Bug #54099 [NEW]: PCRE preg_match incorrectly matches negated character class

From: Operating system: Linux, Windows PHP version: 5.3.5 Package: PCRE related Bug Type: Bug Bug description:PCRE preg_match incorrectly matches negated character class Description: ------------ The perl-compatible regex matcher somehow matches a negated character class if the string to match contains the same characters, and in the same order, as the character class. I don't see why /[^ab]/ should match "ab" but not "ba". Perl agrees: $ perl -e 'for("ab","ba") { print "$_: "; if( /[^ab]/ ) {print "match\n"} else {print "no match\n"}}' ab: no match ba: no match Test script: --------------- <?php echo "expecting 0, 0, 0, 0, 0\n"; echo preg_match( '[^ab]', 'ba' ) . "\n"; // expected no match, passes echo preg_match( '[^ab]', 'ab' ) . "\n"; // expected no match, fails echo preg_match( '([^ab])', 'ab' ) . "\n"; // expected no match, passes echo preg_match( '[^ab]', 'aba' ) . "\n"; // expected no match, fails echo preg_match( '[^ab]', 'abb' ) . "\n"; // expected no match, fails echo preg_match( '([^ab])', 'abb' ) . "\n"; // expected no match, passes ?> Expected result: ---------------- expecting 0, 0, 0, 0, 0, 0 0 0 0 0 0 0 Actual result: -------------- expecting 0, 0, 0, 0, 0, 0 0 1 0 1 1 0 -- Edit bug report at http://bugs.php.net/bug.php?id=54099&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=54099&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=54099&r=trysnapshot53 Try a snapshot (trunk): http://bugs.php.net/fix.php?id=54099&r=trysnapshottrunk Fixed in SVN: http://bugs.php.net/fix.php?id=54099&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=54099&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=54099&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=54099&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=54099&r=needscript Try newer version: http://bugs.php.net/fix.php?id=54099&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=54099&r=support Expected behavior: http://bugs.php.net/fix.php?id=54099&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=54099&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=54099&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=54099&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=54099&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=54099&r=dst IIS Stability: http://bugs.php.net/fix.php?id=54099&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=54099&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=54099&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=54099&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=54099&r=mysqlcfg