ID: 48460 Updated by: j...@php.net Reported By: ben at last dot fm -Status: Open +Status: Feedback Bug Type: Scripting Engine problem Operating System: Linux PHP Version: 5.2.9 New Comment:
Please try using this snapshot: http://snaps.php.net/php5.3-latest.tar.gz For Windows: http://windows.php.net/snapshots/ Previous Comments: ------------------------------------------------------------------------ [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] col...@php.net 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. ------------------------------------------------------------------------ [2009-06-03 13:32:35] ben at last dot fm More minimal test case: <?php class A { var $p; } $a = new A; $a->list = 1; $b = clone $a; $link =& $a->p; unset($link); $c = clone $a; $link =& $a->p; $d = clone $a; unset($link); $e = clone $a; $b->p = 2; $c->p = 3; $d->p = 4; $e->p = 5; echo "$a->p\n$b->p\n$c->p\n$d->p\n$e->p\n"; ------------------------------------------------------------------------ [2009-06-03 13:29:02] ben at last dot fm Description: ------------ If you create a reference to a property of an object, then clone the object, the reference will become bi-directional and the property will no longer behave like a property. This does not happen if you create, then destroy, the reference BEFORE cloning. This persists even if you unset the reference AFTER cloning. Reproduce code: --------------- <?php class A { var $list; } $a = new A; $a->list = array( 1, 1, 1, 1, 1 ); $b = clone $a; $link =& $a->list; unset($link); $c = clone $a; $link =& $a->list; $d = clone $a; unset($link); $e = clone $a; $b->list = array(2,2,2,2,2); $c->list = array(3,3,3,3,3); $d->list = array(4,4,4,4,4); $e->list = array(5,5,5,5,5); echo "$a\n$b\n$c\n$d\n$e\n"; Expected result: ---------------- {1} {2} {3} {4} {5} Actual result: -------------- {5} {2} {3} {5} {5} ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=48460&edit=1
