Bug #69672 [NEW]: preg_replace() does not necessarily cater to u modifier

From: cmb Operating system: * PHP version: 5.6.9 Package: PCRE related Bug Type: Bug Bug description:preg_replace() does not necessarily cater to u modifier Description: ------------ A user contributed note[1] mentions an "unexpected behavior" of preg_replace() with regard to matching only an empty subpattern. In my opinion, this is a bug, because UTF-8 encoded code points must never be split when the u modifier is set. Matching for an empty subpattern only might be regarded as a bug per se, but then at least a warning should be raised or an error should be reported by preg_last_error(). According to <http://3v4l.org/AMq5N> the current behavior has been introduced with PHP 5.2.9, and is not directly related to the PCRE library. [1] <http://php.net/manual/en/function.preg-replace.php#117314> Test script: --------------- <?php var_dump(preg_replace('/()/u', '*', "a\xc3\x84b")); ?> Expected result: ---------------- string(8) "*a*Ä*b*" Actual result: -------------- string(9) "*a*�*�*b*" -- Edit bug report at https://bugs.php.net/bug.php?id=69672&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=69672&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=69672&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=69672&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=69672&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=69672&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=69672&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=69672&r=needscript Try newer version: https://bugs.php.net/fix.php?id=69672&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=69672&r=support Expected behavior: https://bugs.php.net/fix.php?id=69672&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=69672&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=69672&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=69672&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=69672&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=69672&r=dst IIS Stability: https://bugs.php.net/fix.php?id=69672&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=69672&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=69672&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=69672&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=69672&r=mysqlcfg