Descriptor exit_policy can raise TypeError?
In sbws we got this traceback:
File "/usr/lib/python3/dist-packages/sbws/lib/relaylist.py", line 117, in can_exit_to_port if not self.exit_policy: File "/usr/lib/python3/dist-packages/stem/exit_policy.py", line 512, in __len__ # noqa return len(self._get_rules()) File "/usr/lib/python3/dist-packages/stem/exit_policy.py", line 464, in _get_rules # noqa for rule in decompressed_rules: TypeError: 'NoneType' object is not iterable
I'm a bit confused on what triggers that, because looking at stem code, it does not seem that
_get_rules, but this seems to happen when just getting the exit_policy attribute in sbws: https://github.com/torproject/sbws/blob/master/sbws/lib/relaylist.py#L92.
In the moment _get_rules is call, this might happen because it is not check that
_input_rules is not None: https://github.com/torproject/stem/blob/master/stem/exit_policy.py#L462?
_input_rules be assigned  instead of None in https://github.com/torproject/stem/blob/master/stem/exit_policy.py#L507?