--- lua-5.1.4.orig/src/llex.c	2007/12/28 15:32:23	2.63.1.3
+++ lua-5.1.4/src/llex.c	2010/02/23 12:36:59
@@ -118,8 +118,10 @@
   lua_State *L = ls->L;
   TString *ts = luaS_newlstr(L, str, l);
   TValue *o = luaH_setstr(L, ls->fs->h, ts);  /* entry for `str' */
-  if (ttisnil(o))
+  if (ttisnil(o)) {
     setbvalue(o, 1);  /* make sure `str' will not be collected */
+    luaC_checkGC(L);
+  }
   return ts;
 }