False positive E1111 when overriding an inherited method

[exquo]

Steps to reproduce

# pylint: disable=no-self-use

class A:
    def f(self):
        return 42


class B(A):
    def __init__(self):
        self.a = A()
        result = self.a.f()
        print(result)

    def f(self):
        pass


res = B().a.f()

Current behavior

$ pylint -E assignment_from_no_return.py
************* Module assignment_from_no_return
assignment_from_no_return.py:11:8: E1111: Assigning result of a function call, where the function has no return (assignment-from-no-return)
assignment_from_no_return.py:18:0: E1111: Assigning result of a function call, where the function has no return (assignment-from-no-return)

Expected behavior

No errors.

pylint --version output

pylint 2.7.2
astroid 2.5.1
Python 3.7.3 (default, Jul 25 2020, 13:03:44)
[GCC 8.3.0]

Additional info

This happens only for very particular conditions:

• Child class has an attribute which is an instance of the parent class
  and
• Child class overrides parent's method, which does not return, with a method that does return

In other words, there is no error reported if:

• a is not an attribute of B (self.a changed to a)
  or
• B does not inherit from A (class B(object): ...)

Also, if a third subclass is defined that overrides f again, it does not get this error:

class C(B):
    def __init__(self):
        self.a = A()
        self.b = B()
        res = self.a.f()
        res = self.b.a.f()
    def f(self):
        return -42

Somewhat related:
pylint-dev/astroid#1683 (latest defined method is considered)
#1123 (method overriden on object's instance)
#3218 (the "opposite" of this: the child's method returns, the parent's does not)

P.S. Thanks for maintaining pylint!

[Pierre-Sassoulas]

Thank you for opening the issue, I can reproduce this.