simpler way to collect userdata

lgc.h

@@ -16,7 +16,7 @@
 
 
 void luaC_callallgcTM (lua_State *L);
-Udata *luaC_collect (lua_State *L, int all);
+void luaC_collect (lua_State *L, int all);
 void luaC_collectgarbage (lua_State *L);
 
 

lstate.c

@@ -116,6 +116,7 @@ static void close_state (lua_State *L, lua_State *OL) {
     L->next->previous = L->previous;
   }
   else if (G(L)) {  /* last thread; close global state */
+    if (G(L)->rootudata)  /* (avoid problems with incomplete states) */
       luaC_callallgcTM(L);  /* call GC tag methods for all udata */
     luaC_collect(L, 1);  /* collect all elements */
     lua_assert(G(L)->rootproto == NULL);