https://travis-ci.org/tornadoweb/tornado/jobs/167252979

Another test failure is reported. > I have setup a 3.6 build on Travis of our project GNS3 and it seem to fail. > https://travis-ci.org/GNS3/gns3-server/builds/167703118

pure Python Future.__iter__ don't use what yield-ed. def __iter__(self): if not self.done(): self._asyncio_future_blocking = True yield self # This tells Task to wait for completion. assert self.done(), "yield from wasn't used with future" return self.result() # May raise too. I felt no-None value is sent by iter.send(val) wasn't make sense. But Tornado did it (maybe, for compatibility to Tornado's generator.) So this patch ignores when non-None value is passed. Additionally, I moved NEWS entry about C Future from "core and builtin" section to "library" section.

Test failure in GNS3 seems not relating to this. It may be fixed via #28492, maybe.

The patch looks good. 2 things: - It appears it also touches Misc/NEWS a bit too much. Please make sure to not to commit that. - I'd also add a comment explaining why we ignore values passed to FI.send() and simply send None. The reason is how Future.__iter__ is designed: class Future: def __iter__(self): if not self.done(): self._asyncio_future_blocking = True yield self # This tells Task to wait for completion. assert self.done(), "yield from wasn't used with future" return self.result() # May raise too. ^-- Future.__iter__ doesn't care about values that are pushed to the generator, it just returns "self.result()".

New changeset b471447352ac by INADA Naoki in branch '3.6': Issue #28430: Fix iterator of C implemented asyncio.Future doesn't https://hg.python.org/cpython/rev/b471447352ac New changeset bd141ec2973a by INADA Naoki in branch 'default': Issue #28430: Fix iterator of C implemented asyncio.Future doesn't https://hg.python.org/cpython/rev/bd141ec2973a

> - It appears it also touches Misc/NEWS a bit too much. Please make sure to not to commit that. I wont to move move this entry from "Core and Builtins" section to "Library" section: - Issue #26081: Added C implementation of asyncio.Future. Original patch by Yury Selivanov. May I do it?

+- Issue #28430: Fix iterator of C implemented asyncio.Future doesn't accept + non-None value is passed to it.send(val). This NEWS entry is not a coherent English sentence. Please revise. I don't understand it well enough to suggest a revision, but would review a replacement.

I'm sorry about my bad English. > Fix iterator of C implemented asyncio.Future This meant: fut = asyncio.Future() # C implemented version of asyncio.Future it = iter(fut) # Iterator of it it.send(42) # raised TypeError before. It was not compatible with Python version of asyncio.Future