Deprecate twisted.mail.protocols.SSLContextFactory

[exarkun]

SSLContextFactory provides no particular value over something like twisted.internet.ssl.DefaultOpenSSLContextFactory (in fact, less, since it allows SSLv2). We should change our internal usage of the former (probably to the latter) and deprecate the former.

[exarkun]

Thanks for working on this, moijes12. It looks like your patch does a good job addressing the second half of this ticket, but I don't think it covers the first half.

Twisted itself should never trigger its own deprecation warnings. Therefore, when deprecating a Twisted API, we also need to remove all usages of that API within Twisted itself. (You may have noticed that we don't always do a good job of this, by the number of warnings emitted when running the test suite. This is an area where we need to improve.)

Apart from that:

1. make sure you wrap lines at 80 columns or before
2. name tests like test_foo instead of testFoo
3. Don't start test method docstrings with "Test ..."

Thanks again!

[moijes12]

The tests for pop3sBackwardCompatibilty now use DefaultOpenSSLContextFactory. For this, a copy of server.pem has been placed in twisted/mail/test. All other changes that were supplied in the first patch are in here too. So, now, SSLContextFactory has been deprecated and its usage has been replaced with DefaultOpenSSLContextFactory.

[exarkun]

(In [34763]) Branching to 'deprecate-redundant-ssl-context-4963'

[exarkun]

(In [34765]) Just use the server.pem from the source tree, no need to copy it to a temporary file first.

refs #4963

[exarkun]

(In [34766]) - Rewrite the test method docstring in the conventional style - Remove the call of SSLContextFactory, attribute access is enough - wrap the long warning assertion line to < 80 columns

refs #4963

[exarkun]

(In [34767]) - Remove trailing whitespace - Wrap long deprecation line to < 80 columns

refs #4963

[exarkun]

Thanks! I made a few small changes to the patch, mostly whitespace. Otherwise it looks good, so I'll apply it. Thanks again!

[exarkun]

(In [34769]) Merge deprecate-redundant-ssl-context-4963

Author: moijes12 Reviewer: exarkun Fixes: #4963

Deprecate twisted.mail.protocols.SSLContextFactory.