#43505 [NEW]: Assign by reference bug

From: vidmich at gmail dot com Operating system: Windows PHP version: 5.2.5 PHP Bug Type: Scripting Engine problem Bug description: Assign by reference bug Description: ------------ Recently I came across a bug in my work with Zend Framework linked with Smarty. In my investigation I found strange feature of PHP about creation new element in array if we assign by ref some undefined index from it (ZEND_FETCH_DIM_W implementation). For example: $a = array(); $b =& $a['test’]; After this code array $a will get new element indexed as “test” and pointing to NULL. This is strange and I didn’t find documentation for this, but this is rather a feature than a bug. But I found situation in which above code return _different_ result, which is really bad and breaks Smarty plugins loading. This situation happened when we return undefined field in count function in Countable object. For example class Test implements Countable { public function count() { return $this->test; } } In my opinion calling count on such object (object of class Test) break global variable in Zend Engine named “uninitialized_zval” and as a result new created elements point to int(0) instead of NULL Please make this feature more predictable Reproduce code: --------------- <?php class Test implements Countable { public function count() { return $this->some; } } $obj = new Test(); $a = array(); $b =& $a['test']; var_dump($a); $t = count($obj); $a = array(); $b =& $a['test']; var_dump($a); Expected result: ---------------- array(1) { ["test"]=> &NULL } array(1) { ["test"]=> &NULL } Actual result: -------------- array(1) { ["test"]=> &NULL } array(1) { ["test"]=> &int(0) } -- Edit bug report at http://bugs.php.net/?id=43505&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=43505&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=43505&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=43505&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=43505&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=43505&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=43505&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=43505&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=43505&r=needscript Try newer version: http://bugs.php.net/fix.php?id=43505&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=43505&r=support Expected behavior: http://bugs.php.net/fix.php?id=43505&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=43505&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=43505&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=43505&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=43505&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=43505&r=dst IIS Stability: http://bugs.php.net/fix.php?id=43505&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=43505&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=43505&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=43505&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=43505&r=mysqlcfg