The list of commits included in a merge commit will (erroneously?) include itself unless the URL used to view the commit includes the full commit hash
This is reproducible with both mercurial and git, and can be seen on the secure.phabricator.com site:
Compare the list of commits here:
This can come across in real life as Remarkup picks up hashes and auto-links them using only the typed hash. I think this is frequently 12 characters of hash for merurial, probably also git.