1--TEST-- 2Bug #75539 - Recursive call errors are not reported by preg_last_error() 3--FILE-- 4<?php 5 6var_dump(preg_match('/((?1)?z)/', '')); 7var_dump(preg_last_error() === \PREG_INTERNAL_ERROR); 8 9?> 10--EXPECTF-- 11Warning: preg_match(): Compilation failed: recursive call could loop indefinitely at offset %s in %s on line %s 12bool(false) 13bool(true)