Message 206177 - Python tracker

This seems to break BaseTestSuite.countTestCases when invoked after the TestSuite has been run:
  ...
  File "Lib/unittest/suite.py", line 42, in countTestCases
    cases += test.countTestCases()
AttributeError: 'NoneType' object has no attribute 'countTestCases'

Attached patch attempts to fix it.