Bug #75831 [Com]: Coalesce operator ?? never uses the default isset() handler

Edit report at https://bugs.php.net/bug.php?id=75831&edit=1 ID: 75831 Comment by: michael dot vorisek at email dot cz Reported by: nobots dot nospam at example dot org Summary: Coalesce operator ?? never uses the default isset() handler Status: Assigned Type: Bug Package: *General Issues PHP Version: 7.2.1 Assigned To: nikic Block user comment: N Private report: N New Comment: Is this expected to be fixed soon - and backported or at least in PHP 8.0? Previous Comments: ------------------------------------------------------------------------ [2019-01-25 16:24:46] nikic@php.net I agree with the original reporter that this is a bug. $foo->bar ?? $baz should behave the same way as isset($foo->bar) ? $foo->bar : $baz, and in this case it does not. https://3v4l.org/UI13h ------------------------------------------------------------------------ [2018-01-21 17:23:41] timok at ya dot ru Imho, this is not a bug, but quite expected and correct behavior. You define a handler to get inaccessible properties (__get), then it is called whenever you try to access an inaccessible property, including NULL coalesce operator. If object has a property check method (__isset), then it is called before __get. So, the code var_dump($bar->foo ?? "qux"); // works now, without errors... - is equivalent to the following: var_dump(isset($bar->foo) ? $bar->foo : "qux"); // also works without errors: https://3v4l.org/4EPXm - http://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.coalesce - https://wiki.php.net/rfc/isset_ternary ------------------------------------------------------------------------ [2018-01-17 11:44:22] nobots dot nospam at example dot org Description: ------------ The coalesce operator calls __get(prop) directly without testing isset($obj->prop) first. It only calls isset($obj->prop) if there is an explicit user-defined __isset() handler. Test script: --------------- class Bar{ function __get($a){ throw new Error("no prop error\n"); } } $bar = new Bar; try{ var_dump($bar->foo ?? "qux"); // error... } catch(Throwable $e){ echo $e->getMessage(); } var_dump(isset($bar->foo)); // ...but this works fine Expected result: ---------------- class Bar{ function __isset($a){ return isset($this->{$a}); // I shouldn't be forced to implement this, // since it looks exactly like the default isset() handler } function __get($a){ throw new Error("no prop error\n"); } } $bar = new Bar; var_dump($bar->foo ?? "qux"); // works now, without errors... ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75831&edit=1