- default: /* other values */
- p += sprintf(p, "???");
-/* if ((ptr = luaL_checkudata(L,i,TASK_MODULE_NAME))) {
- p+=sprintf(p,"task");
- } else {
- p+=printf(p,"%s", lua_typename(L, t));
- }*/
- break;
-
- }
- p += sprintf(p, " "); /* put a separator */
+/**
+ * \brief Like luaL_checkudata, with additional debug logs.
+ * \param L a lua state
+ * \param ud index of the userdata to check in the stack
+ * \param tname key of the metatable of this userdata in the registry
+ */
+static void* my_checkudata(lua_State* L, int ud, const char* tname) {
+
+ XBT_DEBUG("Checking the userdata: ud = %d", ud);
+ sglua_stack_dump("my_checkudata: ", L);
+ void* p = lua_touserdata(L, ud);
+ lua_getfield(L, LUA_REGISTRYINDEX, tname);
+ const void* correct_mt = lua_topointer(L, -1);
+
+ int has_mt = lua_getmetatable(L, ud);
+ XBT_DEBUG("Checking the userdata: has metatable ? %d", has_mt);
+ const void* actual_mt = NULL;
+ if (has_mt) {
+ actual_mt = lua_topointer(L, -1);
+ lua_pop(L, 1);