Details

- 'luaL_setfuncs' avoids creating closures for placeholders.
- Fixed some warnings about unused values in comma expressions.
- Comments.

lauxlib.c

@@ -898,9 +898,13 @@ 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 */
     int i;
-    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
-      lua_pushvalue(L, -nup);
-    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    if (l->func == NULL)  /* place holder? */
+      lua_pushboolean(L, 0);
+    else {
+      for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+        lua_pushvalue(L, -nup);
+      lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    }
     lua_setfield(L, -(nup + 2), l->name);
   }
   lua_pop(L, nup);  /* remove upvalues */