[PATCH] Bug #53727 Inconsistent behavior of is_subclass_of with interfaces View as Markdown

Hello,

I have attached a patch to the following bug, but I believe the bug is incorrect...

If is_subclass_of() is used in conjunction with a interface it should always return false because it's not a class, it's an interface.

Test:

interface MyInterface {
const TEST_CONSTANT = true;
}

class ParentClass implements MyInterface { }

class ChildClass extends ParentClass { }

echo (is_subclass_of('ChildClass', 'MyInterface') ? 'true' : 'false') . "\n";
echo (defined('ChildClass::TEST_CONSTANT') ? 'true' : 'false') . "\n";

echo (is_subclass_of('ParentClass', 'MyInterface') ? 'true' : 'false') . "\n";
echo (defined('ParentClass::TEST_CONSTANT') ? 'true' : 'false') . "\n";

Expected result:

false
true
false
true

Actual result:

true
true
false
true