#43505 [Asn->Csd]: Assign by reference bug

[dmitry]

 ID:               43505
 Updated by:       [EMAIL PROTECTED]
 Reported By:      vidmich at gmail dot com
-Status:           Assigned
+Status:           Closed
 Bug Type:         Scripting Engine problem
 Operating System: Windows
 PHP Version:      5.2.5
 Assigned To:      dmitry
 New Comment:

This bug has been fixed in CVS.

Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
 
Thank you for the report, and for helping us make PHP better.




Previous Comments:
------------------------------------------------------------------------

[2007-12-05 17:45:41] vidmich at gmail dot com

Description:
------------
Recently I came across a bug in my work with Zend Framework linked with
Smarty. In my investigation I found strange feature of PHP about
creation new element in array if we assign by ref some undefined index
from it  (ZEND_FETCH_DIM_W implementation). For example:

$a = array();
$b =& $a['test’];

After this code array $a will get new element indexed as “test” and
pointing to NULL. This is strange and I didn’t find documentation for
this, but this is rather a feature than a bug.

But I found situation in which above code return _different_ result,
which is really bad and breaks Smarty plugins loading. This situation
happened when we return undefined field in count function in Countable
object. For example

class Test implements Countable
{
  public function count()
  {
    return $this->test;
  }
}

In my opinion calling count on such object (object of class Test) break
global variable in Zend Engine named “uninitialized_zval” and as a
result new created elements point to int(0) instead of NULL

Please make this feature more predictable


Reproduce code:
---------------
<?php

class Test implements Countable
{
    public function count()
    {
        return $this->some;
    }
}

$obj = new Test();

$a = array();
$b =& $a['test'];
var_dump($a);

$t = count($obj);

$a = array();
$b =& $a['test'];
var_dump($a);


Expected result:
----------------
array(1) {
  ["test"]=>
  &NULL
}

array(1) {
  ["test"]=>
  &NULL
}


Actual result:
--------------
array(1) {
  ["test"]=>
  &NULL
}

array(1) {
  ["test"]=>
  &int(0)
}



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


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Edit this bug report at http://bugs.php.net/?id=43505&edit=1