Allow Git repositories to track only some branches

Summary:
Some installs use Git as the backbone of a CI framework or use a Git remote to
share patches. The tracker scripts currently recognize associated revisions as
"Committed" when they appear in any branch, even if that branch is
"alincoln-personal-development_test_hack" or whatever.

To address the broadest need here, allow Git repositories to be configured to
track only certain branches instead of all branches.

This doesn't allow you to import a branch into Diffusion but ignore it in
Differential. Supporting that is somewhat technically complicated because the
parser currently goes like this:

  - Look at HEAD of all branches.
  - For any commits we haven't seen before, follow them back to something we
have seen (or the root).
  - "Discover" everything new.

Since this doesn't track <branch, commit> pairs, we currently don't have enough
information to tell when a commit appears in a branch for the first time, so we
don't have anywhere we can put a test for whether that branch is tracked and do
the Differential hook only if it is.

However, I think this cruder patch satisfies most of the need and is simple and
obvious in its implementation.

See also D1263.

Test Plan:
  - Updated a Git repository with various filters: "", "master, remote", "derp",
"  ,,, master   ,,,,,"
  - Edited SVN and Mercurial repositories to verify they didn't get caught in
the crossfire.
  - Ran daemon in debug mode on libphutil with filter "derp", got exception
about no tracked branches. Ran with filter "master", got tracking. Ran with no
filter, got tracking.
  - Looked at Diffusion with "derp" and "master", saw no branches and "master"
respectively.
  - Added unit tests to cover filtering logic.

Reviewers: btrahan, jungejason, nh, fratrik

Reviewed By: fratrik

CC: aran, fratrik, epriestley

Maniphest Tasks: T270

Differential Revision: https://secure.phabricator.com/D1290

src/applications/repository/controller/edit/PhabricatorRepositoryEditController.php

@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -229,6 +229,7 @@ class PhabricatorRepositoryEditController
 
     $has_branches       = ($is_git || $is_mercurial);
     $has_local          = ($is_git || $is_mercurial);
+    $has_branch_filter  = ($is_git);
     $has_http_support   = $is_svn;
 
     if ($request->isFormPost()) {
@@ -238,6 +239,14 @@ class PhabricatorRepositoryEditController
       if ($has_local) {
         $repository->setDetail('local-path', $request->getStr('path'));
       }
+
+      if ($has_branch_filter) {
+        $branch_filter = $request->getStrList('branch-filter');
+        $branch_filter = array_fill_keys($branch_filter, true);
+
+        $repository->setDetail('branch-filter', $branch_filter);
+      }
+
       $repository->setDetail(
         'pull-frequency',
         max(1, $request->getInt('frequency')));
@@ -548,6 +557,22 @@ class PhabricatorRepositoryEditController
           ->setError($e_path));
     }
 
+    if ($has_branch_filter) {
+      $branch_filter_str = implode(
+        ', ',
+        array_keys($repository->getDetail('branch-filter', array())));
+      $form
+        ->appendChild(
+          id(new AphrontFormTextControl())
+            ->setName('branch-filter')
+            ->setLabel('Track Only')
+            ->setValue($branch_filter_str)
+            ->setCaption(
+              'Optional list of branches to track. Other branches will be '.
+              'completely ignored. If left empty, all branches are tracked. '.
+              'Example: <tt>master, release</tt>'));
+    }
+
     $form
       ->appendChild(
         id(new AphrontFormTextControl())
@@ -584,7 +609,7 @@ class PhabricatorRepositoryEditController
                 $default_branch_name))
             ->setError($e_branch)
             ->setCaption(
-              'Default <strong>remote</strong> branch to show in Diffusion.'));
+              'Default branch to show in Diffusion.'));
     }
 
     $form