Do not call isatty if it doesn't exist

[mamadou <tobutaz+django@…>]

In source:django/trunk/django/core/management/color.py

    if (sys.platform == 'win32' or sys.platform == 'Pocket PC'
        or sys.platform.startswith('java') or not sys.stdout.isatty()):

Should be replaced by:

    if not (hasattr(sys.stdout, 'isatty') and sys.stdout.isatty()):

Because according to the ​python docs, isatty isn't mandatory to implement.

In practice, isatty isn't implemented when importing django classes from a twistd daemon, hence a crash.

[Gary Wilson]

It seems the java check can be removed because it was added due to Jython not having the isatty method (#5319). It appears that the Windows check was added for the same reason (#1762), but I've got a Windows XP machine here with Python 2.4 that does have an isatty method which returns True. Does Windows support terminal colors? If not, then the win32 check needs to stay.

[mamadou <tobutaz+django@…>]

Patch is good, I'm using it on django trunk, don't let it bitrot.

[Gary Wilson]

(In [7202]) Fixed #6223 -- When determining if terminal supports color, don't call isatty if it doesn't exist, thanks mamadou.