Req #44552 [Opn]: $this can be overwritten by setting a reference

Edit report at http://bugs.php.net/bug.php?id=44552&edit=1 ID: 44552 Updated by: johannes@php.net Reported by: andre at webkr dot de Summary: $this can be overwritten by setting a reference Status: Open Type: Feature/Change Request -Package: Feature/Change Request +Package: *General Issues Operating System: Tested on Windows and Linux PHP Version: 5.2.5 Block user comment: N Private report: N New Comment: We can't prevent people from shooting in their feet. We can make it a bit harder but not fully prevent it Previous Comments: ------------------------------------------------------------------------ [2008-03-27 15:38:31] andre at webkr dot de Description: ------------ Usually $this cannot be set. But by creating a reference to $this it can. In the example the reference is created by the =& operator. The problem is also valid when passing $this to a function by reference. I think an error should be generated because both $this = 1 and $this =& $x do generate an error. Reproduce code: --------------- class testclass { function foo() { var_dump($this); // object(testclass)#1 (0) { } $this->bar(); var_dump($this); // object(testclass)#1 (0) { } } function bar() { $a =& $this; $a = 1; var_dump($this); // int(1) } } $b = new testclass; $b->foo(); Expected result: ---------------- Fatal error: Cannot re-assign $this in eval()'d code on line 12 Actual result: -------------- object(testclass)#1 (0) { } int(1) object(testclass)#1 (0) { } ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=44552&edit=1