False-positive E1133 (not-an-iterable) for iterable context manager

[tucked]

Steps to reproduce

"""sscce.py"""

class Context:
    def __enter__(self):
        return self
    def __exit__(self, type_, exc, traceback):
        return False

class Iterable(Context):
    def __iter__(self):
        return self
    def __next__(self):
        return self

class Foo(Iterable):
    pass

with Foo() as foo:
    for s in foo:
        print(s)

Note: I built this SSCCE from a real-world error I got using paramiko.SFTPFile:

        with self._sftp.open(local_path, mode='r') as local_file:
            for line in local_file:  # triggers on local_file
                yield line.rstrip()

SFTPFile is like Foo. It inherits from paramiko.BufferedFile which is analogous to Iterable, and BufferedFile inherits from paramiko.util.ClosingContextManager.

Current behavior

sscce.py:19:13: E1133: Non-iterable value foo is used in an iterating context (not-an-iterable)

Expected behavior

(no errors)

pylint --version output

pylint 2.4.3
astroid 2.3.3
Python 3.6.8 (default, Oct  7 2019, 12:59:55)
[GCC 8.3.0]

[PCManticore]

Thank you for the clear example, I can confirm the bug.

[cdce8p]

This issue seems to be fixed when testing with the latest pylint version.
If you still encounter issues, please report back and I'll reopen it.

[tucked]

Yes, I can no longer repro either.
This seems to have been fixed in 2.5.0, though I suspect that the fix was in astroid because:

python3.6 -m venv venv
venv/bin/python -m pip install pylint==2.4.4
venv/bin/pylint sscce.py  # repro
venv/bin/python -m pip install astroid~=2.4.0
venv/bin/pylint sscce.py  # NO repro