gh-113280: Always close socket if SSLSocket creation failed

[serhiy-storchaka]

• Issue: ResourceWarning in ssl.SSLSocket connected detection #113280

[graingert]

I think it would be better to call sock.gettimeout() and sock.detach() outside the try/catch - as if either of those raise you could get a double close

        sock_timeout = sock.gettimeout()
        kwargs = dict(
            family=sock.family, type=sock.type, proto=sock.proto,
            fileno=sock.detatch()
        )
        self = cls.__new__(cls, **kwargs)
        super(SSLSocket, self).__init__(**kwargs)
        try:
            self._context = context
            ...

[serhiy-storchaka]

But what if __new__ or __init__ raise?

[graingert]

Then they should be responsible for closing the passed in fileno

[serhiy-storchaka]

They are not. If you pass a fileno, you are responsible (in this case it is the responsibility of sock until detach() is called).

[serhiy-storchaka]

I added tests, although the original case reported in the issue is not covered by tests. But I added tests for two cases in which an explicit close() was already called and which are now merged with a more general solution. And a new test for incorrect hostname, it emits a resource warning without this fix.

[miss-islington-app]

Thanks @serhiy-storchaka for the PR 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[bedevere-app]

GH-114995 is a backport of this pull request to the 3.12 branch.

[bedevere-app]

GH-114996 is a backport of this pull request to the 3.11 branch.