Use ancestors(x) instead of 0::x in Mercurial history queries

Summary: If `0` isn't an ancestor of the current branch, the `0::x` construction fails. This is uncommon, but not wildly unreasonable. The `ancestors()` construction is simpler anyway.

Test Plan: Viewed some `hg` repos locally (change history, file history) without anything suspicious cropping up.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7844

src/applications/diffusion/conduit/ConduitAPI_diffusion_historyquery_Method.php

@@ -125,7 +125,7 @@ extends ConduitAPI_diffusion_abstractquery_Method {
       '{node};{parents}\\n',
       ($offset + $limit), // No '--skip' in Mercurial.
       $branch_arg,
-      hgsprintf('reverse(%s::%s)', '0', $commit_hash),
+      hgsprintf('reverse(ancestors(%s))', $commit_hash),
       $path_arg);
 
     $stdout = PhabricatorRepository::filterMercurialDebugOutput($stdout);

src/applications/diffusion/conduit/ConduitAPI_diffusion_lastmodifiedquery_Method.php

@@ -87,7 +87,7 @@ final class ConduitAPI_diffusion_lastmodifiedquery_Method
     list($hash) = $repository->execxLocalCommand(
       'log --template %s --limit 1 --removed --rev %s -- %s',
       '{node}',
-      hgsprintf('reverse(%s::%s)', '0', $drequest->getCommit()),
+      hgsprintf('reverse(ancestors(%s))',  $drequest->getCommit()),
       nonempty(ltrim($path, '/'), '.'));
 
     return $this->loadDataFromHash($hash);