Bug #61526 [Opn->Nab]: is_subclass_of(string, string, false) always returns false

Edit report at https://bugs.php.net/bug.php?id=61526&edit=1 ID: 61526 Updated by: stas@php.net Reported by: gtisza at gmail dot com Summary: is_subclass_of(string, string, false) always returns false -Status: Open +Status: Not a bug Type: Bug Package: Class/Object related Operating System: Debian PHP Version: 5.3.10 Block user comment: N Private report: N New Comment: Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php This is expected behavior. Please see bug #55475 for more info. Previous Comments: ------------------------------------------------------------------------ [2012-03-29 02:37:04] yohgaki@php.net The same behavior in PHP 5.4.1RC. Is this a doc problem or bug in PHP? From http://php.net/manual/en/function.is-subclass-of.php ---- allow_string Whether to call autoloader if the class doesn't exist. ---- ---- 5.3.9 Added allow_string parameter 5.0.3 You may also specify the object parameter as a string (the name of the class) ---- I'm not sure, but is this a bug introduced by is_a() fix? I didn't follow the discussion, so I hope someone could address this issue. BTW, correct PoC would be following code. <?php class Super {} class Sub extends Super {} var_dump(is_subclass_of('Sub', 'Super')); // true var_dump(is_subclass_of('Sub', 'Super', true)); // true var_dump(is_subclass_of('Sub', 'Super', false)); // false ?> ------------------------------------------------------------------------ [2012-03-27 09:46:04] gtisza at gmail dot com Description: ------------ According to the documentation ( http://php.net/manual/en/function.is-subclass-of.php ) the third parameter of is_subclass_of decides "Whether to call autoloader if the class doesn't exist." That means that is_subclass_of('class1', 'class2', false) should - return true if class1 is loaded and a subclass of class2 - return false if class1 is loaded but not a subclass of class2 - return false if class1 is not loaded What actually happens is that it always returns false, no matter what. The naming of the parameter - "$allow_string" - suggests this is somewhat intentional, but it is a completely unintuitive and unhelpful behavior, which makes the option completely useless: is_subclass_of with $allow_string set to false becomes worthless if the first argument is a string, and if it is an object, the third parameter is pointless again as the class must have been loaded already. Test script: --------------- class Super {} class Sub extends Super {} var_dump(is_subclass_of('Sub', 'Super')); // true var_dump(is_subclass_of('Sub', 'Super'), false); // should be true but false ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=61526&edit=1