Bug #79028 [NEW]: Several same-name subpatterns in distinct piped alternatives should be allowed

From: php4fan at gmail dot com Operating system: PHP version: 7.2.26 Package: *Regular Expressions Bug Type: Bug Bug description:Several same-name subpatterns in distinct piped alternatives should be allowed Description: ------------ see below test script and expected and observed behavior below. Maybe this an issue at the level of regular expressions specifications. As I only use them in PHP, I don't know, so I report it here. Also, it's so evidently flawed that maybe PHP could implement them correctly anyway while waiting for the specs to be fixed; not sure about that. Test script: --------------- <?php $content = <<<'HERE' First match: foo::"XYZ" Second match: bar--<XYZ> HERE; $content=preg_replace_callback('#foo::"(?<sub>[^"]*)"|bar--<(?<sub>[^>]*)>#', 'testReplace', $content); function testReplace($match) { print_r($match); return 'XXX'; } Expected result: ---------------- Array ( [0] => foo::"XYZ" [sub] => XYZ [1] => XYZ ) Array ( [0] => bar--<XYZ> [1] => [sub] => XYZ [2] => XYZ ) Actual result: -------------- Warning: preg_replace_callback(): Compilation failed: two named subpatterns have the same name Because the subgroups with the same name appear on two sides of a "|", there should be no conflict. At most one of the piped patterns (i.e. either side of the "|") can match, they are mutually exclusive, so there is no ambiguity possible and it should be a problem that a subgroup appear in both of them with the same name, as it can only be assigned once anyway. -- Edit bug report at https://bugs.php.net/bug.php?id=79028&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=79028&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=79028&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=79028&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=79028&r=needscript Try newer version: https://bugs.php.net/fix.php?id=79028&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=79028&r=support Expected behavior: https://bugs.php.net/fix.php?id=79028&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=79028&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=79028&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=79028&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=79028&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=79028&r=dst IIS Stability: https://bugs.php.net/fix.php?id=79028&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=79028&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=79028&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=79028&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=79028&r=mysqlcfg