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

 ID:                 52719
 Updated 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
+Status:             Re-Opened
 Type:               Bug
 Package:            Arrays related
 Operating System:   Linux
 PHP Version:        5.3.3
 Block user comment: N
 Private report:     N

 New Comment:

I added a patch that fixes the issue.

Now the function works on the userdata as zval* instead of zval**. This fixes 
the 
issue because zend_call_func changes the zval** for a by-ref var and thus 
zval_ptr_dtor() is called on a different zval than Z_ADDREF_PP() was called on.


Previous Comments:
------------------------------------------------------------------------
[2012-01-27 13:06:42] ni...@php.net

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

------------------------------------------------------------------------
[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 ===

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


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