Bug #52428 [NEW]: $this isn't immutable

From: Operating system: all PHP version: 5.3.3 Package: Scripting Engine problem Bug Type: Bug Bug description:$this isn't immutable Description: ------------ As some closed bug-reports and the "PHP Fatal error: Cannot re-assign $this" states, the $this should be read-only/inmutable in PHP5. but with some tricks(variable variables mostly), you can walk-around this constraint. See the Test script. I don't know the importance of this restriction, and with reflection you can shoot you in the leg anyway, so maybe this can be left as is. Test script: --------------- <?php error_reporting(E_ALL); $var = new StdClass(); $var->foo = 'bar'; //$this = $var; // PHP Fatal error: Cannot re-assign $this $GLOBALS['this'] = $var; var_dump($this); $var->foo = 'baz'; $foo = 'this'; $$foo = $var; var_dump($this); foo($this); function foo($this){ //global $this; // PHP Fatal error: Cannot re-assign $this // $this = $GLOBALS['var']; // PHP Fatal error: Cannot re-assign $this var_dump($this); $GLOBALS['this']->foo = 'baw'; $$GLOBALS['foo'] = $GLOBALS['this']; var_dump($this); } Expected result: ---------------- PHP Fatal error: Cannot re-assign $this for every attempt to overwrite $this Actual result: -------------- you can set $this in the global scope through $GLOBALS, with argument in functions, and with variable variables in everywhere. -- Edit bug report at http://bugs.php.net/bug.php?id=52428&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=52428&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=52428&r=trysnapshot53 Try a snapshot (trunk): http://bugs.php.net/fix.php?id=52428&r=trysnapshottrunk Fixed in SVN: http://bugs.php.net/fix.php?id=52428&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=52428&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=52428&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=52428&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=52428&r=needscript Try newer version: http://bugs.php.net/fix.php?id=52428&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=52428&r=support Expected behavior: http://bugs.php.net/fix.php?id=52428&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=52428&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=52428&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=52428&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=52428&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=52428&r=dst IIS Stability: http://bugs.php.net/fix.php?id=52428&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=52428&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=52428&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=52428&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=52428&r=mysqlcfg