1--TEST-- 2Test preg_match() function : error conditions - Internal error 3--FILE-- 4<?php 5 6var_dump(preg_match('/', 'Hello world')); 7var_dump(preg_last_error_msg() === 'Internal error'); 8 9?> 10--EXPECTF-- 11Warning: preg_match(): No ending delimiter '/' found in %s on line %d 12bool(false) 13bool(true) 14