--TEST-- Ensure callback methods in unknown classes trigger autoload. --FILE-- <?php function __autoload($name) { echo "In autoload: "; var_dump($name); } call_user_func("UndefC::test"); ?> --EXPECTF-- In autoload: string(6) "UndefC" Warning: call_user_func() expects parameter 1 to be a valid callback, class 'UndefC' not found in %s on line %d