test-rebase: add another test for rebase with multiple roots This test the case when a Merge is dropped.

update: update to current bookmark if it moved out from under us (issue3682) If the current bookmark (the one listed in .hg/bookmarks.current) doesn't point to a parent of the working directory, e.g. if it was moved by a pull, use that as the update target instead of the tipmost descendent. A small predicate is (finally) added to the bookmarks module to check whether the current bookmark is also active.

test-bookmarks-pushpull.t: don't set bookmark active unnecessarily The test in question doesn't have anything to do with having an active bookmark. This change makes the test change the two bookmarks it affects without making them active. It clears the way for adding a test for updating to an active bookmark that moved out from under us.