Edit report at https://bugs.php.net/bug.php?id=62427&edit=1
ID: 62427
Updated by: ras...@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)
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=62427&edit=1
