class decorators changing class type cause wrong errors

[ojii]

from typing import Type

class A:
    pass

def deco(cls) -> Type[A]:
    return A

@deco
class B:
    pass

def func(cls: Type[A]):
    assert cls is A

func(B)

Running mypy on that code causes this error:

hoge.py:16: error: Argument 1 to "func" has incompatible type "B"; expected Type[A]

mypy version is mypy 0.511-88e8ef28be2465d1693ace4d39cd422987a97220-dirty.

I would expect it to correctly detect the type of B.

[JelleZijlstra]

This is a duplicate of #3135.

[ilevkivskyi]

Yes, this is a duplicate of a more "broad" bug - mypy ignores class decorators altogether.