Fixed compatibility with twisted 17+

[kmike]

I've replaced try/except with explicit version checks and ported code to be compatible with Twisted 17+. This should fix #2555.

For the record, issue was caused by https://twistedmatrix.com/trac/ticket/8916.

Also, we no longer support Ubuntu 12.04, so its tox environment is replaced with Ubuntu 14.04 environment (we still don't run it on Travis though).

[redapple]

Looks good to me. Thanks @kmike! Le 13 févr. 2017 4:08 PM, "Mikhail Korobov" <notifications@github.com> a écrit :

…

I've replaced try/except with explicit version checks and ported code to be compatible with Twisted 17+. This should fix #2555 <#2555>. Also, we no longer support Ubuntu 12.04, so its tox environment is replaced with Ubuntu 14.04 environment (we still don't run it on Travis though). ------------------------------ You can view, comment on, or merge this pull request online at: #2558 Commit Summary - TST replace Ubuntu 12.04 tox environment with 14.04 - fixed tls in Twisted 17+ File Changes - *M* scrapy/core/downloader/tls.py <https://github.com/scrapy/scrapy/pull/2558/files#diff-0> (28) - *M* tox.ini <https://github.com/scrapy/scrapy/pull/2558/files#diff-1> (12) Patch Links: - https://github.com/scrapy/scrapy/pull/2558.patch - https://github.com/scrapy/scrapy/pull/2558.diff — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2558>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA2GGFZTOL41u-UgT5pBeK6n5APpmZGmks5rcHH1gaJpZM4L_UFR> .

[pawelmhm]

should we add more tests for https so that potential problems will be detected easier? Seems like our test suite passed ok with Twisted 17 so apparently our tests are not covering situation that occurred. I understand unit testing TLS bugs is probably not easy, but maybe we could find some way.