Fix Mercurial "Last Modified" query

Summary:
To determine when a file was last modified, we currently run `hg log ... -b branch ... file`. However, this is incorrect, because Mercurial does not interpret "-b x" as "all ancestors of the commit named x" like Git does, and we don't care about where the modification happened anyway (we always have a resolved commit as a starting point). I think this got copy-pasta'd from the History query.

Instead, drop the branch-specific qualifier and find the last modification, period.

Test Plan: Mercurial commit views of commits not on the repository's default branch are no longer broken.

Reviewers: DurhamGoode, vrana, chad

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D5146

src/applications/diffusion/query/lastmodified/DiffusionMercurialLastModifiedQuery.php

@@ -9,11 +9,9 @@ final class DiffusionMercurialLastModifiedQuery
 
     $path = $drequest->getPath();
 
-    // TODO: Share some of this with History query.
     list($hash) = $repository->execxLocalCommand(
-      'log --template %s --limit 1 -b %s --rev %s:0 -- %s',
+      'log --template %s --limit 1 --rev %s:0 -- %s',
       '{node}',
-      $drequest->getBranch(),
       $drequest->getCommit(),
       nonempty(ltrim($path, '/'), '.'));