Bug #62901 [Com]: foreach unexpectedly advances the internal array pointer

From: Date: Wed, 10 Jun 2015 13:37:28 +0000
Subject: Bug #62901 [Com]: foreach unexpectedly advances the internal array pointer
References: 1  Groups: php.bugs 
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Edit report at https://bugs.php.net/bug.php?id=62901&edit=1

 ID:                 62901
 Comment by:         arjen at react dot com
 Reported by:        david at grudl dot com
 Summary:            foreach unexpectedly advances the internal array
                     pointer
 Status:             Assigned
 Type:               Bug
 Package:            Variables related
 PHP Version:        5.4.6
 Assigned To:        laruence
 Block user comment: N
 Private report:     N

 New Comment:

This is fixed in 7.0, still fails in 5.5, 5.6.

Created a different testcase: http://3v4l.org/jH4pM

When the return value is assigned to a tmp var first, the internal pointer isn't modified.


Previous Comments:
------------------------------------------------------------------------
[2012-09-14 02:56:51] laruence@php.net

@nikic,  after we discussed yesterday,  I re-through the codes, do find a 
*inconsistent* place, assign to myself,  thanks

------------------------------------------------------------------------
[2012-09-13 16:19:15] nikic@php.net

@laruence: Changing the array pointer is a change too. That's why foreach usually copies the
passed array.

So yes, this is a bug, but from a quick glance at the code I can't yet see why it happens.

------------------------------------------------------------------------
[2012-09-13 02:45:16] laruence@php.net

s ,write on copy, copy on write,  ;<

------------------------------------------------------------------------
[2012-09-13 02:44:38] laruence@php.net

the same, although it is *copy* of a array, but still the same zval, PHP using 
"write on copy".  but the internalPointer's change is not considered as
"write" 
here.

------------------------------------------------------------------------
[2012-09-13 01:51:19] david at grudl dot com

The point is: the iteration is not started on $this->arr, but it is started on array returned
from method getArr(). 

Foreach resets internal array pointer of completely different array.

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


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