new macro lua_userstateopen

ltests.c

@@ -254,6 +254,13 @@ static int hash_query (lua_State *L) {
 }
 
 
+static int Cstacklevel (lua_State *L) {
+  unsigned long a = 0;
+  lua_pushnumber(L, (unsigned long)&a);
+  return 1;
+}
+
+
 static int table_query (lua_State *L) {
   const Table *t;
   int i = luaL_opt_int(L, 2, -1);
@@ -368,7 +375,6 @@ static int udataval (lua_State *L) {
 static int doonnewstack (lua_State *L) {
   lua_State *L1 = lua_newthread(L, luaL_check_int(L, 1));
   if (L1 == NULL) return 0;
-  *cast(int **, L1) = &islocked;  /* initialize the lock */
   lua_dostring(L1, luaL_check_string(L, 2));
   lua_pushnumber(L, 1);
   lua_close(L1);
@@ -624,6 +630,7 @@ static const struct luaL_reg tests_funcs[] = {
   {"listk", listk},
   {"listlocals", listlocals},
   {"loadlib", loadlib},
+  {"Cstacklevel", Cstacklevel},
   {"querystr", string_query},
   {"querytab", table_query},
   {"testC", testC},