Improve `origin_add` logic
to avoid processing twice the history graph of a revision that was already seen as the head of another origin.
Migrated from D7166 (view on Phabricator)
Staging instance, all changes can be removed at any time
to avoid processing twice the history graph of a revision that was already seen as the head of another origin.
Migrated from D7166 (view on Phabricator)