py3k: child process don't inherit stdout / stderr on Windows

[vstinner]

BPO	8780
Nosy	@gpshead, @pitrou, @vstinner, @briancurtin
Files	subprocess_windows.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/vstinner'
closed_at = <Date 2010-05-21.20:40:56.201>
created_at = <Date 2010-05-21.12:37:55.531>
labels = ['interpreter-core', 'library', 'OS-windows']
title = "py3k: child process don't inherit stdout / stderr on Windows"
updated_at = <Date 2010-05-21.20:40:56.199>
user = 'https://github.com/vstinner'

bugs.python.org fields:

activity = <Date 2010-05-21.20:40:56.199>
actor = 'vstinner'
assignee = 'vstinner'
closed = True
closed_date = <Date 2010-05-21.20:40:56.201>
closer = 'vstinner'
components = ['Interpreter Core', 'Library (Lib)', 'Windows']
creation = <Date 2010-05-21.12:37:55.531>
creator = 'vstinner'
dependencies = []
files = ['17430']
hgrepos = []
issue_num = 8780
keywords = ['patch']
message_count = 8.0
messages = ['106232', '106233', '106234', '106237', '106238', '106244', '106246', '106263']
nosy_count = 4.0
nosy_names = ['gregory.p.smith', 'pitrou', 'vstinner', 'brian.curtin']
pr_nums = []
priority = 'critical'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue8780'
versions = ['Python 3.2']

[vstinner]

The following code works on 2.6, 2.7 (trunk), 3.1, but not on py3k.

import subprocess, sys
subprocess.call([sys.executable, '-c', 'print("Hello World!")'])

On py3k, sys.stdout and sys.stderr are equal to... None.

I hope that it's a problem with my setup.

[vstinner]

("doesn't work" means that the example doesn't print anything)

[pitrou]

It's just under Windows, right?

[vstinner]

It's just under Windows, right?

It works on Linux. I suppose that the issue is specific to Windows.

[vstinner]

Recent change of subprocess in py3k, I don't know if it's related: r78946.

[vstinner]

Ok, it *is* a regression introduced by r78946. Attached patch fixes the issue and adds a regression test.

Add also the author of r78946 to the nosy list :-)

[briancurtin]

Looks fine to me.

The first line of the test comment has "if" instead of "is" but you could fix that on checkin.

[vstinner]

Fixed by r81403 (py3k).

Even if the issue is a regression specific to 3.x, I backported the new test in 3.1: r81408.