diff --git a/src/mod/languages/mod_lua/lua/lapi.c b/src/mod/languages/mod_lua/lua/lapi.c
index d7e8931e45..5d5145d2eb 100644
--- a/src/mod/languages/mod_lua/lua/lapi.c
+++ b/src/mod/languages/mod_lua/lua/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.55.1.3 2008/01/03 15:20:39 roberto Exp $
+** $Id: lapi.c,v 2.55.1.5 2008/07/04 18:41:18 roberto Exp $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -93,15 +93,14 @@ void luaA_pushobject (lua_State *L, const TValue *o) {
 
 
 LUA_API int lua_checkstack (lua_State *L, int size) {
-  int res;
+  int res = 1;
   lua_lock(L);
-  if ((L->top - L->base + size) > LUAI_MAXCSTACK)
+  if (size > LUAI_MAXCSTACK || (L->top - L->base + size) > LUAI_MAXCSTACK)
     res = 0;  /* stack overflow */
-  else {
+  else if (size > 0) {
     luaD_checkstack(L, size);
     if (L->ci->top < L->top + size)
       L->ci->top = L->top + size;
-    res = 1;
   }
   lua_unlock(L);
   return res;
@@ -930,10 +929,13 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
         g->GCthreshold = g->totalbytes - a;
       else
         g->GCthreshold = 0;
-      while (g->GCthreshold <= g->totalbytes)
+      while (g->GCthreshold <= g->totalbytes) {
         luaC_step(L);
-      if (g->gcstate == GCSpause)  /* end of cycle? */
-        res = 1;  /* signal it */
+        if (g->gcstate == GCSpause) {  /* end of cycle? */
+          res = 1;  /* signal it */
+          break;
+        }
+      }
       break;
     }
     case LUA_GCSETPAUSE: {
diff --git a/src/mod/languages/mod_lua/lua/lbaselib.c b/src/mod/languages/mod_lua/lua/lbaselib.c
index eb06bcef86..2a4c079d3b 100644
--- a/src/mod/languages/mod_lua/lua/lbaselib.c
+++ b/src/mod/languages/mod_lua/lua/lbaselib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.191.1.4 2008/01/20 13:53:22 roberto Exp $
+** $Id: lbaselib.c,v 1.191.1.6 2008/02/14 16:46:22 roberto Exp $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -344,10 +344,12 @@ static int luaB_unpack (lua_State *L) {
   luaL_checktype(L, 1, LUA_TTABLE);
   i = luaL_optint(L, 2, 1);
   e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
+  if (i > e) return 0;  /* empty range */
   n = e - i + 1;  /* number of elements */
-  if (n <= 0) return 0;  /* empty range */
-  luaL_checkstack(L, n, "table too big to unpack");
-  for (; i<=e; i++)  /* push arg[i...e] */
+  if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */
+    return luaL_error(L, "too many results to unpack");
+  lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */
+  while (i++ < e)  /* push arg[i + 1...e] */
     lua_rawgeti(L, 1, i);
   return n;
 }
@@ -526,7 +528,7 @@ static int auxresume (lua_State *L, lua_State *co, int narg) {
   status = lua_resume(co, narg);
   if (status == 0 || status == LUA_YIELD) {
     int nres = lua_gettop(co);
-    if (!lua_checkstack(L, nres))
+    if (!lua_checkstack(L, nres + 1))
       luaL_error(L, "too many results to resume");
     lua_xmove(co, L, nres);  /* move yielded values */
     return nres;
diff --git a/src/mod/languages/mod_lua/lua/ldebug.c b/src/mod/languages/mod_lua/lua/ldebug.c
index 9eac4a9b41..50ad3d3803 100644
--- a/src/mod/languages/mod_lua/lua/ldebug.c
+++ b/src/mod/languages/mod_lua/lua/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.29.1.3 2007/12/28 15:32:23 roberto Exp $
+** $Id: ldebug.c,v 2.29.1.6 2008/05/08 16:56:26 roberto Exp $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -275,12 +275,12 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
 
 static int precheck (const Proto *pt) {
   check(pt->maxstacksize <= MAXSTACK);
-  lua_assert(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
-  lua_assert(!(pt->is_vararg & VARARG_NEEDSARG) ||
+  check(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
+  check(!(pt->is_vararg & VARARG_NEEDSARG) ||
               (pt->is_vararg & VARARG_HASARG));
   check(pt->sizeupvalues <= pt->nups);
   check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
-  check(GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
+  check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
   return 1;
 }
 
@@ -346,9 +346,18 @@ static Instruction symbexec (const Proto *pt, int lastpc, int reg) {
           int dest = pc+1+b;
           check(0 <= dest && dest < pt->sizecode);
           if (dest > 0) {
-            /* cannot jump to a setlist count */
-            Instruction d = pt->code[dest-1];
-            check(!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0));
+            int j;
+            /* check that it does not jump to a setlist count; this
+               is tricky, because the count from a previous setlist may
+               have the same value of an invalid setlist; so, we must
+               go all the way back to the first of them (if any) */
+            for (j = 0; j < dest; j++) {
+              Instruction d = pt->code[dest-1-j];
+              if (!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0)) break;
+            }
+            /* if 'j' is even, previous value is not a setlist (even if
+               it looks like one) */
+            check((j&1) == 0);
           }
         }
         break;
@@ -363,7 +372,11 @@ static Instruction symbexec (const Proto *pt, int lastpc, int reg) {
     }
     switch (op) {
       case OP_LOADBOOL: {
-        check(c == 0 || pc+2 < pt->sizecode);  /* check its jump */
+        if (c == 1) {  /* does it jump? */
+          check(pc+2 < pt->sizecode);  /* check its jump */
+          check(GET_OPCODE(pt->code[pc+1]) != OP_SETLIST ||
+                GETARG_C(pt->code[pc+1]) != 0);
+        }
         break;
       }
       case OP_LOADNIL: {
@@ -428,7 +441,10 @@ static Instruction symbexec (const Proto *pt, int lastpc, int reg) {
       }
       case OP_SETLIST: {
         if (b > 0) checkreg(pt, a + b);
-        if (c == 0) pc++;
+        if (c == 0) {
+          pc++;
+          check(pc < pt->sizecode - 1);
+        }
         break;
       }
       case OP_CLOSURE: {
diff --git a/src/mod/languages/mod_lua/lua/loadlib.c b/src/mod/languages/mod_lua/lua/loadlib.c
index d955f3ef41..0d401eba1c 100644
--- a/src/mod/languages/mod_lua/lua/loadlib.c
+++ b/src/mod/languages/mod_lua/lua/loadlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loadlib.c,v 1.52.1.2 2007/12/28 14:58:43 roberto Exp $
+** $Id: loadlib.c,v 1.52.1.3 2008/08/06 13:29:28 roberto Exp $
 ** Dynamic library loader for Lua
 ** See Copyright Notice in lua.h
 **
@@ -506,8 +506,10 @@ static int ll_require (lua_State *L) {
 
 static void setfenv (lua_State *L) {
   lua_Debug ar;
-  lua_getstack(L, 1, &ar);
-  lua_getinfo(L, "f", &ar);
+  if (lua_getstack(L, 1, &ar) == 0 ||
+      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
+      lua_iscfunction(L, -1))
+    luaL_error(L, LUA_QL("module") " not called from a Lua function");
   lua_pushvalue(L, -2);
   lua_setfenv(L, -2);
   lua_pop(L, 1);
diff --git a/src/mod/languages/mod_lua/lua/lobject.h b/src/mod/languages/mod_lua/lua/lobject.h
index e7199dfc68..f1e447ef3b 100644
--- a/src/mod/languages/mod_lua/lua/lobject.h
+++ b/src/mod/languages/mod_lua/lua/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 2.20.1.1 2007/12/27 13:02:25 roberto Exp $
+** $Id: lobject.h,v 2.20.1.2 2008/08/06 13:29:48 roberto Exp $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -208,7 +208,7 @@ typedef union TString {
 
 
 #define getstr(ts)	cast(const char *, (ts) + 1)
-#define svalue(o)       getstr(tsvalue(o))
+#define svalue(o)       getstr(rawtsvalue(o))
 
 
 
diff --git a/src/mod/languages/mod_lua/lua/lstrlib.c b/src/mod/languages/mod_lua/lua/lstrlib.c
index ca333ba168..1b4763d4ee 100644
--- a/src/mod/languages/mod_lua/lua/lstrlib.c
+++ b/src/mod/languages/mod_lua/lua/lstrlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.132.1.3 2007/12/28 15:32:23 roberto Exp $
+** $Id: lstrlib.c,v 1.132.1.4 2008/07/11 17:27:21 roberto Exp $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -35,7 +35,8 @@ static int str_len (lua_State *L) {
 
 static ptrdiff_t posrelat (ptrdiff_t pos, size_t len) {
   /* relative string position: negative means back from end */
-  return (pos>=0) ? pos : (ptrdiff_t)len+pos+1;
+  if (pos < 0) pos += (ptrdiff_t)len + 1;
+  return (pos >= 0) ? pos : 0;
 }
 
 
diff --git a/src/mod/languages/mod_lua/lua/ltablib.c b/src/mod/languages/mod_lua/lua/ltablib.c
index 06f1c37be1..b6d9cb4ac7 100644
--- a/src/mod/languages/mod_lua/lua/ltablib.c
+++ b/src/mod/languages/mod_lua/lua/ltablib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltablib.c,v 1.38.1.2 2007/12/28 15:32:23 roberto Exp $
+** $Id: ltablib.c,v 1.38.1.3 2008/02/14 16:46:58 roberto Exp $
 ** Library for Table Manipulation
 ** See Copyright Notice in lua.h
 */
@@ -132,6 +132,15 @@ static int tremove (lua_State *L) {
 }
 
 
+static void addfield (lua_State *L, luaL_Buffer *b, int i) {
+  lua_rawgeti(L, 1, i);
+  if (!lua_isstring(L, -1))
+    luaL_error(L, "invalid value (%s) at index %d in table for "
+                  LUA_QL("concat"), luaL_typename(L, -1), i);
+    luaL_addvalue(b);
+}
+
+
 static int tconcat (lua_State *L) {
   luaL_Buffer b;
   size_t lsep;
@@ -141,13 +150,12 @@ static int tconcat (lua_State *L) {
   i = luaL_optint(L, 3, 1);
   last = luaL_opt(L, luaL_checkint, 4, luaL_getn(L, 1));
   luaL_buffinit(L, &b);
-  for (; i <= last; i++) {
-    lua_rawgeti(L, 1, i);
-    luaL_argcheck(L, lua_isstring(L, -1), 1, "table contains non-strings");
-    luaL_addvalue(&b);
-    if (i != last)
-      luaL_addlstring(&b, sep, lsep);
+  for (; i < last; i++) {
+    addfield(L, &b, i);
+    luaL_addlstring(&b, sep, lsep);
   }
+  if (i == last)  /* add last value (if interval was not empty) */
+    addfield(L, &b, i);
   luaL_pushresult(&b);
   return 1;
 }
diff --git a/src/mod/languages/mod_lua/lua/lua.h b/src/mod/languages/mod_lua/lua/lua.h
index 5bc97b746f..e4bdfd3b94 100644
--- a/src/mod/languages/mod_lua/lua/lua.h
+++ b/src/mod/languages/mod_lua/lua/lua.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.218.1.4 2008/01/03 15:41:15 roberto Exp $
+** $Id: lua.h,v 1.218.1.5 2008/08/06 13:30:12 roberto Exp $
 ** Lua - An Extensible Extension Language
 ** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
@@ -17,7 +17,7 @@
 
 
 #define LUA_VERSION	"Lua 5.1"
-#define LUA_RELEASE	"Lua 5.1.3"
+#define LUA_RELEASE	"Lua 5.1.4"
 #define LUA_VERSION_NUM	501
 #define LUA_COPYRIGHT	"Copyright (C) 1994-2008 Lua.org, PUC-Rio"
 #define LUA_AUTHORS 	"R. Ierusalimschy, L. H. de Figueiredo & W. Celes"
diff --git a/src/mod/languages/mod_lua/lua/luaconf.h b/src/mod/languages/mod_lua/lua/luaconf.h
index eb2f5a1f71..5e7b98be65 100644
--- a/src/mod/languages/mod_lua/lua/luaconf.h
+++ b/src/mod/languages/mod_lua/lua/luaconf.h
@@ -1,5 +1,5 @@
 /*
-** $Id: luaconf.h,v 1.82.1.6 2008/01/18 17:07:48 roberto Exp $
+** $Id: luaconf.h,v 1.82.1.7 2008/02/11 16:25:08 roberto Exp $
 ** Configuration file for Lua
 ** See Copyright Notice in lua.h
 */
@@ -91,7 +91,7 @@
 		".\\?.lua;"  LUA_LDIR"?.lua;"  LUA_LDIR"?\\init.lua;" \
 		             LUA_CDIR"?.lua;"  LUA_CDIR"?\\init.lua"
 #define LUA_CPATH_DEFAULT \
-	".\\?.dll;"  LUA_CDIR"?.dll;" LUA_CDIR"loadall.dll"
+	".\\?.dll;"  ".\\?51.dll;"  LUA_CDIR"?.dll;" LUA_CDIR"?51.dll;" LUA_CDIR"clibs\\?.dll;" LUA_CDIR"clibs\\?51.dll;" LUA_CDIR"loadall.dll;" LUA_CDIR"clibs\\loadall.dll"
 
 #else
 #define LUA_ROOT	"/usr/local/"
@@ -101,7 +101,7 @@
 		"./?.lua;"  LUA_LDIR"?.lua;"  LUA_LDIR"?/init.lua;" \
 		            LUA_CDIR"?.lua;"  LUA_CDIR"?/init.lua"
 #define LUA_CPATH_DEFAULT \
-	"./?.so;"  LUA_CDIR"?.so;" LUA_CDIR"loadall.so"
+	"./?.so;"  "./lib?51.so;"  LUA_CDIR"?.so;" LUA_CDIR"lib?51.so;" LUA_CDIR"loadall.so"
 #endif
 
 
@@ -440,10 +440,10 @@
 @* can use.
 ** CHANGE it if you need lots of (Lua) stack space for your C
 ** functions. This limit is arbitrary; its only purpose is to stop C
-** functions to consume unlimited stack space.
+** functions to consume unlimited stack space. (must be smaller than
+** -LUA_REGISTRYINDEX)
 */
-#define LUAI_MCS_AUX	((int)(INT_MAX / (4*sizeof(LUA_NUMBER))))
-#define LUAI_MAXCSTACK	(LUAI_MCS_AUX > SHRT_MAX ? SHRT_MAX : LUAI_MCS_AUX)
+#define LUAI_MAXCSTACK	8000
 
 
 
diff --git a/src/mod/languages/mod_lua/lua/lundump.c b/src/mod/languages/mod_lua/lua/lundump.c
index 731c064553..8010a45795 100644
--- a/src/mod/languages/mod_lua/lua/lundump.c
+++ b/src/mod/languages/mod_lua/lua/lundump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.c,v 2.7.1.2 2008/01/18 16:39:11 roberto Exp $
+** $Id: lundump.c,v 2.7.1.4 2008/04/04 19:51:41 roberto Exp $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -48,7 +48,6 @@ static void error(LoadState* S, const char* why)
 static void LoadBlock(LoadState* S, void* b, size_t size)
 {
  size_t r=luaZ_read(S->Z,b,size);
- UNUSED(r);
  IF (r!=0, "unexpected end");
 }
 
@@ -115,7 +114,7 @@ static void LoadConstants(LoadState* S, Proto* f)
    	setnilvalue(o);
 	break;
    case LUA_TBOOLEAN:
-   	setbvalue(o,LoadChar(S));
+   	setbvalue(o,LoadChar(S)!=0);
 	break;
    case LUA_TNUMBER:
 	setnvalue(o,LoadNumber(S));
@@ -161,7 +160,9 @@ static void LoadDebug(LoadState* S, Proto* f)
 
 static Proto* LoadFunction(LoadState* S, TString* p)
 {
- Proto* f=luaF_newproto(S->L);
+ Proto* f;
+ if (++S->L->nCcalls > LUAI_MAXCCALLS) error(S,"code too deep");
+ f=luaF_newproto(S->L);
  setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
  f->source=LoadString(S); if (f->source==NULL) f->source=p;
  f->linedefined=LoadInt(S);
@@ -175,6 +176,7 @@ static Proto* LoadFunction(LoadState* S, TString* p)
  LoadDebug(S,f);
  IF (!luaG_checkcode(f), "bad code");
  S->L->top--;
+ S->L->nCcalls--;
  return f;
 }