Bug #79022 [Opn->Csd]: class_exists returns True for classes that are not ready to be used

Edit report at https://bugs.php.net/bug.php?id=79022&edit=1 ID: 79022 Updated by: laruence@php.net Reported by: mech at themech dot net Summary: class_exists returns True for classes that are not ready to be used -Status: Open +Status: Closed Type: Bug Package: *General Issues Operating System: Linux PHP Version: 7.4.1 Block user comment: N Private report: N New Comment: Automatic comment on behalf of laruence@gmail.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=153c9cc346bae927394d3ce1378f77fb7c1e1be3 Log: Fixed bug #79022 (class_exists returns True for classes that are not ready to be used) Previous Comments: ------------------------------------------------------------------------ [2019-12-23 22:24:13] mech at themech dot net Description: ------------ I noticed this issue while debugging Koseven framework with PHP 7.4. It is related to class autoloading. Imagine there is an autoloader function registered with the following code inside: if (class_exists('B', False)) { new B(); } If class B extends some other class A and autoloading function is called to load class A then class_exists('B', false) returns true even if B is not "fully loaded" as its parent class A is still to be loaded. So under PHP 7.4 the "new B()" is being executed and throws "Fatal error: Uncaught Error: Class 'B' not found". The same code works with PHP 7.3 Test script: --------------- <?php // classes/Foo.php: class Foo extends Bar {} // classes/Bar.php: class Bar {} function my_autoloader($class) { if (class_exists('Foo', False)) { new Foo(); } if ($class == 'Foo' or $class == 'Bar') { include "classes/$class.php"; } } spl_autoload_register('my_autoloader'); new Foo(); echo "end" Expected result: ---------------- class_exists should not return true for the class that does not exist yet.atal Actual result: -------------- Fatal error, class not found. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79022&edit=1