Instance of 'list' has no 'get_name' member regression in astroid 2.5

[chrisburr]

Steps to reproduce

Make a file containing:

class A:
    def __init__(self):
        self._data = []

    def add(self, value):
        self._data += [value]

    def exists(self, name):
        for i in self._data:
            if i.get_name() == name:
                return True
        return False


class B:
    name = "my-name"

    def get_name(self):
        return self.name


if __name__ == "__main__":
    j = A()
    j.add(B())
    print(j.exists("my-name"), j.exists("my-name2"))

This runs successfully but linting with pylint gives the error:

$ pylint reproducer.py --disable=invalid-name,missing-module-docstring,missing-function-docstring,missing-class-docstring,too-few-public-methods
************* Module reproducer
reproducer.py:10:15: E1101: Instance of 'list' has no 'get_name' member (no-member)

-----------------------------------
Your code has been rated at 7.22/10

Current behavior

Pylint fails to realise that items within A._data are not lists. This is a new regression in astroid 2.5 and downgrading to 2.4.2 while changing no other packages causes the false positive to go away.

Expected behavior

No error message.

[chrisburr]

I realised this might actually be the same thing as the other recent issues (#895 and #899) so I tried running with #901 locally and it fixes this issue. Sorry for the duplicated report!

[hippo91]

@chrisburr thanks for your report. It is not useless because it confirms that we definitely needs #901