPACE		(sizeof(void *))
+
+
+/*
+@@ LUA_IDSIZE gives the maximum size for the description of the source
+@@ of a function in debug information.
+** CHANGE it if you want a different size.
+*/
+#define LUA_IDSIZE	60
+
+
+/*
+@@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system.
+*/
+#define LUAL_BUFFERSIZE   ((int)(16 * sizeof(void*) * sizeof(lua_Number)))
+
+
+/*
+@@ LUAI_MAXALIGN defines fields that, when used in a union, ensure
+** maximum alignment for the other items in that union.
+*/
+#define LUAI_MAXALIGN  lua_Number n; double u; void *s; lua_Integer i; long l
+
+/* }================================================================== */
+
+
+
+
+
+/* =================================================================== */
+
+/*
+** Local configuration. You can use this space to add your redefinitions
+** without modifying the main part of the file.
+*/
+
+
+
+#include <luaconf.local.h>
+
+#endif
+
diff --git a/contrib/lua/src/luaconf.h.dist b/contrib/lua/src/luaconf.h.dist
index b515396673d8..acb59c51f59c 100644
--- a/contrib/lua/src/luaconf.h.dist
+++ b/contrib/lua/src/luaconf.h.dist
@@ -16,13 +16,13 @@
 ** ===================================================================
 ** General Configuration File for Lua
 **
-** Some definitions here can be changed externally, through the
-** compiler (e.g., with '-D' options). Those are protected by
-** '#if !defined' guards. However, several other definitions should
-** be changed directly here, either because they affect the Lua
-** ABI (by making the changes here, you ensure that all software
-** connected to Lua, such as C libraries, will be compiled with the
-** same configuration); or because they are seldom changed.
+** Some definitions here can be changed externally, through the compiler
+** (e.g., with '-D' options): They are commented out or protected
+** by '#if !defined' guards. However, several other definitions
+** should be changed directly here, either because they affect the
+** Lua ABI (by making the changes here, you ensure that all software
+** connected to Lua, such as C libraries, will be compiled with the same
+** configuration); or because they are seldom changed.
 **
 ** Search for "@@" to find all configurable definitions.
 ** ===================================================================
@@ -81,27 +81,13 @@
 
 /*
 ** {==================================================================
-** Configuration for Number types.
+** Configuration for Number types. These options should not be
+** set externally, because any other code connected to Lua must
+** use the same configuration.
 ** ===================================================================
 */
 
 /*
-@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats.
-*/
-/* #define LUA_32BITS */
-
-
-/*
-@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
-** C89 ('long' and 'double'); Windows always has '__int64', so it does
-** not need to use this case.
-*/
-#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
-#define LUA_C89_NUMBERS
-#endif
-
-
-/*
 @@ LUA_INT_TYPE defines the type for Lua integers.
 @@ LUA_FLOAT_TYPE defines the type for Lua floats.
 ** Lua should work fine with any mix of these options supported
@@ -122,7 +108,31 @@
 #define LUA_FLOAT_LONGDOUBLE	3
 #define LUA_FLOAT_INT64		4
 
-#if defined(LUA_32BITS)		/* { */
+
+/* Default configuration ('long long' and 'double', for 64-bit Lua) */
+#define LUA_INT_DEFAULT		LUA_INT_LONGLONG
+#define LUA_FLOAT_DEFAULT	LUA_FLOAT_DOUBLE
+
+
+/*
+@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats.
+*/
+#define LUA_32BITS	0
+
+
+/*
+@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
+** C89 ('long' and 'double'); Windows always has '__int64', so it does
+** not need to use this case.
+*/
+#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
+#define LUA_C89_NUMBERS		1
+#else
+#define LUA_C89_NUMBERS		0
+#endif
+
+
+#if LUA_32BITS		/* { */
 /*
 ** 32-bit integers and 'float'
 */
@@ -133,26 +143,21 @@
 #endif
 #define LUA_FLOAT_TYPE	LUA_FLOAT_FLOAT
 
-#elif defined(LUA_C89_NUMBERS)	/* }{ */
+#elif LUA_C89_NUMBERS	/* }{ */
 /*
 ** largest types available for C89 ('long' and 'double')
 */
 #define LUA_INT_TYPE	LUA_INT_LONG
 #define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
 
-#endif				/* } */
+#else		/* }{ */
+/* use defaults */
 
+#define LUA_INT_TYPE	LUA_INT_DEFAULT
+#define LUA_FLOAT_TYPE	LUA_FLOAT_DEFAULT
 
-/*
-** default configuration for 64-bit Lua ('long long' and 'double')
-*/
-#if !defined(LUA_INT_TYPE)
-#define LUA_INT_TYPE	LUA_INT_LONGLONG
-#endif
+#endif				/* } */
 
-#if !defined(LUA_FLOAT_TYPE)
-#define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
-#endif
 
 /* }================================================================== */
 
@@ -374,14 +379,13 @@
 
 /*
 ** {==================================================================
-** Configuration for Numbers.
+** Configuration for Numbers (low-level part).
 ** Change these definitions if no predefined LUA_FLOAT_* / LUA_INT_*
 ** satisfy your needs.
 ** ===================================================================
 */
 
 /*
-@@ LUA_NUMBER is the floating-point type used by Lua.
 @@ LUAI_UACNUMBER is the result of a 'default argument promotion'
 @@ over a floating number.
 @@ l_floatatt(x) corrects float attribute 'x' to the proper float type
@@ -474,10 +478,7 @@
 
 
 /*
-@@ LUA_INTEGER is the integer type used by Lua.
-**
 @@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER.
-**
 @@ LUAI_UACINT is the result of a 'default argument promotion'
 @@ over a LUA_INTEGER.
 @@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers.
@@ -485,7 +486,6 @@
 @@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER.
 @@ LUA_MININTEGER is the minimum value for a LUA_INTEGER.
 @@ LUA_MAXUNSIGNED is the maximum value for a LUA_UNSIGNED.
-@@ LUA_UNSIGNEDBITS is the number of bits in a LUA_UNSIGNED.
 @@ lua_integer2str converts an integer to a string.
 */
 
@@ -506,9 +506,6 @@
 #define LUA_UNSIGNED		unsigned LUAI_UACINT
 
 
-#define LUA_UNSIGNEDBITS	(sizeof(LUA_UNSIGNED) * CHAR_BIT)
-
-
 /* now the variable definitions */
 
 #if LUA_INT_TYPE == LUA_INT_INT		/* { int */
@@ -660,6 +657,34 @@
 #define lua_getlocaledecpoint()		(localeconv()->decimal_point[0])
 #endif
 
+
+/*
+** macros to improve jump prediction, used mostly for error handling
+** and debug facilities. (Some macros in the Lua API use these macros.
+** Define LUA_NOBUILTIN if you do not want '__builtin_expect' in your
+** code.)
+*/
+#if !defined(luai_likely)
+
+#if defined(__GNUC__) && !defined(LUA_NOBUILTIN)
+#define luai_likely(x)		(__builtin_expect(((x) != 0), 1))
+#define luai_unlikely(x)	(__builtin_expect(((x) != 0), 0))
+#else
+#define luai_likely(x)		(x)
+#define luai_unlikely(x)	(x)
+#endif
+
+#endif
+
+
+#if defined(LUA_CORE) || defined(LUA_LIB)
+/* shorter names for Lua's own use */
+#define l_likely(x)	luai_likely(x)
+#define l_unlikely(x)	luai_unlikely(x)
+#endif
+
+
+
 /* }================================================================== */
 
 
diff --git a/contrib/lua/src/lualib.h b/contrib/lua/src/lualib.h
index eb08b530a60d..2625529076a8 100644
--- a/contrib/lua/src/lualib.h
+++ b/contrib/lua/src/lualib.h
@@ -49,10 +49,4 @@ LUAMOD_API int (luaopen_package) (lua_State *L);
 LUALIB_API void (luaL_openlibs) (lua_State *L);
 
 
-
-#if !defined(lua_assert)
-#define lua_assert(x)	((void)0)
-#endif
-
-
 #endif
diff --git a/contrib/lua/src/lutf8lib.c b/contrib/lua/src/lutf8lib.c
index 901d985f8d8c..e7bf098f6d04 100644
--- a/contrib/lua/src/lutf8lib.c
+++ b/contrib/lua/src/lutf8lib.c
@@ -224,14 +224,11 @@ static int byteoffset (lua_State *L) {
 static int iter_aux (lua_State *L, int strict) {
   size_t len;
   const char *s = luaL_checklstring(L, 1, &len);
-  lua_Integer n = lua_tointeger(L, 2) - 1;
-  if (n < 0)  /* first iteration? */
-    n = 0;  /* start from here */
-  else if (n < (lua_Integer)len) {
-    n++;  /* skip current byte */
-    while (iscont(s + n)) n++;  /* and its continuations */
+  lua_Unsigned n = (lua_Unsigned)lua_tointeger(L, 2);
+  if (n < len) {
+    while (iscont(s + n)) n++;  /* skip continuation bytes */
   }
-  if (n >= (lua_Integer)len)
+  if (n >= len)  /* (also handles original 'n' being negative) */
     return 0;  /* no more codepoints */
   else {
     utfint code;
diff --git a/contrib/lua/src/lvm.c b/contrib/lua/src/lvm.c
index 02c1b588a371..2da6b2c0e792 100644
--- a/contrib/lua/src/lvm.c
+++ b/contrib/lua/src/lvm.c
@@ -52,8 +52,10 @@
 /*
 ** 'l_intfitsf' checks whether a given integer is in the range that
 ** can be converted to a float without rounding. Used in comparisons.
+** May be defined in luaconf.h if this test is incorrect for custom
+** LUA_FLOAT_TYPEs.
 */
-#if !defined(l_intfitsf) && LUA_FLOAT_TYPE != LUA_FLOAT_INT64
+#if !defined(l_intfitsf)
 
 /* number of bits in the mantissa of a float */
 #define NBM		(l_floatatt(MANT_DIG))
@@ -80,12 +82,7 @@
 
 #endif
 
-#endif /* !defined(l_intfitsf) && LUA_FLOAT_TYPE != LUA_FLOAT_INT64 */
-
-#ifndef l_intfitsf
-#define l_intfitsf(i)	1
-#endif
-
+#endif /* !defined(l_intfitsf) */
 
 /*
 ** Try to convert a value from string to a number value.
@@ -242,11 +239,11 @@ static int forprep (lua_State *L, StkId ra) {
   }
   else {  /* try making all values floats */
     lua_Number init; lua_Number limit; lua_Number step;
-    if (unlikely(!tonumber(plimit, &limit)))
+    if (l_unlikely(!tonumber(plimit, &limit)))
       luaG_forerror(L, plimit, "limit");
-    if (unlikely(!tonumber(pstep, &step)))
+    if (l_unlikely(!tonumber(pstep, &step)))
       luaG_forerror(L, pstep, "step");
-    if (unlikely(!tonumber(pinit, &init)))
+    if (l_unlikely(!tonumber(pinit, &init)))
       luaG_forerror(L, pinit, "initial value");
     if (step == 0)
       luaG_runerror(L, "'for' step is zero");
@@ -299,7 +296,7 @@ void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
     if (slot == NULL) {  /* 't' is not a table? */
       lua_assert(!ttistable(t));
       tm = luaT_gettmbyobj(L, t, TM_INDEX);
-      if (unlikely(notm(tm)))
+      if (l_unlikely(notm(tm)))
         luaG_typeerror(L, t, "index");  /* no metamethod */
       /* else will try the metamethod */
     }
@@ -344,10 +341,7 @@ void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
       lua_assert(isempty(slot));  /* slot must be empty */
       tm = fasttm(L, h->metatable, TM_NEWINDEX);  /* get metamethod */
       if (tm == NULL) {  /* no metamethod? */
-        if (isabstkey(slot))  /* no previous entry? */
-          slot = luaH_newkey(L, h, key);  /* create one */
-        /* no metamethod and (now) there is an entry with given key */
-        setobj2t(L, cast(TValue *, slot), val);  /* set its new value */
+        luaH_finishset(L, h, key, slot, val);  /* set new value */
         invalidateTMcache(h);
         luaC_barrierback(L, obj2gco(h), val);
         return;
@@ -356,7 +350,7 @@ void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
     }
     else {  /* not a table; check metamethod */
       tm = luaT_gettmbyobj(L, t, TM_NEWINDEX);
-      if (unlikely(notm(tm)))
+      if (l_unlikely(notm(tm)))
         luaG_typeerror(L, t, "index");
     }
     /* try the metamethod */
@@ -416,7 +410,7 @@ static int l_strcmp (const TString *ls, const TString *rs) {
 ** from float to int.)
 ** When 'f' is NaN, comparisons must result in false.
 */
-static int LTintfloat (lua_Integer i, lua_Number f) {
+l_sinline int LTintfloat (lua_Integer i, lua_Number f) {
   if (l_intfitsf(i))
     return luai_numlt(cast_num(i), f);  /* compare them as floats */
   else {  /* i < f <=> i < ceil(f) */
@@ -433,7 +427,7 @@ static int LTintfloat (lua_Integer i, lua_Number f) {
 ** Check whether integer 'i' is less than or equal to float 'f'.
 ** See comments on previous function.
 */
-static int LEintfloat (lua_Integer i, lua_Number f) {
+l_sinline int LEintfloat (lua_Integer i, lua_Number f) {
   if (l_intfitsf(i))
     return luai_numle(cast_num(i), f);  /* compare them as floats */
   else {  /* i <= f <=> i <= floor(f) */
@@ -450,7 +444,7 @@ static int LEintfloat (lua_Integer i, lua_Number f) {
 ** Check whether float 'f' is less than integer 'i'.
 ** See comments on previous function.
 */
-static int LTfloatint (lua_Number f, lua_Integer i) {
+l_sinline int LTfloatint (lua_Number f, lua_Integer i) {
   if (l_intfitsf(i))
     return luai_numlt(f, cast_num(i));  /* compare them as floats */
   else {  /* f < i <=> floor(f) < i */
@@ -467,7 +461,7 @@ static int LTfloatint (lua_Number f, lua_Integer i) {
 ** Check whether float 'f' is less than or equal to integer 'i'.
 ** See comments on previous function.
 */
-static int LEfloatint (lua_Number f, lua_Integer i) {
+l_sinline int LEfloatint (lua_Number f, lua_Integer i) {
   if (l_intfitsf(i))
     return luai_numle(f, cast_num(i));  /* compare them as floats */
   else {  /* f <= i <=> ceil(f) <= i */
@@ -483,7 +477,7 @@ static int LEfloatint (lua_Number f, lua_Integer i) {
 /*
 ** Return 'l < r', for numbers.
 */
-static int LTnum (const TValue *l, const TValue *r) {
+l_sinline int LTnum (const TValue *l, const TValue *r) {
   lua_assert(ttisnumber(l) && ttisnumber(r));
   if (ttisinteger(l)) {
     lua_Integer li = ivalue(l);
@@ -505,7 +499,7 @@ static int LTnum (const TValue *l, const TValue *r) {
 /*
 ** Return 'l <= r', for numbers.
 */
-static int LEnum (const TValue *l, const TValue *r) {
+l_sinline int LEnum (const TValue *l, const TValue *r) {
   lua_assert(ttisnumber(l) && ttisnumber(r));
   if (ttisinteger(l)) {
     lua_Integer li = ivalue(l);
@@ -578,8 +572,13 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
     if (ttype(t1) != ttype(t2) || ttype(t1) != LUA_TNUMBER)
       return 0;  /* only numbers can be equal with different variants */
     else {  /* two numbers with different variants */
-      lua_Integer i1, i2;  /* compare them as integers */
-      return (tointegerns(t1, &i1) && tointegerns(t2, &i2) && i1 == i2);
+      /* One of them is an integer. If the other does not have an
+         integer value, they cannot be equal; otherwise, compare their
+         integer values. */
+      lua_Integer i1, i2;
+      return (luaV_tointegerns(t1, &i1, F2Ieq) &&
+              luaV_tointegerns(t2, &i2, F2Ieq) &&
+              i1 == i2);
     }
   }
   /* values have same type and same variant */
@@ -661,7 +660,7 @@ void luaV_concat (lua_State *L, int total) {
       /* collect total length and number of strings */
       for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) {
         size_t l = vslen(s2v(top - n - 1));
-        if (unlikely(l >= (MAX_SIZE/sizeof(char)) - tl))
+        if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl))
           luaG_runerror(L, "string length overflow");
         tl += l;
       }
@@ -705,7 +704,7 @@ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
     }
     default: {  /* try metamethod */
       tm = luaT_gettmbyobj(L, rb, TM_LEN);
-      if (unlikely(notm(tm)))  /* no metamethod? */
+      if (l_unlikely(notm(tm)))  /* no metamethod? */
         luaG_typeerror(L, rb, "get length of");
       break;
     }
@@ -721,7 +720,7 @@ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
 ** otherwise 'floor(q) == trunc(q) - 1'.
 */
 lua_Integer luaV_idiv (lua_State *L, lua_Integer m, lua_Integer n) {
-  if (unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
+  if (l_unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
     if (n == 0)
       luaG_runerror(L, "attempt to divide by zero");
     return intop(-, 0, m);   /* n==-1; avoid overflow with 0x80000...//-1 */
@@ -741,7 +740,7 @@ lua_Integer luaV_idiv (lua_State *L, lua_Integer m, lua_Integer n) {
 ** about luaV_idiv.)
 */
 lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
-  if (unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
+  if (l_unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
     if (n == 0)
       luaG_runerror(L, "attempt to perform 'n%%0'");
     return 0;   /* m % -1 == 0; avoid overflow with 0x80000...%-1 */
@@ -771,7 +770,8 @@ lua_Number luaV_modf (lua_State *L, lua_Number m, lua_Number n) {
 /*
 ** Shift left operation. (Shift right just negates 'y'.)
 */
-#define luaV_shiftr(x,y)	luaV_shiftl(x,-(y))
+#define luaV_shiftr(x,y)	luaV_shiftl(x,intop(-, 0, y))
+
 
 lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
   if (y < 0) {  /* shift right? */
@@ -852,6 +852,19 @@ void luaV_finishOp (lua_State *L) {
       luaV_concat(L, total);  /* concat them (may yield again) */
       break;
     }
+    case OP_CLOSE: {  /* yielded closing variables */
+      ci->u.l.savedpc--;  /* repeat instruction to close other vars. */
+      break;
+    }
+    case OP_RETURN: {  /* yielded closing variables */
+      StkId ra = base + GETARG_A(inst);
+      /* adjust top to signal correct number of returns, in case the
+         return is "up to top" ('isIT') */
+      L->top = ra + ci->u2.nres;
+      /* repeat instruction to close other vars. and complete the return */
+      ci->u.l.savedpc--;
+      break;
+    }
     default: {
       /* only these other opcodes can yield */
       lua_assert(op == OP_TFORCALL || op == OP_CALL ||
@@ -927,7 +940,7 @@ void luaV_finishOp (lua_State *L) {
 */
 #define op_arithfK(L,fop) {  \
   TValue *v1 = vRB(i);  \
-  TValue *v2 = KC(i);  \
+  TValue *v2 = KC(i); lua_assert(ttisnumber(v2));  \
   op_arithf_aux(L, v1, v2, fop); }
 
 
@@ -956,7 +969,7 @@ void luaV_finishOp (lua_State *L) {
 */
 #define op_arithK(L,iop,fop) {  \
   TValue *v1 = vRB(i);  \
-  TValue *v2 = KC(i);  \
+  TValue *v2 = KC(i); lua_assert(ttisnumber(v2));  \
   op_arith_aux(L, v1, v2, iop, fop); }
 
 
@@ -1055,7 +1068,8 @@ void luaV_finishOp (lua_State *L) {
 #define updatebase(ci)	(base = ci->func + 1)
 
 
-#define updatestack(ci) { if (trap) { updatebase(ci); ra = RA(i); } }
+#define updatestack(ci)  \
+	{ if (l_unlikely(trap)) { updatebase(ci); ra = RA(i); } }
 
 
 /*
@@ -1099,7 +1113,7 @@ void luaV_finishOp (lua_State *L) {
 #define ProtectNT(exp)  (savepc(L), (exp), updatetrap(ci))
 
 /*
-** Protect code that can only raise errors. (That is, it cannnot change
+** Protect code that can only raise errors. (That is, it cannot change
 ** the stack or hooks.)
 */
 #define halfProtect(exp)  (savestate(L,ci), (exp))
@@ -1113,7 +1127,7 @@ void luaV_finishOp (lua_State *L) {
 
 /* fetch an instruction and prepare its execution */
 #define vmfetch()	{ \
-  if (trap) {  /* stack reallocation or hooks? */ \
+  if (l_unlikely(trap)) {  /* stack reallocation or hooks? */ \
     trap = luaG_traceexec(L, pc);  /* handle hooks */ \
     updatebase(ci);  /* correct stack */ \
   } \
@@ -1141,7 +1155,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
   cl = clLvalue(s2v(ci->func));
   k = cl->p->k;
   pc = ci->u.l.savedpc;
-  if (trap) {
+  if (l_unlikely(trap)) {
     if (pc == cl->p->code) {  /* first instruction (not resuming)? */
       if (cl->p->is_vararg)
         trap = 0;  /* hooks will start after VARARGPREP instruction */
@@ -1156,6 +1170,10 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
     Instruction i;  /* instruction being executed */
     StkId ra;  /* instruction's A register */
     vmfetch();
+    #if 0
+      /* low-level line tracing for debugging Lua */
+      printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p)));
+    #endif
     lua_assert(base == ci->func + 1);
     lua_assert(base <= L->top && L->top < L->stack_last);
     /* invalidate top for instructions not expecting it */
@@ -1534,7 +1552,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
         vmbreak;
       }
       vmcase(OP_CLOSE) {
-        Protect(luaF_close(L, ra, LUA_OK));
+        Protect(luaF_close(L, ra, LUA_OK, 1));
         vmbreak;
       }
       vmcase(OP_TBC) {
@@ -1623,13 +1641,13 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
           updatetrap(ci);  /* C call; nothing else to be done */
         else {  /* Lua call: run function in this same C frame */
           ci = newci;
-          ci->callstatus = 0;  /* call re-uses 'luaV_execute' */
           goto startfunc;
         }
         vmbreak;
       }
       vmcase(OP_TAILCALL) {
         int b = GETARG_B(i);  /* number of arguments + 1 (function) */
+        int n;  /* number of results when calling a C function */
         int nparams1 = GETARG_C(i);
         /* delta is virtual 'func' - real 'func' (vararg functions) */
         int delta = (nparams1) ? ci->u.l.nextraargs + nparams1 : 0;
@@ -1639,29 +1657,18 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
           b = cast_int(L->top - ra);
         savepc(ci);  /* several calls here can raise errors */
         if (TESTARG_k(i)) {
-          /* close upvalues from current call; the compiler ensures
-             that there are no to-be-closed variables here, so this
-             call cannot change the stack */
-          luaF_close(L, base, NOCLOSINGMETH);
+          luaF_closeupval(L, base);  /* close upvalues from current call */
+          lua_assert(L->tbclist < base);  /* no pending tbc variables */
           lua_assert(base == ci->func + 1);
         }
-        while (!ttisfunction(s2v(ra))) {  /* not a function? */
-          luaD_tryfuncTM(L, ra);  /* try '__call' metamethod */
-          b++;  /* there is now one extra argument */
-          checkstackGCp(L, 1, ra);
-        }
-        if (!ttisLclosure(s2v(ra))) {  /* C function? */
-          luaD_precall(L, ra, LUA_MULTRET);  /* call it */
-          updatetrap(ci);
-          updatestack(ci);  /* stack may have been relocated */
+        if ((n = luaD_pretailcall(L, ci, ra, b, delta)) < 0)  /* Lua function? */
+          goto startfunc;  /* execute the callee */
+        else {  /* C function? */
           ci->func -= delta;  /* restore 'func' (if vararg) */
-          luaD_poscall(L, ci, cast_int(L->top - ra));  /* finish caller */
+          luaD_poscall(L, ci, n);  /* finish caller */
           updatetrap(ci);  /* 'luaD_poscall' can change hooks */
           goto ret;  /* caller returns after the tail call */
         }
-        ci->func -= delta;  /* restore 'func' (if vararg) */
-        luaD_pretailcall(L, ci, ra, b);  /* prepare call frame */
-        goto startfunc;  /* execute the callee */
       }
       vmcase(OP_RETURN) {
         int n = GETARG_B(i) - 1;  /* number of results */
@@ -1670,9 +1677,10 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
           n = cast_int(L->top - ra);  /* get what is available */
         savepc(ci);
         if (TESTARG_k(i)) {  /* may there be open upvalues? */
+          ci->u2.nres = n;  /* save number of returns */
           if (L->top < ci->top)
             L->top = ci->top;
-          luaF_close(L, base, LUA_OK);
+          luaF_close(L, base, CLOSEKTOP, 1);
           updatetrap(ci);
           updatestack(ci);
         }
@@ -1684,23 +1692,23 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
         goto ret;
       }
       vmcase(OP_RETURN0) {
-        if (L->hookmask) {
+        if (l_unlikely(L->hookmask)) {
           L->top = ra;
           savepc(ci);
           luaD_poscall(L, ci, 0);  /* no hurry... */
           trap = 1;
         }
         else {  /* do the 'poscall' here */
-          int nres = ci->nresults;
+          int nres;
           L->ci = ci->previous;  /* back to caller */
           L->top = base - 1;
-          while (nres-- > 0)
+          for (nres = ci->nresults; l_unlikely(nres > 0); nres--)
             setnilvalue(s2v(L->top++));  /* all results are nil */
         }
         goto ret;
       }
       vmcase(OP_RETURN1) {
-        if (L->hookmask) {
+        if (l_unlikely(L->hookmask)) {
           L->top = ra + 1;
           savepc(ci);
           luaD_poscall(L, ci, 1);  /* no hurry... */
@@ -1714,8 +1722,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
           else {
             setobjs2s(L, base - 1, ra);  /* at least this result */
             L->top = base;
-            while (--nres > 0)  /* complete missing results */
-              setnilvalue(s2v(L->top++));
+            for (; l_unlikely(nres > 1); nres--)
+              setnilvalue(s2v(L->top++));  /* complete missing results */
           }
         }
        ret:  /* return from a Lua function */
@@ -1818,7 +1826,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
       }
       vmcase(OP_VARARGPREP) {
         ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p));
-        if (trap) {
+        if (l_unlikely(trap)) {  /* previous "Protect" updated trap */
           luaD_hookcall(L, ci);
           L->oldpc = 1;  /* next opcode will be seen as a "new" line */
         }
diff --git a/contrib/lua/src/lvm.h b/contrib/lua/src/lvm.h
index 2d4ac160fefd..1bc16f3a50ba 100644
--- a/contrib/lua/src/lvm.h
+++ b/contrib/lua/src/lvm.h
@@ -60,12 +60,14 @@ typedef enum {
 
 /* convert an object to an integer (including string coercion) */
 #define tointeger(o,i) \
-  (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointeger(o,i,LUA_FLOORN2I))
+  (l_likely(ttisinteger(o)) ? (*(i) = ivalue(o), 1) \
+                          : luaV_tointeger(o,i,LUA_FLOORN2I))
 
 
 /* convert an object to an integer (without string coercion) */
 #define tointegerns(o,i) \
-  (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointegerns(o,i,LUA_FLOORN2I))
+  (l_likely(ttisinteger(o)) ? (*(i) = ivalue(o), 1) \
+                          : luaV_tointegerns(o,i,LUA_FLOORN2I))
 
 
 #define intop(op,v1,v2) l_castU2S(l_castS2U(v1) op l_castS2U(v2))
diff --git a/lib/liblua/luaconf.local.h b/lib/liblua/luaconf.local.h
new file mode 100644
index 000000000000..8f3fef15ddca
--- /dev/null
+++ b/lib/liblua/luaconf.local.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023, Netflix, Inc
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+/*
+ * We need to always define this. For the boot loader, we use it. For flua
+ * we don't, but it needs to be defined to keep some ifdefs happy.
+ */
+#define LUA_FLOAT_INT64		4
+
+#define LUA_USE_POSIX
+#ifndef BOOTSTRAPPING
+#define LUA_USE_DLOPEN
+#endif
+
+#undef LUA_ROOT
+#undef LUA_LDIR
+#undef LUA_CDIR
+#define LUA_ROOT	"/usr/"
+#define LUA_LDIR	LUA_ROOT "share/flua/"
+#define LUA_CDIR	LUA_ROOT "lib/flua/"
diff --git a/stand/liblua/luaconf.local.h b/stand/liblua/luaconf.local.h
new file mode 100644
index 000000000000..7da3d6bddc6e
--- /dev/null
+++ b/stand/liblua/luaconf.local.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2023, Netflix, Inc
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+/*
+ * We need to always define this. For the boot loader, we use it. For flua
+ * we don't, but it needs to be defined to keep some ifdefs happy.
+ */
+#define LUA_FLOAT_INT64		4
+
+/* set the paths we want */
+#undef LUA_ROOT
+#undef LUA_LDIR
+#undef LUA_CDIR
+#define LUA_ROOT       LUA_PATH "/" LUA_VDIR "/"
+#define LUA_LDIR       LUA_ROOT "share/"
+#define LUA_CDIR       LUA_ROOT "lib/"
+
+/* Simplify this, since it's always an int */
+#undef lua_numbertointeger
+#define lua_numbertointeger(n,p) \
+      (*(p) = (LUA_INTEGER)(n), 1)
+
+/* Define our number type by brute force, but first undo the default defines */
+#undef panic
+#undef LUA_NUMBER
+#undef l_floatatt
+#undef LUAI_UACNUMBER
+#undef LUA_NUMBER_FRMLEN
+#undef LUA_NUMBER_FMT
+#undef l_mathop
+#undef lua_str2number
+#undef lua_getlocaledecpoint
+
+#undef LUA_FLOAT_TYPE
+#define LUA_FLOAT_TYPE LUA_FLOAT_INT64
+
+#include "lstd.h"
+
+#include <machine/_inttypes.h>
+
+#define panic lua_panic
+/* Hack to use int64 as the LUA_NUMBER from ZFS code, kinda */
+
+#define LUA_NUMBER	int64_t
+
+#define l_floatatt(n)		(LUA_FLOAT_INT_HACK_##n)
+#define LUA_FLOAT_INT_HACK_MANT_DIG	32
+#define LUA_FLOAT_INT_HACK_MAX_10_EXP	32
+
+#define LUAI_UACNUMBER	int64_t
+
+#define LUA_NUMBER_FRMLEN	""
+#define LUA_NUMBER_FMT		"%" PRId64
+
+#define l_mathop(x)		(lstd_ ## x)
+
+#define lua_str2number(s,p)	strtoll((s), (p), 0)
+
+#define lua_getlocaledecpoint()		'.'
+
+/* Better buffer size */
+#undef LUAL_BUFFERSIZE
+#define LUAL_BUFFERSIZE		128
+
+/* Maxalign can't reference double */
+#undef LUAI_MAXALIGN
+#define LUAI_MAXALIGN  lua_Number n; void *s; lua_Integer i; long l
+
+#define LUA_AVOID_FLOAT
diff --git a/stand/lua.mk b/stand/lua.mk
index 711d95e48ba0..021ce73bd60f 100644
--- a/stand/lua.mk
+++ b/stand/lua.mk
@@ -3,4 +3,3 @@
 # Common flags to build lua related files
 
 CFLAGS+=	-I${LUASRC} -I${LDRSRC} -I${LIBLUASRC}
-CFLAGS+=	-DLUA_FLOAT_TYPE=LUA_FLOAT_INT64