Bug #74675 [Com]: Regex that worked fine on 5.x Fails Randomly on 7.x

Edit report at https://bugs.php.net/bug.php?id=74675&edit=1 ID: 74675 Comment by: donatj at gmail dot com Reported by: donatj at gmail dot com Summary: Regex that worked fine on 5.x Fails Randomly on 7.x Status: Not a bug Type: Bug Package: PCRE related Operating System: Darwin / Linux PHP Version: 7.1.5 Block user comment: N Private report: N New Comment: Your solution regex while working on the specific input actually fails on more of my inputs than the original. Sigh. I'll accept the "not a bug" verdict but I'm not happy about the JIT's seemingly uselessness at all. Previous Comments: ------------------------------------------------------------------------ [2017-05-30 20:41:35] requinix@php.net PHP 7 introduced PCRE's JIT feature. When enabled this changes how regexes are compiled and executed. http://sljit.sourceforge.net/pcre.html preg_last_error() is returning PREG_JIT_STACKLIMIT_ERROR which means what it sounds like it means and is caused by an inefficient regex. If I alter your regex a bit by tweaking the backslash treatment and adding +s '/(?(?=")"(\\\\.|[^\\\\"]+)*"|\'(\\\\.|[^\\\\\']+)*\')/' then it executes fine on the test string (and also fixes what I assume was a bug with the original). ------------------------------------------------------------------------ [2017-05-30 20:14:56] donatj at gmail dot com Description: ------------ We use this regex (?(?=")"(\\"|[^"])*"|'(\\'|[^'])*') as part of our internal CI system as a step to clear strings. We were getting weird failures on 7.x builds and I hunted it down to the fact that this regex randomly fails on some strings in 7.x. It works in most cases, but we have 4 files where it randomly fails and returns NULL. It's worked fine prior in 5.x for years, and works on HHVM fine so something must have changed in PHP7. Test script: --------------- The issue can be seen here. https://3v4l.org/SEWZc / https://gist.github.com/donatj/b872de5cc8f755871500a82c483aa92f I boiled the input string down as much as I could manage, it's still very long. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74675&edit=1