Once SynchronousTestCase is ported to Python 3, switch test modules using pyunit back to using it

[itamar]

test_compat, test_versions and test_monkey (after #5896 and #5785 are merged) use pyunit, and in some cases have workarounds for lack of SynchronousTestCase: reimplementing mktemp(), del instead of skip support. Once SynchronousTestCase is ported to Python 3, we should revert these changes.

[itamar]

There's a bunch more relevant modules now. Grepping for "5885" should find them all (or just look through list of test modules in _twistedpython3.py.)

[itamarst]

(In [35752]) Branching to 'synctest-py3-5885'

[itamar]

Ready for review.  http://buildbot.twistedmatrix.com/boxes-supported?branch=/branches/synctest-py3-5885 is running.

1. Also covers #5884.
2. Seems to fix the random test_log errors we were seeing.
3. I had to semi-fix some brokenness in test_log.py to make the tests pass after switching to SynchronousTestCase.

[therve]

1. You removed blank lines in from of test_doubleErrorDoesNotRemoveObserver and test_showwarning, but they should stay.

2. Pyflakes:

   twisted/python/test/test_versions.py:12: 'tempfile' imported but unused
   twisted/python/test/test_utilpy3.py:12: '_PY3' imported but unused
   twisted/test/test_paths.py:11: 'tempfile' imported but unused
   twisted/test/test_compat.py:11: 'tempfile' imported but unused
   

Please merge once fixed.

[itamarst]

(In [35792]) Merge synctest-py3-5885.

Author: itamar Review: therve Fixes: #5884, #5885

Remove some temporary code and use of pyunit that worked around unported trial infrastructure that is now available on Python 3.

[ralphm]

This change affects the initialization of _oldshowwarning in twisted.python.log. Because of it, the replacement for warnings.showwarning in startLoggingWithObserver never happens, and no warnings will be routed to the Twisted Logging System anymore. The following example shows the problem:

import warnings
import sys

from twisted.python import log

# log._oldshowwarning = None
log.startLogging(sys.stdout, setStdout=False)
warnings.warn("Oops", UserWarning)

The warning is printed by the default showwarning implementation (no timestamps, etc.):

2012-10-09 12:09:35+0200 [-] Log opened.
q2.py:8: UserWarning: Oops
  warnings.warn("Oops", UserWarning)

The commented-out line reverts to the correct behavior:

2012-10-09 12:10:04+0200 [-] Log opened.
2012-10-09 12:10:04+0200 [-] q2.py:8: exceptions.UserWarning: Oops

[itamar]

I assume JP re-closed this because the issue was filed on the wrong ticket. I will, in any case, revert and then fix the appropriate code today.

[ralphm]

No, it was because I reopened the issue manually instead of by reverting the change. JP mentioned you'd probably do that anyway. I chose this ticket as the merged branch had this ticket number.

[itamar]

1. Since I didn't do it earlier: thanks so much for reporting this!
2. I guess I shouldn't be assuming ( http://drinkydrink.com/noone.html); I thought it was the log ticket, my bad.