There is a problem demonstrated by merge_tests.py test 33, "merge a replacement
of a directory". This problem was discussed on the dev list without conclusion
in the conversation "deleted-with-history [sic] after merge" at
This problem only shows up now that commit refuses to delete an object that has
already been deleted in the repository, which was the subject of issue #3156,
"Delete should conflict with delete (at the repos level)". See that issue for
further history and comments on this problem.