Edit report at https://bugs.php.net/bug.php?id=52719&edit=1

 ID:                 52719
 Patch added by:     ni...@php.net
 Reported by:        apouch at woozworld dot com
 Summary:            array_walk_recursive crashes if third param of the
                     function is by reference
 Status:             Feedback
 Type:               Bug
 Package:            Arrays related
 Operating System:   Linux
 PHP Version:        5.3.3
 Block user comment: N
 Private report:     N

 New Comment:

The following patch has been added/updated:

Patch Name: array_walk_recursive.patch
Revision:   1327669602
URL:        
https://bugs.php.net/patch-display.php?bug=52719&patch=array_walk_recursive.patch&revision=1327669602


Previous Comments:
------------------------------------------------------------------------
[2011-12-23 11:42:08] nikita dot ppv at googlemail dot com

This issue was caused by 
http://svn.php.net/viewvc?view=revision&revision=300371 which was commited as a 
fix for https://bugs.php.net/bug.php?id=51552.

Basically for a recursive array walk the zval will be zval_ptr_dtor'd 
prematurely and multiple times (every time it leaves one recursive array_walk 
call). This leads to the memory corruption and in some cases to a segfault.

I'm not exactly sure what purpose that change served, at least the respective 
phpt test runs cleanly if I revert the changeset.

------------------------------------------------------------------------
[2011-12-21 16:16:47] ni...@php.net

Another test case: http://codepad.viper-7.com/Mw3DhS. You can observe the 
memory corruption in the values that are output. Also you can simply toggle the 
crash be removing the 'alpha' elements: http://codepad.viper-7.com/luVZw5 will 
crash.

By the way, I could not reproduce the crash on a debug build (I get only leaks 
there, too).

------------------------------------------------------------------------
[2010-12-13 13:19:19] php at oxanvanleeuwen dot nl

This is still a problem with PHP 5.3.4. Strange is that it segfaults after the 
call to array_walk_recursive; running is printed. 

See this test script, which segfaults:
<?php
$array = array("hello", array("bye"));
$flat = array();
array_walk_recursive($array, function (&$value, $key, &$flat) {
  $flat[] = $value;
}, $flat);
echo "Running";

------------------------------------------------------------------------
[2010-08-30 19:36:24] johan...@php.net

Please try using this snapshot:

  http://snaps.php.net/php5.3-latest.tar.gz
 
For Windows:

  http://windows.php.net/snapshots/

I get no crash but a memleak which is handled gracefully with current SVN.

No crash[Mon Aug 30 19:33:37 2010]  Script:  '-'
/home/johannes/src/php/php-src/branches/PHP_5_3/Zend/zend_execute_API.c(888) :  
Freeing 0x00DEB060 (32 bytes), script=-
=== Total 1 memory leaks detected ===

------------------------------------------------------------------------
[2010-08-27 22:42:39] apouch at woozworld dot com

Description:
------------
This is something that changed between PHP 5.3.2 and PHP 5.3.3.

array_walk_recursive accepts a 3rd parameter for 'userdata'.
If:
- this parameter is an object AND
- the user-created function used as second parameter to array_walk_recursive 
defines the third parameter by reference AND
- The array given as first parameter to array_walk_recursive is a 
multi-dimensional array,
PHP crashes.

Test script:
---------------
$array = array('foo', 'bar' => array('taz'));
$foo = new stdClass();
array_walk_recursive($array, create_function('&$v, $k, &$u', ''), $foo);
echo 'No crash';
//This one works: array_walk_recursive($array, create_function('&$v, $k, $u', 
''), $foo);




Expected result:
----------------
No Crash

Actual result:
--------------
PHP crashes


------------------------------------------------------------------------



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