test breaks if existing mailman.cfg is found

The test program reports an error if it detects an existing mailman.cfg:

Failure in test test_current_working_directory (mailman.tests.test_configfile.TestConfigFileSearch)
Traceback (most recent call last):
  File "/usr/lib/python2.6/unittest.py", line 279, in run
    testMethod()
  File "/root/mailman/src/mailman/tests/test_configfile.py", line 107, in test_current_working_directory
    self.assertEqual(found, config_file)
  File "/usr/lib/python2.6/unittest.py", line 350, in failUnlessEqual
    (msg or '%r != %r' % (first, second))
AssertionError: '/etc/mailman.cfg' != u'/tmp/tmpVfAIyB/home/alex/mailman/hacking/mailman.cfg'

I believe it should not do this. It should either silently ignore the difference or use the test mailman.cfg or ... but not break.