From: php dot bugs at daverandom dot com Operating system: Any PHP version: Irrelevant Package: Scripting Engine problem Bug Type: Bug Bug description:Various ways to reassign this
Description: ------------ The engine prevents userland code from directly reassigning $this with a compile time error, but it does not prevent a number of other mechanisms. The following are all possible: unset($this); // ... public function test() { ${'th'.'is'} = 'foo'; } // ... public function test() { $foo = 'this'; $$foo = 'foo'; } // ... function ref(&$arg) { $arg = 'foo'; } public function test() { ref($this); } Test script: --------------- <?php function ref(&$arg) { $arg = 'foo'; } class ThisReassignments { public function test1() { var_dump($this); ${'th'.'is'} = 'foo'; var_dump($this); } public function test2() { var_dump($this); $foo = 'this'; $$foo = 'foo';; var_dump($this); } public function test3() { var_dump($this); ref($this); var_dump($this); } } (new ThisReassignments)->test1(); (new ThisReassignments)->test2(); (new ThisReassignments)->test3(); // NB: unset() causes a segmentation fault and doesn't *really* work, but it should emit a meaningful error Expected result: ---------------- Fatal error with a meaningful error message in all cases Actual result: -------------- object(ThisReassignments)#1 (0) { } string(3) "foo" object(ThisReassignments)#1 (0) { } string(3) "foo" object(ThisReassignments)#1 (0) { } string(3) "foo" -- Edit bug report at https://bugs.php.net/bug.php?id=64741&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=64741&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=64741&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=64741&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=64741&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=64741&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=64741&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=64741&r=needscript Try newer version: https://bugs.php.net/fix.php?id=64741&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=64741&r=support Expected behavior: https://bugs.php.net/fix.php?id=64741&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=64741&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=64741&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=64741&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=64741&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=64741&r=dst IIS Stability: https://bugs.php.net/fix.php?id=64741&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=64741&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=64741&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=64741&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=64741&r=mysqlcfg