Wrong inference that get_parent_class() always return false

[noemi-salaun]

Bug report

When using get_parent_class($object) on something that may be a subclass, PHPStan assume that it can only return false.

Code snippet that reproduces the problem

class HelloWorld
{	
    public function theMethod(MyInterface $object) {
        if (get_parent_class($object)) {    // <-- ERROR: if condition is always false
            return 1;
        }
    }
}

interface MyInterface {}

https://phpstan.org/r/a374c54d-1422-4c1e-9a34-5005f6668c8c

Expected output

When using an interface or a superclass, PHPStan should not be sure about the return being false, it should keep the type string|false, because the real object may be a subclass of the one typehinted

[mvorisek]

this issue is still present, demo: https://phpstan.org/r/fe18bc9e-c405-4579-a30b-1ed7f55378e8

[phpstan-bot]

@noemi-salaun After the latest push in 1.11.x, PHPStan now reports different result with your code snippet:

@@ @@
-6: If condition is always false.
+No errors

[ondrejmirtes]

Fixed: phpstan/phpstan-src#2336

[github-actions]

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