The merge-base between @$parents and $merge_tip may have been reached
through a merge commit. This means that some commits that are ancestors
of @$parents will not be ancestors of $merge_base. The mergeinfo
property will not list commits that are ancestors of @$parents, so we
need to explicitly exclude them.
[ew: squashed and cleaned up test case from Steven]
Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>
