update Lua.

18 files changed, 270 insertions, 218 deletions

diff --git a/src/lua/lapi.c b/src/lua/lapi.c
index c824da2..03e756d 100644
--- a/src/lua/lapi.c
+++ b/src/lua/lapi.c
@@ -629,11 +629,21 @@ 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);
 }
 
 
@@ -811,10 +821,10 @@ 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 +871,10 @@ 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 +1071,7 @@ 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);
diff --git a/src/lua/lauxlib.c b/src/lua/lauxlib.c
index cbe9ed3..074ff08 100644
--- a/src/lua/lauxlib.c
+++ b/src/lua/lauxlib.c
@@ -283,10 +283,10 @@ LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
 
 
 LUALIB_API int luaL_execresult (lua_State *L, int stat) {
-  const char *what = "exit";  /* type of termination */
   if (stat != 0 && errno != 0)  /* error with an 'errno'? */
     return luaL_fileresult(L, 0, NULL);
   else {
+    const char *what = "exit";  /* type of termination */
     l_inspectstat(stat, what);  /* interpret result */
     if (*what == 'e' && stat == 0)  /* successful termination? */
       lua_pushboolean(L, 1);
@@ -639,10 +639,14 @@ 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 +654,16 @@ 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 +679,7 @@ 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 */
@@ -1006,43 +1018,67 @@ static int panic (lua_State *L) {
 
 
 /*
-** Emit a warning. '*warnstate' means:
-** 0 - warning system is off;
-** 1 - ready to start a new message;
-** 2 - previous message is to be continued.
+** Warning functions:
+** warnfoff: warning system is off
+** warnfon: ready to start a new message
+** warnfcont: previous message is to be continued
 */
-static void warnf (void *ud, const char *message, int tocont) {
-  int *warnstate = (int *)ud;
-  if (*warnstate != 2 && !tocont && *message == '@') {  /* control message? */
-    if (strcmp(message, "@off") == 0)
-      *warnstate = 0;
-    else if (strcmp(message, "@on") == 0)
-      *warnstate = 1;
-    return;
+static void warnfoff (void *ud, const char *message, int tocont);
+static void warnfon (void *ud, const char *message, int tocont);
+static void warnfcont (void *ud, const char *message, int tocont);
+
+
+/*
+** Check whether message is a control message. If so, execute the
+** control or ignore it if unknown.
+*/
+static int checkcontrol (lua_State *L, const char *message, int tocont) {
+  if (tocont || *(message++) != '@')  /* not a control message? */
+    return 0;
+  else {
+    if (strcmp(message, "off") == 0)
+      lua_setwarnf(L, warnfoff, L);  /* turn warnings off */
+    else if (strcmp(message, "on") == 0)
+      lua_setwarnf(L, warnfon, L);   /* turn warnings on */
+    return 1;  /* it was a control message */
   }
-  else if (*warnstate == 0)  /* warnings off? */
-    return;
-  if (*warnstate == 1)  /* previous message was the last? */
-    lua_writestringerror("%s", "Lua warning: ");  /* start a new warning */
+}
+
+
+static void warnfoff (void *ud, const char *message, int tocont) {
+  checkcontrol((lua_State *)ud, message, tocont);
+}
+
+
+/*
+** Writes the message and handle 'tocont', finishing the message
+** if needed and setting the next warn function.
+*/
+static void warnfcont (void *ud, const char *message, int tocont) {
+  lua_State *L = (lua_State *)ud;
   lua_writestringerror("%s", message);  /* write message */
   if (tocont)  /* not the last part? */
-    *warnstate = 2;  /* to be continued */
+    lua_setwarnf(L, warnfcont, L);  /* to be continued */
   else {  /* last part */
     lua_writestringerror("%s", "\n");  /* finish message with end-of-line */
-    *warnstate = 1;  /* ready to start a new message */
+    lua_setwarnf(L, warnfon, L);  /* next call is a new message */
   }
 }
 
 
+static void warnfon (void *ud, const char *message, int tocont) {
+  if (checkcontrol((lua_State *)ud, message, tocont))  /* control message? */
+    return;  /* nothing else to be done */
+  lua_writestringerror("%s", "Lua warning: ");  /* start a new warning */
+  warnfcont(ud, message, tocont);  /* finish processing */
+}
+
+
 LUALIB_API lua_State *luaL_newstate (void) {
   lua_State *L = lua_newstate(l_alloc, NULL);
   if (L) {
-    int *warnstate;  /* space for warning state */
     lua_atpanic(L, &panic);
-    warnstate = (int *)lua_newuserdatauv(L, sizeof(int), 0);
-    luaL_ref(L, LUA_REGISTRYINDEX);  /* make sure it won't be collected */
-    *warnstate = 0;  /* default is warnings off */
-    lua_setwarnf(L, warnf, warnstate);
+    lua_setwarnf(L, warnfoff, L);  /* default is warnings off */
   }
   return L;
 }
diff --git a/src/lua/lauxlib.h b/src/lua/lauxlib.h
index 59fef6a..6571491 100644
--- a/src/lua/lauxlib.h
+++ b/src/lua/lauxlib.h
@@ -158,6 +158,22 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
 
 
 /*
+** 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/src/lua/lcode.c b/src/lua/lcode.c
index 6f241c9..d8d353f 100644
--- a/src/lua/lcode.c
+++ b/src/lua/lcode.c
@@ -545,11 +545,14 @@ 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 +566,8 @@ 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);
@@ -753,7 +757,7 @@ void luaK_setoneret (FuncState *fs, expdesc *e) {
 
 
 /*
-** Ensure that expression 'e' is not a variable (nor a constant).
+** Ensure that expression 'e' is not a variable (nor a <const>).
 ** (Expression still may have jump lists.)
 */
 void luaK_dischargevars (FuncState *fs, expdesc *e) {
@@ -763,7 +767,7 @@ 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;
     }
@@ -805,8 +809,8 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
 
 
 /*
-** Ensures expression value is in register 'reg' (and therefore
-** 'e' will become a non-relocatable expression).
+** Ensure expression value is in register 'reg', making 'e' a
+** non-relocatable expression.
 ** (Expression still may have jump lists.)
 */
 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
@@ -860,7 +864,8 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
 
 
 /*
-** Ensures expression value is in any register.
+** Ensure expression value is in a register, making 'e' a
+** non-relocatable expression.
 ** (Expression still may have jump lists.)
 */
 static void discharge2anyreg (FuncState *fs, expdesc *e) {
@@ -946,8 +951,11 @@ int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
       exp2reg(fs, e, e->u.info);  /* put final result in it */
       return e->u.info;
     }
+    /* else expression has jumps and cannot change its register
+       to hold the jump values, because it is a local variable.
+       Go through to the default case. */
   }
-  luaK_exp2nextreg(fs, e);  /* otherwise, use next available register */
+  luaK_exp2nextreg(fs, e);  /* default: use next available register */
   return e->u.info;
 }
 
@@ -1032,7 +1040,7 @@ 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: {
@@ -1272,7 +1280,7 @@ 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;
diff --git a/src/lua/ldblib.c b/src/lua/ldblib.c
index 5a326ad..15593bf 100644
--- a/src/lua/ldblib.c
+++ b/src/lua/ldblib.c
@@ -377,7 +377,7 @@ 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 +420,7 @@ 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/src/lua/ldo.c b/src/lua/ldo.c
index 5729b19..4b55c31 100644
--- a/src/lua/ldo.c
+++ b/src/lua/ldo.c
@@ -192,7 +192,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
     else return 0;  /* do not raise an error */
   }
   for (; lim < newsize; lim++)
-    setnilvalue(s2v(newstack + lim)); /* erase new segment */
+    setnilvalue(s2v(newstack + lim + EXTRA_STACK)); /* erase new segment */
   correctstack(L, L->stack, newstack);
   L->stack = newstack;
   L->stack_last = L->stack + newsize;
@@ -534,11 +534,11 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
 
 
 /*
-** Call a function (C or Lua). 'inc' can be 1 (increment number
-** of recursive invocations in the C stack) or nyci (the same plus
-** increment number of non-yieldable calls).
+** Call a function (C or Lua) through C. 'inc' can be 1 (increment
+** number of recursive invocations in the C stack) or nyci (the same
+** plus increment number of non-yieldable calls).
 */
-static void docall (lua_State *L, StkId func, int nResults, int inc) {
+static void ccall (lua_State *L, StkId func, int nResults, int inc) {
   CallInfo *ci;
   L->nCcalls += inc;
   if (unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
@@ -552,10 +552,10 @@ static void docall (lua_State *L, StkId func, int nResults, int inc) {
 
 
 /*
-** External interface for 'docall'
+** External interface for 'ccall'
 */
 void luaD_call (lua_State *L, StkId func, int nResults) {
-  return docall(L, func, nResults, 1);
+  ccall(L, func, nResults, 1);
 }
 
 
@@ -563,7 +563,7 @@ void luaD_call (lua_State *L, StkId func, int nResults) {
 ** Similar to 'luaD_call', but does not allow yields during the call.
 */
 void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
-  return docall(L, func, nResults, nyci);
+  ccall(L, func, nResults, nyci);
 }
 
 
@@ -678,7 +678,7 @@ 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? */
-    docall(L, firstArg - 1, LUA_MULTRET, 1);  /* just call its body */
+    ccall(L, firstArg - 1, LUA_MULTRET, 1);  /* 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) */
diff --git a/src/lua/lgc.c b/src/lua/lgc.c
index 5dba56f..bab9beb 100644
--- a/src/lua/lgc.c
+++ b/src/lua/lgc.c
@@ -632,8 +632,8 @@ static int traversethread (global_State *g, lua_State *th) {
   for (uv = th->openupval; uv != NULL; uv = uv->u.open.next)
     markobject(g, uv);  /* open upvalues cannot be collected */
   if (g->gcstate == GCSatomic) {  /* final traversal? */
-    for (; o < th->stack_last; o++)  /* clear not-marked stack slice */
-      setnilvalue(s2v(o));
+    for (; o < th->stack_last + EXTRA_STACK; o++)
+      setnilvalue(s2v(o));  /* clear dead stack slice */
     /* 'remarkupvals' may have removed thread from 'twups' list */
     if (!isintwups(th) && th->openupval != NULL) {
       th->twups = g->twups;  /* link it back to the list */
diff --git a/src/lua/liolib.c b/src/lua/liolib.c
index 60ab1bf..7951672 100644
--- a/src/lua/liolib.c
+++ b/src/lua/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
+
 /* }====================================================== */
 
 
diff --git a/src/lua/llex.c b/src/lua/llex.c
index 3d6b2b9..e991517 100644
--- a/src/lua/llex.c
+++ b/src/lua/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;
 }
 
@@ -254,9 +257,10 @@ static int read_numeral (LexState *ls, SemInfo *seminfo) {
 
 
 /*
-** reads a sequence '[=*[' or ']=*]', leaving the last bracket.
-** If sequence is well formed, return its number of '='s + 2; otherwise,
-** return 1 if there is no '='s or 0 otherwise (an unfinished '[==...').
+** read a sequence '[=*[' or ']=*]', leaving the last bracket. If
+** sequence is well formed, return its number of '='s + 2; otherwise,
+** return 1 if it is a single bracket (no '='s and no 2nd bracket);
+** otherwise (an unfinished '[==...') return 0.
 */
 static size_t skip_sep (LexState *ls) {
   size_t count = 0;
@@ -481,34 +485,34 @@ static int llex (LexState *ls, SemInfo *seminfo) {
       }
       case '=': {
         next(ls);
-        if (check_next1(ls, '=')) return TK_EQ;
+        if (check_next1(ls, '=')) return TK_EQ;  /* '==' */
         else return '=';
       }
       case '<': {
         next(ls);
-        if (check_next1(ls, '=')) return TK_LE;
-        else if (check_next1(ls, '<')) return TK_SHL;
+        if (check_next1(ls, '=')) return TK_LE;  /* '<=' */
+        else if (check_next1(ls, '<')) return TK_SHL;  /* '<<' */
         else return '<';
       }
       case '>': {
         next(ls);
-        if (check_next1(ls, '=')) return TK_GE;
-        else if (check_next1(ls, '>')) return TK_SHR;
+        if (check_next1(ls, '=')) return TK_GE;  /* '>=' */
+        else if (check_next1(ls, '>')) return TK_SHR;  /* '>>' */
         else return '>';
       }
       case '/': {
         next(ls);
-        if (check_next1(ls, '/')) return TK_IDIV;
+        if (check_next1(ls, '/')) return TK_IDIV;  /* '//' */
         else return '/';
       }
       case '~': {
         next(ls);
-        if (check_next1(ls, '=')) return TK_NE;
+        if (check_next1(ls, '=')) return TK_NE;  /* '~=' */
         else return '~';
       }
       case ':': {
         next(ls);
-        if (check_next1(ls, ':')) return TK_DBCOLON;
+        if (check_next1(ls, ':')) return TK_DBCOLON;  /* '::' */
         else return ':';
       }
       case '"': case '\'': {  /* short literal strings */
@@ -547,7 +551,7 @@ static int llex (LexState *ls, SemInfo *seminfo) {
             return TK_NAME;
           }
         }
-        else {  /* single-char tokens (+ - / ...) */
+        else {  /* single-char tokens ('+', '*', '%', '{', '}', ...) */
           int c = ls->current;
           next(ls);
           return c;
diff --git a/src/lua/llimits.h b/src/lua/llimits.h
index a76c13e..d039483 100644
--- a/src/lua/llimits.h
+++ b/src/lua/llimits.h
@@ -326,7 +326,8 @@ typedef l_uint32 Instruction;
 
 /* exponentiation */
 #if !defined(luai_numpow)
-#define luai_numpow(L,a,b)      ((void)L, l_mathop(pow)(a,b))
+#define luai_numpow(L,a,b)  \
+  ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b))
 #endif
 
 /* the others are quite standard operations */
diff --git a/src/lua/lobject.c b/src/lua/lobject.c
index f8ea917..0e504be 100644
--- a/src/lua/lobject.c
+++ b/src/lua/lobject.c
@@ -258,7 +258,7 @@ static const char *l_str2d (const char *s, lua_Number *result) {
   if (endptr == NULL) {  /* failed? may be a different locale */
     char buff[L_MAXLENNUM + 1];
     const char *pdot = strchr(s, '.');
-    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
+    if (pdot == NULL || strlen(s) > L_MAXLENNUM)
       return NULL;  /* string too long or no dot; fail */
     strcpy(buff, s);  /* copy string to buffer */
     buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
diff --git a/src/lua/lparser.c b/src/lua/lparser.c
index bcdcfb6..249ba9a 100644
--- a/src/lua/lparser.c
+++ b/src/lua/lparser.c
@@ -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));
   }
@@ -620,7 +620,7 @@ 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 +661,7 @@ 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)
@@ -945,7 +945,7 @@ static void setvararg (FuncState *fs, int nparams) {
 
 
 static void parlist (LexState *ls) {
-  /* parlist -> [ param { ',' param } ] */
+  /* parlist -> [ {NAME ','} (NAME | '...') ] */
   FuncState *fs = ls->fs;
   Proto *f = fs->f;
   int nparams = 0;
@@ -953,12 +953,12 @@ static void parlist (LexState *ls) {
   if (ls->t.token != ')') {  /* is 'parlist' not empty? */
     do {
       switch (ls->t.token) {
-        case TK_NAME: {  /* param -> NAME */
+        case TK_NAME: {
           new_localvar(ls, str_checkname(ls));
           nparams++;
           break;
         }
-        case TK_DOTS: {  /* param -> '...' */
+        case TK_DOTS: {
           luaX_next(ls);
           isvararg = 1;
           break;
@@ -1330,13 +1330,13 @@ 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 +1346,7 @@ 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 +1411,7 @@ 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 */
@@ -1488,7 +1488,7 @@ 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 */
   }
@@ -1623,59 +1623,21 @@ static void forstat (LexState *ls, int line) {
 }
 
 
-/*
-** Check whether next instruction is a single jump (a 'break', a 'goto'
-** to a forward label, or a 'goto' to a backward label with no variable
-** to close). If so, set the name of the 'label' it is jumping to
-** ("break" for a 'break') or to where it is jumping to ('target') and
-** return true. If not a single jump, leave input unchanged, to be
-** handled as a regular statement.
-*/
-static int issinglejump (LexState *ls, TString **label, int *target) {
-  if (testnext(ls, TK_BREAK)) {  /* a break? */
-    *label = luaS_newliteral(ls->L, "break");
-    return 1;
-  }
-  else if (ls->t.token != TK_GOTO || luaX_lookahead(ls) != TK_NAME)
-    return 0;  /* not a valid goto */
-  else {
-    TString *lname = ls->lookahead.seminfo.ts;  /* label's id */
-    Labeldesc *lb = findlabel(ls, lname);
-    if (lb) {  /* a backward jump? */
-      /* does it need to close variables? */
-      if (luaY_nvarstack(ls->fs) > stacklevel(ls->fs, lb->nactvar))
-        return 0;  /* not a single jump; cannot optimize */
-      *target = lb->pc;
-    }
-    else  /* jump forward */
-      *label = lname;
-    luaX_next(ls);  /* skip goto */
-    luaX_next(ls);  /* skip name */
-    return 1;
-  }
-}
-
-
 static void test_then_block (LexState *ls, int *escapelist) {
   /* test_then_block -> [IF | ELSEIF] cond THEN block */
   BlockCnt bl;
-  int line;
   FuncState *fs = ls->fs;
-  TString *jlb = NULL;
-  int target = NO_JUMP;
   expdesc v;
   int jf;  /* instruction to skip 'then' code (if condition is false) */
   luaX_next(ls);  /* skip IF or ELSEIF */
   expr(ls, &v);  /* read condition */
   checknext(ls, TK_THEN);
-  line = ls->linenumber;
-  if (issinglejump(ls, &jlb, &target)) {  /* 'if x then goto' ? */
-    luaK_goiffalse(ls->fs, &v);  /* will jump to label if condition is true */
+  if (ls->t.token == TK_BREAK) {  /* 'if x then break' ? */
+    int line = ls->linenumber;
+    luaK_goiffalse(ls->fs, &v);  /* will jump if condition is true */
+    luaX_next(ls);  /* skip 'break' */
     enterblock(fs, &bl, 0);  /* must enter block before 'goto' */
-    if (jlb != NULL)  /* forward jump? */
-      newgotoentry(ls, jlb, line, v.t);  /* will be resolved later */
-    else  /* backward jump */
-      luaK_patchlist(fs, v.t, target);  /* jump directly to 'target' */
+    newgotoentry(ls, luaS_newliteral(ls->L, "break"), line, v.t);
     while (testnext(ls, ';')) {}  /* skip semicolons */
     if (block_follow(ls, 0)) {  /* jump is the entire block? */
       leaveblock(fs);
@@ -1684,7 +1646,7 @@ static void test_then_block (LexState *ls, int *escapelist) {
     else  /* must skip over 'then' part if condition is false */
       jf = luaK_jump(fs);
   }
-  else {  /* regular case (not a jump) */
+  else {  /* regular case (not a break) */
     luaK_goiftrue(ls->fs, &v);  /* skip over block if condition is false */
     enterblock(fs, &bl, 0);
     jf = v.f;
@@ -1746,13 +1708,13 @@ static void checktoclose (LexState *ls, int level) {
     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);
+    luaK_codeABC(fs, OP_TBC, reglevel(fs, level), 0, 0);
   }
 }
 
 
 static void localstat (LexState *ls) {
-  /* stat -> LOCAL ATTRIB NAME {',' ATTRIB NAME} ['=' explist] */
+  /* stat -> LOCAL NAME ATTRIB { ',' NAME ATTRIB } ['=' explist] */
   FuncState *fs = ls->fs;
   int toclose = -1;  /* index of to-be-closed variable (if any) */
   Vardesc *var;  /* last variable */
diff --git a/src/lua/lparser.h b/src/lua/lparser.h
index 618cb01..5e4500f 100644
--- a/src/lua/lparser.h
+++ b/src/lua/lparser.h
@@ -23,7 +23,7 @@
 
 /* kinds of variables/expressions */
 typedef enum {
-  VVOID,  /* when 'expdesc' describes the last expression a list,
+  VVOID,  /* when 'expdesc' describes the last expression of a list,
              this kind means an empty list (so, no expression) */
   VNIL,  /* constant nil */
   VTRUE,  /* constant true */
@@ -35,10 +35,11 @@ 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 constant; info = absolute index in 'actvar.arr'  */
+  VCONST,  /* compile-time <const> variable;
+              info = absolute index in 'actvar.arr'  */
   VINDEXED,  /* indexed variable;
                 ind.t = table register;
                 ind.idx = key's R index */
@@ -76,7 +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;
@@ -96,7 +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/src/lua/lstate.c b/src/lua/lstate.c
index 4227429..1596b51 100644
--- a/src/lua/lstate.c
+++ b/src/lua/lstate.c
@@ -181,7 +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);
-  for (i = 0; i < BASIC_STACK_SIZE; i++)
+  for (i = 0; i < BASIC_STACK_SIZE + EXTRA_STACK; i++)
     setnilvalue(s2v(L1->stack + i));  /* erase new stack */
   L1->top = L1->stack;
   L1->stack_last = L1->stack + BASIC_STACK_SIZE;
@@ -213,17 +213,14 @@ 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));
 }
 
 
diff --git a/src/lua/ltable.c b/src/lua/ltable.c
index 38bee1d..e9410f9 100644
--- a/src/lua/ltable.c
+++ b/src/lua/ltable.c
@@ -166,17 +166,24 @@ static Node *mainpositionTV (const Table *t, const TValue *key) {
 
 
 /*
-** Check whether key 'k1' is equal to the key in node 'n2'.
-** This equality is raw, so there are no metamethods. Floats
-** with integer values have been normalized, so integers cannot
-** be equal to floats. It is assumed that 'eqshrstr' is simply
-** pointer equality, so that short strings are handled in the
-** default case.
+** Check whether key 'k1' is equal to the key in node 'n2'. This
+** equality is raw, so there are no metamethods. Floats with integer
+** values have been normalized, so integers cannot be equal to
+** floats. It is assumed that 'eqshrstr' is simply pointer equality, so
+** that short strings are handled in the default case.
 ** A true 'deadok' means to accept dead keys as equal to their original
-** values, which can only happen if the original key was collectable.
-** All dead values are compared in the default case, by pointer
-** identity.  (Note that dead long strings are also compared by
-** identity).
+** values. All dead keys are compared in the default case, by pointer
+** identity. (Only collectable objects can produce dead keys.) Note that
+** dead long strings are also compared by identity.
+** Once a key is dead, its corresponding value may be collected, and
+** then another value can be created with the same address. If this
+** other value is given to 'next', 'equalkey' will signal a false
+** positive. In a regular traversal, this situation should never happen,
+** as all keys given to 'next' came from the table itself, and therefore
+** could not have been collected. Outside a regular traversal, we
+** have garbage in, garbage out. What is relevant is that this false
+** positive does not break anything.  (In particular, 'next' will return
+** some other valid item on the table or nil.)
 */
 static int equalkey (const TValue *k1, const Node *n2, int deadok) {
   if ((rawtt(k1) != keytt(n2)) &&  /* not the same variants? */
@@ -478,7 +485,7 @@ 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));
     }
   }
 }
@@ -625,7 +632,7 @@ 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)))
@@ -647,7 +654,8 @@ 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));
@@ -675,7 +683,7 @@ 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);
 }
 
 
@@ -763,28 +771,39 @@ 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/src/lua/ltable.h b/src/lua/ltable.h
index c0060f4..7bbbcb2 100644
--- a/src/lua/ltable.h
+++ b/src/lua/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/src/lua/lualib.h b/src/lua/lualib.h
index eb08b53..2625529 100644
--- a/src/lua/lualib.h
+++ b/src/lua/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/src/lua/lvm.c b/src/lua/lvm.c
index aa3b22b..ccebdbe 100644
--- a/src/lua/lvm.c
+++ b/src/lua/lvm.c
@@ -337,10 +337,7 @@ 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;