rename transaction triggers a test failure on Windows7,

[cboos]

Seen in Tim's buildbot:

​http://buildbot.timhatch.com/trac/builders/win7%20py26/builds/62

ERROR: Test for regression of http://trac.edgewall.org/ticket/3833 c
----------------------------------------------------------------------
Traceback (most recent call last):
  File "c:\Users\buildbot\Desktop\tracbb\t35\build\trac\tests\functional\testcases.py", line 93, in runTest
    env.config.save()
  File "c:\Users\buildbot\Desktop\tracbb\t35\build\trac\config.py", line 233, in save
    fileobj.close()
  File "c:\Users\buildbot\Desktop\tracbb\t35\build\trac\util\__init__.py", line 178, in commit
    rename(self._temp, self._path)
  File "c:\Users\buildbot\Desktop\tracbb\t35\build\trac\util\__init__.py", line 113, in rename
    raise ctypes.WinError()
WindowsError: [Error 6701] The requested operation was made in the context of a transaction that is no longer active.

Related to code introduced in r8635.

Gc issue? Timeout issue?

[rblank]

Replying to cboos:

Keywords needrblank added

Very funny :)

Now that I have a Windows 7 VM, I should look into this. A timeout sounds likely, maybe we should set the transaction timeout to a larger value than 1 second. Maybe 5 or 10 seconds.

[rblank]

Unfortunately, I'm not able to reproduce the issue. I tried adding delays at various points during the rename and in the rename test cases, but no joy.

I increased the transaction timeout to 10 seconds anyway in [9244]. Also, the code has changed since then (it doesn't raise a WinError anymore, and tries os.rename() instead), so the issue might have been fixed (or made more unlikely to happen) with that change.