summary: use the new APIs Summary can perform some incoming/outgoing queries (that should be common to the other command with the same needs, but that is another story). We now use the new APIs to do so. The current code behavior is a bit fishy, relying to the fact "default" will be picked as the destination in last resort. I did not altered that, but left various comment to highlight the issue. Differential Revision: https://phab.mercurial-scm.org/D10420