LayerDatabasePolicyTestCase shouldn't use DummyConfiguration

[James Henstridge]

When running "bin/test -vvm canonical.launchpad.webapp" in devel r8802, I got a failure in test_getPrincipal_for_person_and_account_with_different_ids (from test_publication) in looking up the IWebServiceConfiguration utility.

If instead I run the following, everything passes:

bin/test -vvm canonical.launchpad.webapp -t '!(LayerDatabasePolicyTestCase|TestVhostWebserviceFactory|TestWebServiceRequestTraversal)'

The tests excluded in this second run all subclass from DummyConfigurationTestCase, whose tearDown() unregisters the IWebServiceConfiguration utility. I suspect that this doesn't trigger in a full test suite run due to the test runner re-executing itself at a layer change before the problem tests.

[Francis J. Lacoste (flacoste)]

I think this is a layer problem. Tests using the DummyConfigurationTestCase should not use any layer I think. Otherwise, they will overwrite the normal web service configuration used in Launchpad.