Proposed patch fixes miscellaneous errors in asyncio speedup module. It is hard to enumerate they all, but they are mostly NULL dereferencing, reference leaks, and handling exceptions in corner cases.

Adding INADA, he is a co-author/reviewer of that code.

Huge thanks, Serhiy, btw.

"reference leaks" oh? our Refleaks buildbots didn't catch them. Do your new tests reproduce the bugs, to make sure that we don't leak anymore?

> "reference leaks" oh? our Refleaks buildbots didn't catch them. The test suite for Tasks and Futures is pretty extensive, but it obviously doesn't cover some obscure use cases. +1 to make sure that any refleak that was discovered should have a new regression test for it.

They are occurred in very obscure cases like calling __init__ multiple times. The patch doesn't contain tests for them.

 New changeset bca4939d806170c3ca5d05f23710d11a8f1669cf by Serhiy Storchaka in branch 'master': bpo-31185: Fixed miscellaneous errors in asyncio speedup module. (#3076) https://github.com/python/cpython/commit/bca4939d806170c3ca5d05f23710d11a8f1669cf 

 New changeset 98bbeb78e06d5756491705920e72f9721850c727 by Serhiy Storchaka in branch '3.6': bpo-31185: Fixed miscellaneous errors in asyncio speedup module. (#3076) (#3269) https://github.com/python/cpython/commit/98bbeb78e06d5756491705920e72f9721850c727 

FYI, there is a missing Py_DECREF from this change: https://bugs.python.org/issue40559 (though it's an obscure code path as mentioned elsewhere in these comments)