Bug #62135 [Nab]: Closure->bindTo plus $this reassign = corruption
| From: | Sjon at hortensius dot net | Date: | Thu, 24 May 2012 10:45:22 +0000 |
| Subject: | Bug #62135 [Nab]: Closure->bindTo plus $this reassign = corruption | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-170767@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=62135&edit=1
ID: 62135
User updated by: Sjon at hortensius dot net
Reported by: Sjon at hortensius dot net
Summary: Closure->bindTo plus $this reassign = corruption
Status: Not a bug
Type: Bug
Package: Scripting Engine problem
Operating System: ArchLinux
PHP Version: 5.4.3
Block user comment: N
Private report: N
New Comment:
Ah, too bad; I should have tested that. Thanks for your explanation!
Previous Comments:
------------------------------------------------------------------------
[2012-05-24 10:02:50] johannes@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
With the "can not reassign $this" message we try to prevent mistakes. For performance and
architecture reasons we can't prevent all ways one can shoot in one own's foot though.
your behavior also isn't closure related:
class A {
public$a = "public";
function __construct() {
$x =& $this;
$x = new stdClass;
var_dump($this, $this->a);
}
}
new A();
will show the same result. The difference between $this and $this->a comes from the fact that
$this is some magic variable.
------------------------------------------------------------------------
[2012-05-24 09:25:58] Sjon at hortensius dot net
Description:
------------
I just found the bindTo method on a Closure, a started to play with it. I found
out I can get some serieusly strange behaviour by re-assigning $this. Somehow I
end up with one variable pointing to different objects?
Test script:
---------------
From: http://3v4l.org/bp598#v540
<?php
class A
{
public $a = 'public';
}
$m = function (){
$x =& $this;
$x = new stdClass;
var_dump($this, $this->a);
};
$a = new A;
$m = $m->bindTo($a);
$m();
Expected result:
----------------
* Cannot re-assign $this OR
* 'stdClass' + Notice OR
* 'A' + 'public
Actual result:
--------------
object(stdClass)#1 (0) {
}
string(6) "public"
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=62135&edit=1