The Popen.communicate() method ignores broken pipe error when writing to stdin. I propose to modify Popen.__exit__() to do the same in Python 3.5.

Attached patch implements this suggestion and document it. I added this paragraph to Popen doc:

"The context manager ignores broken pipe errors when closing the process’s stdin: call explicitly proc.stdin.flush() and proc.stdin.close() to get broken pipe errors."

So it's still possible to get broken pipe errors if you need them.

Do you know applications or libraries which rely on broken pipe errors and do something different than just ignoring them?

I prefer to leave Python 3.4 unchanged to avoid subtle behaviour changes in minor Python releases.

See also:

- issue #21619 which modified Popen.__exit__() to call wait() even if stdin.close() raised an exception
- issue #19612 which modified communicate() to handle EINVAL on stdin.write() on Windows