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

From: donatj at gmail dot com Operating system: Darwin / Linux PHP version: 7.1.5 Package: PCRE related Bug Type: Bug Bug description:Regex that worked fine on 5.x Fails Randomly on 7.x 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 bug report at https://bugs.php.net/bug.php?id=74675&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=74675&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=74675&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=74675&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=74675&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=74675&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=74675&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=74675&r=needscript Try newer version: https://bugs.php.net/fix.php?id=74675&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=74675&r=support Expected behavior: https://bugs.php.net/fix.php?id=74675&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=74675&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=74675&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=74675&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=74675&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=74675&r=dst IIS Stability: https://bugs.php.net/fix.php?id=74675&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=74675&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=74675&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=74675&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=74675&r=mysqlcfg