Edit report at https://bugs.php.net/bug.php?id=70699&edit=1
ID: 70699
Updated by: rasmus@php.net
Reported by: bugs dot php dot net at ss dot st dot tc
Summary: Regex limits on repeating patterns
Status: Open
Type: Bug
Package: *Regular Expressions
Operating System: OSX and Linux
PHP Version: 7.0.0RC4
Block user comment: N
Private report: N
New Comment:
This is getting more into a PCRE question than a PHP one. See: http://www.pcre.org/original/doc/html/pcrejit.html
where it says:
The error code PCRE_ERROR_MATCHLIMIT is returned by the JIT code if searching a
very large pattern tree goes on for too long, as it is in the same
circumstance when JIT is not used, but the details of exactly what is counted
are not the same. The PCRE_ERROR_RECURSIONLIMIT error code is never returned
by JIT execution.
Previous Comments:
------------------------------------------------------------------------
[2015-10-12 22:01:17] bugs dot php dot net at ss dot st dot tc
You're right Rasmus, jit was the reason. So how do we control the limits with jit then?
------------------------------------------------------------------------
[2015-10-12 21:37:25] rasmus@php.net
The limits work a bit different with the jit enabled I think. I bet if you set pcre.jit=0 in PHP 7
you will get the same result.
------------------------------------------------------------------------
[2015-10-12 21:32:05] bugs dot php dot net at ss dot st dot tc
pcre.backtrack_limit is set to default value of 1000000 in both configurations.
------------------------------------------------------------------------
[2015-10-12 20:32:45] requinix@php.net
You're probably hitting the backtrack limit in PCRE. Compare the values of the
pcre.backtrack_limit setting on your two setups.
------------------------------------------------------------------------
[2015-10-12 19:25:29] bugs dot php dot net at ss dot st dot tc
Description:
------------
Following examples work well in PHP 5, but fail to produce correct results in PHP 7.
Test script:
---------------
<?php
echo preg_match('/((A)+)/', str_repeat('A', 1363)) ? 1 : 0, PHP_EOL;
echo preg_match('/((A)+)/', str_repeat('A', 1364)) ? 1 : 0, PHP_EOL;
echo preg_match('/((A)*)/', str_repeat('A', 1363)) ? 1 : 0, PHP_EOL;
echo preg_match('/((A)*)/', str_repeat('A', 1364)) ? 1 : 0, PHP_EOL;
echo preg_match_all('/((A)+)/', str_repeat('A', 1363)) ? 1 : 0, PHP_EOL;
echo preg_match_all('/((A)+)/', str_repeat('A', 1364)) ? 1 : 0, PHP_EOL;
echo preg_match_all('/((A)*)/', str_repeat('A', 1363)) ? 1 : 0, PHP_EOL;
echo preg_match_all('/((A)*)/', str_repeat('A', 1364)) ? 1 : 0, PHP_EOL;
Expected result:
----------------
Both PHP 5 and 7:
1
1
1
1
1
1
1
1
Actual result:
--------------
PHP 5:
1
1
1
1
1
1
1
1
PHP 7:
1
0
1
0
1
0
1
0
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=70699&edit=1