copies-tests: update the analysis of the BD/DB cases After thinking more about it, the current change in output between the two merges is not due to an ambiguity, it is introduce by a bug in merge/commit that record a wrong file history. Fixing the bug should fix the output. In the meantime, we have a wrong behavior. In practice the bug is not in the merge code (who does the right things), but in the commit code (who get confused when recording the new file revision). Differential Revision: https://phab.mercurial-scm.org/D8237