ID:               42236
 User updated by:  remy215 at laposte dot net
 Reported By:      remy215 at laposte dot net
-Status:           Feedback
+Status:           Open
 Bug Type:         Arrays related
 Operating System: debian
 PHP Version:      5.2CVS-2007-08-12
 New Comment:

I know that foreach reset the array.
In fact I am not looking for a workaround, I already have one.
It's just that the behavior of php looks quite unexpected to me and it
could be a bug.

Normally, calling << getParent('a0'); >> or calling <<
getParent('a0',$array); >> should lead exactly to the same result since 
when the second argument is not provided, it defaults to $array.
But that's not the case, the first call leads to an infinite loop while
the second delivers the expected result (null).

I hope I am not wrong. In any case, thanks for your help.
Regards,
Remy


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

[2007-08-15 15:46:41] [EMAIL PROTECTED]

Try replace the foreach() calls with while/each struct...foreach() does
a reset on the array..

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

[2007-08-15 12:47:01] remy215 at laposte dot net

Hi Jani,
First thank you for your support.
Here is a cleaner version (without the infinite-loop checking):
<?php
$array=array(
        'a0'=>array(
                'a1'=>array(
                        'a2'=>array(),
                        'b2'=>array()
                ),'b1'=>array()
        ),'b0'=>array()
);

function getParent($id,$_subtree=null) {
        $found_parent=null;
        if(!$_subtree) {
                global $array;
                $_subtree=$array;
        }
        foreach($_subtree as $parent=>$children) {
                if(in_array($id,array_keys($children))) {
                        $found_parent=$parent;
                        break;
                } elseif($found_parent=getParent($id,$children)) {
                        break;
                }
        }
        return $found_parent;
}
echo "\nparent of b2 is: ".getParent('b2'); // expected result: 'a1' --
actual result: 'a1'
echo "\nparent of a0 is: ".getParent('a0'); // expected result: null --
actual result: infinite loop
?>

What's really strange is that if you call getParent('a0',$array), it
works perfectly ! it's the [global $array; $_subtree=$array;] used for
initialization that triggers an infinite loop.

Regards,
Remy

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

[2007-08-15 08:44:39] [EMAIL PROTECTED]

Please provide the simplest possible script that shows exactly what is
going wrong. The current example is too complex and seems to contain all
kinds of useless workarounds..

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

[2007-08-12 21:36:09] remy215 at laposte dot net

I tested with latest cvs snapshot, still unexpectingly reseting the
array, leading to an unpredictable infinite loop.

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

[2007-08-07 17:21:17] remy215 at laposte dot net

Description:
------------
I have an array of nested arrays (ie. each id can have nested
children). The function returns the parent of the provided id but end in
an infinite loop when the id does not exists !
Parent array at the top of the hierarchy seems to undergo an unwanted
reset();


Reproduce code:
---------------
<?php
$array=array('a0'=>array('a1'=>array('a2'=>array(),'b2'=>array()),'b1'=>array()),'b0'=>array());
$searched=array(); // to avoid infinite loop
function getParent($id,$_subtree=null) {
        if(!$_subtree) { // if first call
                global $array;
                $_subtree=$array; // entire tree
        }
        global $searched; // to avoid infinite loop
        $found_parent=null;
        foreach($_subtree as $parent=>$children) {
                if(in_array($parent,$searched)) { // if already looped => stop 
(ie.
infinite loop)
                        die('Infinite loop: '.$parent);
                }
                array_push($searched,$parent); // to avoid infinite loop
                if(in_array($id,array_keys($children))) {
                        $found_parent=$parent;
                        break;
                } elseif($found_parent=getParent($id,$children)) {
                        break;
                }
        }
        return $found_parent;
}
$search='a0';
echo 'parent of '.$search.' is: '.getParent($search);
?>

Expected result:
----------------
When you provide as argument a nested id, the function works ('b2'
returns 'a1').
When you provide a non-existing id, or one of the top parent ids ('a0'
or 'b0') the function should return null.

Actual result:
--------------
When you provide a non-existing id, or one of the top parent ids ('a0'
or 'b0') the function end up in an infinite loop.
Parent array at the top of the hierarchy seems to undergo an unwanted
reset();



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


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