Fix an issue where a GROUP BY was missing when a query matched a revision using multiple hashes
Ref T13581. If you query for revisions by hash and provide multiple hashes (A, B) which match a single revision (e.g., older and newer diffs for that revision), the query omits a GROUP BY clause but should contain one.
Add a GROUP BY clause in this case.
With a working copy that has multiple hashes corresponding to a single revision, ran arc branches before and after the change. Before, got this error:
[2020-09-15 17:02:07] EXCEPTION: (ConduitClientException) ERR-CONDUIT-CORE: Rows passed to "loadAllFromArray(...)" include two or more rows with the same ID ("130"). Rows must have unique IDs. An underlying query may be missing a GROUP BY. at [<arcanist>/src/conduit/ConduitFuture.php:65]
After, clean execution.
Maniphest Tasks: T13581
Differential Revision: https://secure.phabricator.com/D21462