If "branch" is provided to "diffusion.branchquery", use it as the "<pattern>" argument to "git branch --contains ..."

Summary:
Ref T13151. See PHI720. If you want to test if commit X appears on specific branch Y, `git branch --contains X -- Y` is faster than (effectively) `git branch --contains X | grep Y`.

Since this call has a "branch" parameter anyway, use it as the pattern argument if provided.

Test Plan:
  - Called the API method with no parameters, got all branches.
  - Called the API method with `master`, got just master.
  - Called the API method with `maste*`, got master. This behavior is not officially supported and may change in the future.
  - Viewed a commit, still saw all branches.
    - Grepped for `diffusion.branchquery` and verified that no remaining callsites pass a default "branch" parameter.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13151

Differential Revision: https://secure.phabricator.com/D19499

src/applications/diffusion/conduit/DiffusionBranchQueryConduitAPIMethod.php

@@ -30,18 +30,31 @@ final class DiffusionBranchQueryConduitAPIMethod
 
     $contains = $request->getValue('contains');
     if (strlen($contains)) {
+
+      // See PHI720. If the standard "branch" field is provided, use it
+      // as the "pattern" argument to "git branch ..." to let callers test
+      // for reachability from a particular branch head.
+      $pattern = $request->getValue('branch');
+      if (strlen($pattern)) {
+        $pattern_argv = array($pattern);
+      } else {
+        $pattern_argv = array();
+      }
+
       // NOTE: We can't use DiffusionLowLevelGitRefQuery here because
       // `git for-each-ref` does not support `--contains`.
       if ($repository->isWorkingCopyBare()) {
         list($stdout) = $repository->execxLocalCommand(
-          'branch --verbose --no-abbrev --contains %s --',
+          'branch --verbose --no-abbrev --contains %s -- %Ls',
-          $contains);
+          $contains,
+          $pattern_argv);
         $ref_map = DiffusionGitBranch::parseLocalBranchOutput(
           $stdout);
       } else {
         list($stdout) = $repository->execxLocalCommand(
-          'branch -r --verbose --no-abbrev --contains %s --',
+          'branch -r --verbose --no-abbrev --contains %s -- %Ls',
-          $contains);
+          $contains,
+          $pattern_argv);
         $ref_map = DiffusionGitBranch::parseRemoteBranchOutput(
           $stdout,
           DiffusionGitBranch::DEFAULT_GIT_REMOTE);

src/applications/diffusion/controller/DiffusionCommitBranchesController.php

@@ -22,6 +22,7 @@ final class DiffusionCommitBranchesController extends DiffusionController {
         array(
           'contains' => $drequest->getCommit(),
           'limit' => $branch_limit + 1,
+          'branch' => null,
         )));
 
     $has_more_branches = (count($branches) > $branch_limit);