Bug #62427 [Opn]: PCRE invalid "\k" sequence does not cause warning or error

Edit report at https://bugs.php.net/bug.php?id=62427&edit=1 ID: 62427 Updated by: rasmus@php.net Reported by: danielklein at airpost dot net Summary: PCRE invalid "\k" sequence does not cause warning or error Status: Open Type: Bug Package: PCRE related PHP Version: 5.4.4 Block user comment: N Private report: N New Comment: For reference, the command pcretest tool that comes with PCRE-8.30 gives this: re> /\k/ Failed: \k is not followed by a braced, angle-bracketed, or quoted name at offset 2 re> /\g/ Failed: a numbered reference must not be zero at offset 1 Previous Comments: ------------------------------------------------------------------------ [2012-06-27 01:22:24] danielklein at airpost dot net Description: ------------ The "\k" escape must be followed by 'name', <name> or {name}. A PCRE regex that contains "\k" without the properly quoted name will compile without an error and will always fail as "\k" can never (as far as I know) match anything in the subject string. It is almost identical to "\g", except "\g" also allows "\gn", "\g{n}" or "\g{-n}" where "n" is any positive decimal number. I have been unable to test PCRE directly (i.e. via the command line, not through PHP) as I can't compile it on my computer. I have looked through the source code and the test results, and from that it seems to be working correctly. Although I'm not 100% sure, I think this bug is specific to PHP. Test script: --------------- <?php var_dump(preg_match('/\k/', 'foo')); // Missing named reference var_dump(preg_match('/\g/', 'foo')); // Missing named or numbered reference ?> Expected result: ---------------- Warning: preg_match(): Compilation failed: **something about name missing in \k back-reference** at offset 1 in test.php on line 3 bool(false) Warning: preg_match(): Compilation failed: a numbered reference must not be zero at offset 1 in test.php on line 3 bool(false) Actual result: -------------- int(0) Warning: preg_match(): Compilation failed: a numbered reference must not be zero at offset 1 in test.php on line 3 bool(false) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=62427&edit=1