#42316 [Fbk->Opn]: ArrayIterator mix refcount and reference

[titerm at lfdj dot com]

 ID:               42316
 User updated by:  titerm at lfdj dot com
 Reported By:      titerm at lfdj dot com
-Status:           Feedback
+Status:           Open
 Bug Type:         SPL related
 Operating System: Windows
 PHP Version:      5.2.3
 New Comment:

I did my test on 5.2.3 release on window and solaris.
I don't understand why you say original array is not modified since i'm
using offsetSet function, it should modified $arr and it does.

If i init $arr with $data1 and $data2 like this, only branch one is
altered.

$data1['one'] = 'ORG';
$data2['one'] = 'ORG';
$arr = array (
        'branch1' => $data1,
        'branch2' => $data2,
);


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

[2007-08-16 13:47:51] [EMAIL PROTECTED]

Since the iterator does not modify original array, this is the expected
result of your script (and what I get using latest CVS build):

array(2) {
  ["branch1"]=>
  array(1) {
    ["one"]=>
    string(3) "ORG"
  }
  ["branch2"]=>
  array(1) {
    ["one"]=>
    string(3) "ORG"
  }
}


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

[2007-08-16 12:11:48] titerm at lfdj dot com

Create a ArrayIterator on branch1. Alter the leaf by using iterator.
Leave on branch2 are affected too.

Simplified reproduce code.

$data['one'] = 'ORG';
$arr = array (
        'branch1' => $data,
        'branch2' => $data,
);
$iterator = new ArrayIterator($arr['branch1']);;
$iterator->offSetSet($iterator->key(), 'ALTER' );
var_dump($arr);

Expected result
array
  'branch1' => 
    array
      'one' => string 'ALTER' (length=5)
  'branch2' => 
    array
      'one' => string 'ORG' (length=3)


Actual result
array
  'branch1' => 
    array
      'one' => string 'ALTER' (length=5)
  'branch2' => 
    array
      'one' => string 'ALTER' (length=5)

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

[2007-08-16 10:45:42] [EMAIL PROTECTED]

What if you didn't pay attention to the internals like refcount but
only for actual results? Can you come up with a short and simple example
of what actually doesn't work?

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

[2007-08-16 08:32:05] titerm at lfdj dot com

I have simplified the reproduce code to much. Sorry

it should be

$iterator = new RecursiveIteratorIterator(new
RecursiveArrayIterator($arr['l1']));
foreach($iterator as $leaf) {
    $iterator->offSetSet($iterator->key(), 'ALTER' );
}

Expected result
array(3) refcount(2){
  ["l1"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(5) "ALTER" refcount(1)
    }
  }
  ["l2"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(3) "ORG" refcount(2)
    }
  }
  ["l3"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(3) "ORG" refcount(1)
    }
  }
}

Actual Result 
array(3) refcount(2){
  ["l1"]=>
  array(1) refcount(3){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(5) "ALTER" refcount(1)
    }
  }
  ["l2"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(3) "ORG" refcount(2)
    }
  }
  ["l3"]=>
  array(1) refcount(3){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(5) "ALTER" refcount(1)
    }
  }
}

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

[2007-08-16 08:18:32] titerm at lfdj dot com

Description:
------------
When multiple entries of an array are initialized with a $base var
array, new entries will increase refcount.
Any modification of this new entries should decrease refcount.

But if modification are done through a recursive Array Iterator,
refcount works like it was reference, and all leaf are modified

Reproduce code:
---------------
// Reference var array
$base['one']['two'] = 'ORG';

// Work array
$arr = array (
        'l1' => $base,
        'l2' => $base,
        'l3' => $base,
);
unset($base); // No need anymore of reference 

// Break refcount for level 2, level 1 and level 3 are still refcount
$arr['l2']['one']['two'] = $arr['l2']['one']['two'];

// Create an iterator on level 1
$iterator = new RecursiveIteratorIterator(new
RecursiveArrayIterator($arr['l1']));
// Alter leaf of level 1
$iterator->offSetSet($iterator->key(), 'ALTER' );
debug_zval_dump($arr);


Expected result:
----------------
array(3) refcount(2){
  ["l1"]=>
  array(1) refcount(1){
    ["one"]=>
    string(5) "ALTER" refcount(1)
  }
  ["l2"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(3) "ORG" refcount(1)
    }
  }
  ["l3"]=>
  array(1) refcount(1){
    ["one"]=>
    string(3) "ORG" refcount(1)
  }
}

Actual result:
--------------
array(3) refcount(2){
  ["l1"]=>
  array(1) refcount(3){
    ["one"]=>
    string(5) "ALTER" refcount(1)
  }
  ["l2"]=>
  array(1) refcount(1){
    ["one"]=>
    array(1) refcount(1){
      ["two"]=>
      string(3) "ORG" refcount(1)
    }
  }
  ["l3"]=>
  array(1) refcount(3){
    ["one"]=>
    string(5) "ALTER" refcount(1)
  }
}


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


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Edit this bug report at http://bugs.php.net/?id=42316&edit=1