Bug #81185 [Com]: preg_match fails to match while it seemingly should

Edit report at https://bugs.php.net/bug.php?id=81185&edit=1 ID: 81185 Comment by: hans at nieser dot nl Reported by: hans at reachdigital dot nl Summary: preg_match fails to match while it seemingly should Status: Feedback Type: Bug Package: PCRE related Operating System: macOS Big Sur PHP Version: 7.4.20 Block user comment: N Private report: N New Comment: Hey there, a few colleagues of mine who are both running into this issue (I am running 7.4.20 myself so am not affected) report that adding ini_set("pcre.jit", "0") to the test script does indeed make it give the expected result Previous Comments: ------------------------------------------------------------------------ [2021-06-21 11:42:38] danack@php.net I don't get the results you seem to have: https://3v4l.org/Xl4DM Please can you test setting ini_set("pcre.jit", "0") and see if that makes a difference? ------------------------------------------------------------------------ [2021-06-21 11:35:03] hans at reachdigital dot nl Description: ------------ While debugging an issue (within Magento), I stumbled upon a case where preg_match() is giving an unexpected result compared to previous PHP versions. In our case a given pattern is matching two particular strings on older PHP versions, but fails to match one of them in PHP 7.4.16 (as well as PHP 8.0.6) Please refer to the test script I've added, which when run with PHP 7.4.16 indicates that the pattern matches both strings, but when run with PHP 7.4.20 indicates that only one string matches. Interestingly, putting something like '.+' at the beginning of the pattern makes it work as expected again Test script: --------------- $pattern = "#/(?<moduleName>[^/]+)/layout/[^/]*\.xml$#i"; $res1 = preg_match($pattern, "/Users/nickdekleijn/Sites/project-12gobiking-m2/vendor/magento/theme-adminhtml-backend/Magento_Backend/layout/default.xml", $matches); $res2 = preg_match($pattern, "/Users/wimvanderputten/Documents/gob/project-12gobiking-m2/vendor/magento/theme-adminhtml-backend/Magento_Backend/layout/default.xml", $matches); var_dump($res1); var_dump($res2); Expected result: ---------------- int(1) int(1) Actual result: -------------- int(0) int(1) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81185&edit=1