ID: 34358
Updated by: dmitry@php.net
Reported By: pacha dot shevaev at gmail dot com
-Status: Bogus
+Status: Closed
Bug Type: Scripting Engine problem
Operating System: *
PHP Version: 5.*
-Assigned To:
+Assigned To: dmitry
New Comment:
Fixed in CVS HEAD and PHP_5_1.
Previous Comments:
------------------------------------------------------------------------
[2005-10-03 09:40:14] rasmus@php.net
It has everything to do with the new object model. Take this code:
$x = &$this;
$x = 'foo';
For performance reasons we need to catch such references when they
happen in order to prevent the object being overwritten inside itself.
It would be a bit less confusing if the error happened on the actual
assignment, but in this new object model there $x = &$this; is just as
wrong as $this = &$x since the only purpose one could have for making a
reference to $this itself is if you wanted to change it directly. In
all valid cases this should be $x = $this.
I suppose an option would be to ignore the reference in this case and
continue on. That seems to be happening with that last indirect case
you posted, but it would cost us a lookup.
------------------------------------------------------------------------
[2005-09-15 15:32:13] pacha dot shevaev at gmail dot com
And why does the following code work then???
<?php
class Foo {
function Foo() {
$this->ref =& $this;
$this->ref->test();
}
function test() {
echo 'test';
}
}
$foo = new Foo();
?>
------------------------------------------------------------------------
[2005-09-15 15:28:02] derick@php.net
It's still bogus, you can call it a BC break if you want, but we're not
going to change this back.
------------------------------------------------------------------------
[2005-09-15 15:23:37] pacha dot shevaev at gmail dot com
I'm not an expert in PHP internals but there's a guy(stereofrog) on the
SitePoint forum who has a different point of
view(http://www.sitepoint.com/forums/showpost.php?p=2146304&postcount=9):
[quote]
it's 'simply ridiculous. They have a code in zend_compile.c that
handles "$this=$x" and copy-pasted that code in the function that
comples assignment by reference. This should prevent "$this=&$x" (which
is wrong), but for some reason it "prevents" "$x=&$this" as well (which
is absolutely correct). It's pure c-level bug and has nothing to do
with "new object model" and other blah-blah.
[/quote]
------------------------------------------------------------------------
[2005-09-15 14:27:03] sniper@php.net
NOTE: This is about PHP 5. It might have worked in PHP 4 but it does
not and will not work in PHP 5.
------------------------------------------------------------------------
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http://bugs.php.net/34358--
Edit this bug report at http://bugs.php.net/?id=34358&edit=1