Mercurial - differences merging repository A->B vs B->A?

Question

Given repository A and repository B (created off a clone of changeset A2):

A1 - A2 - A3 - A4 - A5
        \
          B3 - B4

Say we wanted to merge these two repositories together. Is there any difference if we merged repo B into repo A versus merging repo A into repo B?

The only diff I can think of is the merge tool local/base arguments would be reversed depending on which option you chose. Are there any other differences to be aware of?

Answer 1

Generally merges are symmetric, with a few exceptions:

• If the merged heads are from different named branches, the order is important. The merge revision will be on the first parent's branch.
• Starting with Mercurial 1.8.4 the same applies to bookmarks, i.e. only the bookmark
  of the first parent will move forward to the merge revision.
• The order of the merge revision's parents in log and diff views is different, but that doest not have any noteworthy practical implications (from my experience).