Edit report at https://bugs.php.net/bug.php?id=48460&edit=1
ID: 48460
Comment by: matteopuppis at gmail dot com
Reported by: ben at last dot fm
Summary: Referencing an object property causes behaviour
change after clone
Status: No Feedback
Type: Bug
Package: Scripting Engine problem
Operating System: Linux
PHP Version: 5.2.9
Block user comment: N
Private report: N
New Comment:
More simple code:
<?php
class Obj {
}
$a = new Obj();
$a->test[0] = 'pippo';
$b = clone $a;
$b->test[0] = 'pluto';
echo ($a->test[0].'<br /><br />');
$c = new Obj();
$c->test[0]->prova = 'pippo';
$d = clone $c;
$d->test[0]->prova = 'pluto';
echo ($c->test[0]->prova);
?>
Expected result: "pippo pippo"
Actual result: "pippo pluto"
Previous Comments:
------------------------------------------------------------------------
[2009-09-26 01:00:03] php-bugs at lists dot php dot net
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
------------------------------------------------------------------------
[2009-09-18 19:01:59] [email protected]
Please try using this snapshot:
http://snaps.php.net/php5.3-latest.tar.gz
For Windows:
http://windows.php.net/snapshots/
------------------------------------------------------------------------
[2009-06-03 15:26:16] ben at last dot fm
Hmm.
The bug is that you can alter the behaviour of clone (that is, force $d-
>list to be copied-by-reference instead of copied-by-value) merely by
creating any other reference to $a->list. 'clone' is, therefore, the
only language construct (that I know of) which is capable of this, and
is NOT the same as "$b = new A; $b->list = $a->list".
There is in fact no way to tell whether a property is a reference or not
without cloning the entire object and seeing what happens when you
change the clone's property; or by forcibly unsetting and resetting the
property.
------------------------------------------------------------------------
[2009-06-03 13:54:41] [email protected]
This is quite expected, that's basically the same as:
$a = array(2);
$d = &$a[0];
$a_copy = $a;
$a_copy[0]++;
echo $a[0],$d; // 3 3
You can do a deep copy using the __clone hook.
OTOH I'm not sure if clone shouldn't separate the properties directly, instead
of simply assigning them.
------------------------------------------------------------------------
[2009-06-03 13:34:44] ben at last dot fm
Sorry, put this in the wrong category.
------------------------------------------------------------------------
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the rest of the comments, please view the bug report online at
https://bugs.php.net/bug.php?id=48460
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Edit this bug report at https://bugs.php.net/bug.php?id=48460&edit=1
