Fixed issue #174.

13 files changed, 91 insertions, 65 deletions

diff --git a/src/3rdParty/lua/lauxlib.c b/src/3rdParty/lua/lauxlib.c
index 4ca6c65..923105e 100644
--- a/src/3rdParty/lua/lauxlib.c
+++ b/src/3rdParty/lua/lauxlib.c
@@ -80,6 +80,7 @@ static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
   int top = lua_gettop(L);
   lua_getinfo(L, "f", ar);  /* push function */
   lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
+  luaL_checkstack(L, 6, "not enough stack");  /* slots for 'findfield' */
   if (findfield(L, top + 1, 2)) {
     const char *name = lua_tostring(L, -1);
     if (strncmp(name, LUA_GNAME ".", 3) == 0) {  /* name start with '_G.'? */
@@ -249,11 +250,13 @@ LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
     return 1;
   }
   else {
+    const char *msg;
     luaL_pushfail(L);
+    msg = (en != 0) ? strerror(en) : "(no extra info)";
     if (fname)
-      lua_pushfstring(L, "%s: %s", fname, strerror(en));
+      lua_pushfstring(L, "%s: %s", fname, msg);
     else
-      lua_pushstring(L, strerror(en));
+      lua_pushstring(L, msg);
     lua_pushinteger(L, en);
     return 3;
   }
@@ -732,9 +735,12 @@ static const char *getF (lua_State *L, void *ud, size_t *size) {
 
 
 static int errfile (lua_State *L, const char *what, int fnameindex) {
-  const char *serr = strerror(errno);
+  int err = errno;
   const char *filename = lua_tostring(L, fnameindex) + 1;
-  lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
+  if (err != 0)
+    lua_pushfstring(L, "cannot %s %s: %s", what, filename, strerror(err));
+  else
+    lua_pushfstring(L, "cannot %s %s", what, filename);
   lua_remove(L, fnameindex);
   return LUA_ERRFILE;
 }
@@ -787,6 +793,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   }
   else {
     lua_pushfstring(L, "@%s", filename);
+    errno = 0;
     lf.f = fopen(filename, "r");
     if (lf.f == NULL) return errfile(L, "open", fnameindex);
   }
@@ -796,6 +803,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   if (c == LUA_SIGNATURE[0]) {  /* binary file? */
     lf.n = 0;  /* remove possible newline */
     if (filename) {  /* "real" file? */
+      errno = 0;
       lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
       if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
       skipcomment(lf.f, &c);  /* re-read initial portion */
@@ -803,6 +811,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
   }
   if (c != EOF)
     lf.buff[lf.n++] = c;  /* 'c' is the first character of the stream */
+  errno = 0;
   status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
   readstatus = ferror(lf.f);
   if (filename) fclose(lf.f);  /* close file (even in case of errors) */
@@ -933,7 +942,7 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
   luaL_checkstack(L, nup, "too many upvalues");
   for (; l->name != NULL; l++) {  /* fill the table with given functions */
-    if (l->func == NULL)  /* place holder? */
+    if (l->func == NULL)  /* placeholder? */
       lua_pushboolean(L, 0);
     else {
       int i;
@@ -1025,9 +1034,14 @@ static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
 }
 
 
+/*
+** Standard panic funcion just prints an error message. The test
+** with 'lua_type' avoids possible memory errors in 'lua_tostring'.
+*/
 static int panic (lua_State *L) {
-  const char *msg = lua_tostring(L, -1);
-  if (msg == NULL) msg = "error object is not a string";
+  const char *msg = (lua_type(L, -1) == LUA_TSTRING)
+                  ? lua_tostring(L, -1)
+                  : "error object is not a string";
   lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
                         msg);
   return 0;  /* return to Lua to abort */
diff --git a/src/3rdParty/lua/lcode.c b/src/3rdParty/lua/lcode.c
index caac6ba..8761614 100644
--- a/src/3rdParty/lua/lcode.c
+++ b/src/3rdParty/lua/lcode.c
@@ -776,7 +776,8 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
       break;
     }
     case VLOCAL: {  /* already in a register */
-      e->u.info = e->u.var.ridx;
+      int temp = e->u.var.ridx;
+      e->u.info = temp;  /* (can't do a direct assignment; values overlap) */
       e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
@@ -1283,8 +1284,9 @@ void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
   if (t->k == VUPVAL && !isKstr(fs, k))  /* upvalue indexed by non 'Kstr'? */
     luaK_exp2anyreg(fs, t);  /* put it in a register */
   if (t->k == VUPVAL) {
+    int temp = t->u.info;  /* upvalue index */
     lua_assert(isKstr(fs, k));
-    t->u.ind.t = t->u.info;  /* upvalue index */
+    t->u.ind.t = temp;  /* (can't do a direct assignment; values overlap) */
     t->u.ind.idx = k->u.info;  /* literal short string */
     t->k = VINDEXUP;
   }
diff --git a/src/3rdParty/lua/ldebug.c b/src/3rdParty/lua/ldebug.c
index b1f16ac..591b352 100644
--- a/src/3rdParty/lua/ldebug.c
+++ b/src/3rdParty/lua/ldebug.c
@@ -31,7 +31,7 @@
 
 
 
-#define noLuaClosure(f)         ((f) == NULL || (f)->c.tt == LUA_VCCL)
+#define LuaClosure(f)           ((f) != NULL && (f)->c.tt == LUA_VLCL)
 
 
 static const char *funcnamefromcall (lua_State *L, CallInfo *ci,
@@ -254,7 +254,7 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
 
 
 static void funcinfo (lua_Debug *ar, Closure *cl) {
-  if (noLuaClosure(cl)) {
+  if (!LuaClosure(cl)) {
     ar->source = "=[C]";
     ar->srclen = LL("=[C]");
     ar->linedefined = -1;
@@ -288,29 +288,31 @@ static int nextline (const Proto *p, int currentline, int pc) {
 
 
 static void collectvalidlines (lua_State *L, Closure *f) {
-  if (noLuaClosure(f)) {
+  if (!LuaClosure(f)) {
     setnilvalue(s2v(L->top.p));
     api_incr_top(L);
   }
   else {
-    int i;
-    TValue v;
     const Proto *p = f->l.p;
     int currentline = p->linedefined;
     Table *t = luaH_new(L);  /* new table to store active lines */
     sethvalue2s(L, L->top.p, t);  /* push it on stack */
     api_incr_top(L);
-    setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
-    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 */
+    if (p->lineinfo != NULL) {  /* proto with debug information? */
+      int i;
+      TValue v;
+      setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
+      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 */
+      }
     }
   }
 }
@@ -339,7 +341,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
       }
       case 'u': {
         ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
-        if (noLuaClosure(f)) {
+        if (!LuaClosure(f)) {
           ar->isvararg = 1;
           ar->nparams = 0;
         }
@@ -925,12 +927,12 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) {
   }
   pc++;  /* reference is always next instruction */
   ci->u.l.savedpc = pc;  /* save 'pc' */
-  counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
+  counthook = (mask & LUA_MASKCOUNT) && (--L->hookcount == 0);
   if (counthook)
     resethookcount(L);  /* reset count */
   else if (!(mask & LUA_MASKLINE))
     return 1;  /* no line hook and count != 0; nothing to be done now */
-  if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
+  if (ci->callstatus & CIST_HOOKYIELD) {  /* hook yielded last time? */
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
     return 1;  /* do not call hook again (VM yielded, so it did not move) */
   }
@@ -952,7 +954,6 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) {
   if (L->status == LUA_YIELD) {  /* did hook yield? */
     if (counthook)
       L->hookcount = 1;  /* undo decrement to zero */
-    ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
     ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
     luaD_throw(L, LUA_YIELD);
   }
diff --git a/src/3rdParty/lua/ldo.c b/src/3rdParty/lua/ldo.c
index bd8d965..ea05295 100644
--- a/src/3rdParty/lua/ldo.c
+++ b/src/3rdParty/lua/ldo.c
@@ -792,6 +792,10 @@ static void resume (lua_State *L, void *ud) {
     lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
     if (isLua(ci)) {  /* yielded inside a hook? */
+      /* undo increment made by 'luaG_traceexec': instruction was not
+         executed yet */
+      lua_assert(ci->callstatus & CIST_HOOKYIELD);
+      ci->u.l.savedpc--;
       L->top.p = firstArg;  /* discard arguments */
       luaV_execute(L, ci);  /* just continue running Lua code */
     }
diff --git a/src/3rdParty/lua/lgc.c b/src/3rdParty/lua/lgc.c
index 253a289..5817f9e 100644
--- a/src/3rdParty/lua/lgc.c
+++ b/src/3rdParty/lua/lgc.c
@@ -1713,7 +1713,7 @@ static void fullinc (lua_State *L, global_State *g) {
   /* finish any pending sweep phase to start a new cycle */
   luaC_runtilstate(L, bitmask(GCSpause));
   luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
-  g->gcstate = GCSenteratomic;  /* go straight to atomic phase ??? */
+  g->gcstate = GCSenteratomic;  /* go straight to atomic phase */
   luaC_runtilstate(L, bitmask(GCScallfin));  /* run up to finalizers */
   /* estimate must be correct after a full GC cycle */
   lua_assert(g->GCestimate == gettotalbytes(g));
diff --git a/src/3rdParty/lua/liolib.c b/src/3rdParty/lua/liolib.c
index b08397d..c5075f3 100644
--- a/src/3rdParty/lua/liolib.c
+++ b/src/3rdParty/lua/liolib.c
@@ -245,8 +245,8 @@ static int f_gc (lua_State *L) {
 */
 static int io_fclose (lua_State *L) {
   LStream *p = tolstream(L);
-  int res = fclose(p->f);
-  return luaL_fileresult(L, (res == 0), NULL);
+  errno = 0;
+  return luaL_fileresult(L, (fclose(p->f) == 0), NULL);
 }
 
 
@@ -272,6 +272,7 @@ static int io_open (lua_State *L) {
   LStream *p = newfile(L);
   const char *md = mode;  /* to traverse/check mode */
   luaL_argcheck(L, l_checkmode(md), 2, "invalid mode");
+  errno = 0;
   p->f = fopen(filename, mode);
   return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
 }
@@ -292,6 +293,7 @@ static int io_popen (lua_State *L) {
   const char *mode = luaL_optstring(L, 2, "r");
   LStream *p = newprefile(L);
   luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
+  errno = 0;
   p->f = l_popen(L, filename, mode);
   p->closef = &io_pclose;
   return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
@@ -300,6 +302,7 @@ static int io_popen (lua_State *L) {
 
 static int io_tmpfile (lua_State *L) {
   LStream *p = newfile(L);
+  errno = 0;
   p->f = tmpfile();
   return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
 }
@@ -567,6 +570,7 @@ static int g_read (lua_State *L, FILE *f, int first) {
   int nargs = lua_gettop(L) - 1;
   int n, success;
   clearerr(f);
+  errno = 0;
   if (nargs == 0) {  /* no arguments? */
     success = read_line(L, f, 1);
     n = first + 1;  /* to return 1 result */
@@ -660,6 +664,7 @@ static int io_readline (lua_State *L) {
 static int g_write (lua_State *L, FILE *f, int arg) {
   int nargs = lua_gettop(L) - arg;
   int status = 1;
+  errno = 0;
   for (; nargs--; arg++) {
     if (lua_type(L, arg) == LUA_TNUMBER) {
       /* optimization: could be done exactly as for strings */
@@ -678,7 +683,8 @@ static int g_write (lua_State *L, FILE *f, int arg) {
   }
   if (l_likely(status))
     return 1;  /* file handle already on stack top */
-  else return luaL_fileresult(L, status, NULL);
+  else
+    return luaL_fileresult(L, status, NULL);
 }
 
 
@@ -703,6 +709,7 @@ static int f_seek (lua_State *L) {
   l_seeknum offset = (l_seeknum)p3;
   luaL_argcheck(L, (lua_Integer)offset == p3, 3,
                   "not an integer in proper range");
+  errno = 0;
   op = l_fseek(f, offset, mode[op]);
   if (l_unlikely(op))
     return luaL_fileresult(L, 0, NULL);  /* error */
@@ -719,19 +726,25 @@ static int f_setvbuf (lua_State *L) {
   FILE *f = tofile(L);
   int op = luaL_checkoption(L, 2, NULL, modenames);
   lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
-  int res = setvbuf(f, NULL, mode[op], (size_t)sz);
+  int res;
+  errno = 0;
+  res = setvbuf(f, NULL, mode[op], (size_t)sz);
   return luaL_fileresult(L, res == 0, NULL);
 }
 
 
 
 static int io_flush (lua_State *L) {
-  return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
+  FILE *f = getiofile(L, IO_OUTPUT);
+  errno = 0;
+  return luaL_fileresult(L, fflush(f) == 0, NULL);
 }
 
 
 static int f_flush (lua_State *L) {
-  return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
+  FILE *f = tofile(L);
+  errno = 0;
+  return luaL_fileresult(L, fflush(f) == 0, NULL);
 }
 
 
@@ -773,7 +786,7 @@ static const luaL_Reg meth[] = {
 ** metamethods for file handles
 */
 static const luaL_Reg metameth[] = {
-  {"__index", NULL},  /* place holder */
+  {"__index", NULL},  /* placeholder */
   {"__gc", f_gc},
   {"__close", f_gc},
   {"__tostring", f_tostring},
diff --git a/src/3rdParty/lua/lmathlib.c b/src/3rdParty/lua/lmathlib.c
index f140d62..4381063 100644
--- a/src/3rdParty/lua/lmathlib.c
+++ b/src/3rdParty/lua/lmathlib.c
@@ -352,7 +352,7 @@ static lua_Number I2d (Rand64 x) {
   SRand64 sx = (SRand64)(trim64(x) >> shift64_FIG);
   lua_Number res = (lua_Number)(sx) * scaleFIG;
   if (sx < 0)
-    res += 1.0;  /* correct the two's complement if negative */
+    res += l_mathop(1.0);  /* correct the two's complement if negative */
   lua_assert(0 <= res && res < 1);
   return res;
 }
diff --git a/src/3rdParty/lua/loslib.c b/src/3rdParty/lua/loslib.c
index ad5a927..ba80d72 100644
--- a/src/3rdParty/lua/loslib.c
+++ b/src/3rdParty/lua/loslib.c
@@ -155,6 +155,7 @@ static int os_execute (lua_State *L) {
 
 static int os_remove (lua_State *L) {
   const char *filename = luaL_checkstring(L, 1);
+  errno = 0;
   return luaL_fileresult(L, remove(filename) == 0, filename);
 }
 
@@ -162,6 +163,7 @@ static int os_remove (lua_State *L) {
 static int os_rename (lua_State *L) {
   const char *fromname = luaL_checkstring(L, 1);
   const char *toname = luaL_checkstring(L, 2);
+  errno = 0;
   return luaL_fileresult(L, rename(fromname, toname) == 0, NULL);
 }
 
diff --git a/src/3rdParty/lua/lstring.c b/src/3rdParty/lua/lstring.c
index e921dd0..9775735 100644
--- a/src/3rdParty/lua/lstring.c
+++ b/src/3rdParty/lua/lstring.c
@@ -224,7 +224,7 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
     return internshrstr(L, str, l);
   else {
     TString *ts;
-    if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
+    if (l_unlikely(l * sizeof(char) >= (MAX_SIZE - sizeof(TString))))
       luaM_toobig(L);
     ts = luaS_createlngstrobj(L, l);
     memcpy(getlngstr(ts), str, l * sizeof(char));
diff --git a/src/3rdParty/lua/lua.h b/src/3rdParty/lua/lua.h
index 040cc8e..f050dac 100644
--- a/src/3rdParty/lua/lua.h
+++ b/src/3rdParty/lua/lua.h
@@ -1,7 +1,7 @@
 /*
 ** $Id: lua.h $
 ** Lua - A Scripting Language
-** Lua.org, PUC-Rio, Brazil (www.lua.org)
+** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
 */
 
@@ -13,19 +13,20 @@
 #include <stddef.h>
 
 
-#define LUA_COPYRIGHT   LUA_RELEASE "  Copyright (C) 1994-2023 Lua.org, PUC-Rio"
-#define LUA_AUTHORS     "R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
-
+#include "luaconf.h"
 
-#define LUA_VERSION_MAJOR_N     5
-#define LUA_VERSION_MINOR_N     4
-#define LUA_VERSION_RELEASE_N   6
 
-#define LUA_VERSION_NUM  (LUA_VERSION_MAJOR_N * 100 + LUA_VERSION_MINOR_N)
-#define LUA_VERSION_RELEASE_NUM  (LUA_VERSION_NUM * 100 + LUA_VERSION_RELEASE_N)
+#define LUA_VERSION_MAJOR       "5"
+#define LUA_VERSION_MINOR       "4"
+#define LUA_VERSION_RELEASE     "7"
 
+#define LUA_VERSION_NUM                 504
+#define LUA_VERSION_RELEASE_NUM         (LUA_VERSION_NUM * 100 + 7)
 
-#include "luaconf.h"
+#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) 1994-2024 Lua.org, PUC-Rio"
+#define LUA_AUTHORS     "R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
 
 
 /* mark for precompiled code ('<esc>Lua') */
@@ -495,19 +496,8 @@ struct lua_Debug {
 /* }====================================================================== */
 
 
-#define LUAI_TOSTRAUX(x)        #x
-#define LUAI_TOSTR(x)           LUAI_TOSTRAUX(x)
-
-#define LUA_VERSION_MAJOR       LUAI_TOSTR(LUA_VERSION_MAJOR_N)
-#define LUA_VERSION_MINOR       LUAI_TOSTR(LUA_VERSION_MINOR_N)
-#define LUA_VERSION_RELEASE     LUAI_TOSTR(LUA_VERSION_RELEASE_N)
-
-#define LUA_VERSION     "Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
-#define LUA_RELEASE     LUA_VERSION "." LUA_VERSION_RELEASE
-
-
 /******************************************************************************
-* Copyright (C) 1994-2023 Lua.org, PUC-Rio.
+* Copyright (C) 1994-2024 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/src/3rdParty/lua/luaconf.h b/src/3rdParty/lua/luaconf.h
index acebe29..33bb580 100644
--- a/src/3rdParty/lua/luaconf.h
+++ b/src/3rdParty/lua/luaconf.h
@@ -261,7 +261,7 @@
 /*
 ** LUA_IGMARK is a mark to ignore all after it when building the
 ** module name (e.g., used to build the luaopen_ function name).
-** Typically, the sufix after the mark is the module version,
+** Typically, the suffix after the mark is the module version,
 ** as in "mod-v1.2.so".
 */
 #define LUA_IGMARK              "-"
diff --git a/src/3rdParty/lua/lundump.h b/src/3rdParty/lua/lundump.h
index bc71ced..a97676c 100644
--- a/src/3rdParty/lua/lundump.h
+++ b/src/3rdParty/lua/lundump.h
@@ -21,7 +21,7 @@
 /*
 ** Encode major-minor version in one byte, one nibble for each
 */
-#define LUAC_VERSION    (LUA_VERSION_MAJOR_N*16+LUA_VERSION_MINOR_N)
+#define LUAC_VERSION  (((LUA_VERSION_NUM / 100) * 16) + LUA_VERSION_NUM % 100)
 
 #define LUAC_FORMAT     0       /* this is the official format */
 
diff --git a/src/3rdParty/lua/lvm.c b/src/3rdParty/lua/lvm.c
index 4d71cff..fcd24e1 100644
--- a/src/3rdParty/lua/lvm.c
+++ b/src/3rdParty/lua/lvm.c
@@ -92,7 +92,7 @@ static int l_strton (const TValue *obj, TValue *result) {
   if (!cvt2num(obj))  /* is object not a string? */
     return 0;
   else {
-  TString *st = tsvalue(obj);
+    TString *st = tsvalue(obj);
     return (luaO_str2num(getstr(st), result) == tsslen(st) + 1);
   }
 }
@@ -661,7 +661,7 @@ 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 = tsslen(tsvalue(s2v(top - n - 1)));
-        if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl)) {
+        if (l_unlikely(l >= MAX_SIZE - sizeof(TString) - tl)) {
           L->top.p = top - total;  /* pop strings to avoid wasting stack */
           luaG_runerror(L, "string length overflow");
         }