clone: check update rev for being True In 30be3aeb5344, there was an attempt to fallback to looking up the update revision assuming it was always a rev but the documentation states: True means update to default rev, anything else is treated as a revision Therefore, we should only fallback to looking up the update rev if it is not True. This bug was found in hg-git and I couldn't think of a test that does this in pure Mercurial since the source repository is checked for the revision as well (and therefore gracefully falls back).