diff --git a/src/applications/diffusion/application/PhabricatorDiffusionApplication.php b/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
index 20b6f5e4cd..0f809e9983 100644
--- a/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
+++ b/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
@@ -1,181 +1,182 @@
 <?php
 
 final class PhabricatorDiffusionApplication extends PhabricatorApplication {
 
   public function getName() {
     return pht('Diffusion');
   }
 
   public function getShortDescription() {
     return pht('Host and Browse Repositories');
   }
 
   public function getBaseURI() {
     return '/diffusion/';
   }
 
   public function getFontIcon() {
     return 'fa-code';
   }
 
   public function isPinnedByDefault(PhabricatorUser $viewer) {
     return true;
   }
 
   public function getHelpDocumentationArticles(PhabricatorUser $viewer) {
     return array(
       array(
         'name' => pht('Diffusion User Guide'),
         'href' => PhabricatorEnv::getDoclink('Diffusion User Guide'),
       ),
     );
   }
 
   public function getFactObjectsForAnalysis() {
     return array(
       new PhabricatorRepositoryCommit(),
     );
   }
 
   public function getRemarkupRules() {
     return array(
       new DiffusionCommitRemarkupRule(),
       new DiffusionRepositoryRemarkupRule(),
       new DiffusionRepositoryByIDRemarkupRule(),
     );
   }
 
   public function getRoutes() {
     return array(
       '/(?:'.
         'r(?P<repositoryCallsign>[A-Z]+)'.
         '|'.
         'R(?P<repositoryID>[1-9]\d*):'.
       ')(?P<commit>[a-f0-9]+)'
         => 'DiffusionCommitController',
 
       '/diffusion/' => array(
         '(?:query/(?P<queryKey>[^/]+)/)?'
           => 'DiffusionRepositoryListController',
         'new/' => 'DiffusionRepositoryNewController',
         '(?P<edit>create)/' => 'DiffusionRepositoryCreateController',
         '(?P<edit>import)/' => 'DiffusionRepositoryCreateController',
         'pushlog/' => array(
           '(?:query/(?P<queryKey>[^/]+)/)?' => 'DiffusionPushLogListController',
           'view/(?P<id>\d+)/' => 'DiffusionPushEventViewController',
         ),
-        '(?P<repositoryCallsign>(?P<callsign>[A-Z]+))/' => array(
+        '(?P<repositoryCallsign>[A-Z]+)/' => array(
           '' => 'DiffusionRepositoryController',
 
           'repository/(?P<dblob>.*)'    => 'DiffusionRepositoryController',
           'change/(?P<dblob>.*)'        => 'DiffusionChangeController',
           'history/(?P<dblob>.*)'       => 'DiffusionHistoryController',
           'browse/(?P<dblob>.*)'        => 'DiffusionBrowseController',
           'lastmodified/(?P<dblob>.*)'  => 'DiffusionLastModifiedController',
           'diff/'                       => 'DiffusionDiffController',
           'tags/(?P<dblob>.*)'          => 'DiffusionTagListController',
           'branches/(?P<dblob>.*)'      => 'DiffusionBranchTableController',
           'refs/(?P<dblob>.*)'          => 'DiffusionRefTableController',
           'lint/(?P<dblob>.*)'          => 'DiffusionLintController',
           'commit/(?P<commit>[a-z0-9]+)/branches/'
             => 'DiffusionCommitBranchesController',
           'commit/(?P<commit>[a-z0-9]+)/tags/'
             => 'DiffusionCommitTagsController',
           'commit/(?P<commit>[a-z0-9]+)/edit/'
             => 'DiffusionCommitEditController',
           'edit/' => array(
             '' => 'DiffusionRepositoryEditMainController',
             'basic/' => 'DiffusionRepositoryEditBasicController',
             'encoding/' => 'DiffusionRepositoryEditEncodingController',
             'activate/' => 'DiffusionRepositoryEditActivateController',
             'dangerous/' => 'DiffusionRepositoryEditDangerousController',
             'branches/' => 'DiffusionRepositoryEditBranchesController',
             'subversion/' => 'DiffusionRepositoryEditSubversionController',
             'actions/' => 'DiffusionRepositoryEditActionsController',
             '(?P<edit>remote)/' => 'DiffusionRepositoryCreateController',
             '(?P<edit>policy)/' => 'DiffusionRepositoryCreateController',
             'storage/' => 'DiffusionRepositoryEditStorageController',
             'delete/' => 'DiffusionRepositoryEditDeleteController',
             'hosting/' => 'DiffusionRepositoryEditHostingController',
             '(?P<serve>serve)/' => 'DiffusionRepositoryEditHostingController',
             'update/' => 'DiffusionRepositoryEditUpdateController',
             'symbol/' => 'DiffusionRepositorySymbolsController',
             'staging/' => 'DiffusionRepositoryEditStagingController',
             'automation/' => 'DiffusionRepositoryEditAutomationController',
             'testautomation/' => 'DiffusionRepositoryTestAutomationController',
           ),
           'pathtree/(?P<dblob>.*)' => 'DiffusionPathTreeController',
           'mirror/' => array(
             'edit/(?:(?P<id>\d+)/)?' => 'DiffusionMirrorEditController',
             'delete/(?P<id>\d+)/' => 'DiffusionMirrorDeleteController',
           ),
         ),
 
         // NOTE: This must come after the rule above; it just gives us a
         // catch-all for serving repositories over HTTP. We must accept
         // requests without the trailing "/" because SVN commands don't
         // necessarily include it.
-        '(?P<callsign>[A-Z]+)(/|$).*' => 'DiffusionRepositoryDefaultController',
+        '(?P<repositoryCallsign>[A-Z]+)(?:/.*)?' =>
+          'DiffusionRepositoryDefaultController',
 
         'inline/' => array(
           'edit/(?P<phid>[^/]+)/' => 'DiffusionInlineCommentController',
           'preview/(?P<phid>[^/]+)/'
             => 'DiffusionInlineCommentPreviewController',
         ),
         'services/' => array(
           'path/' => array(
             'complete/' => 'DiffusionPathCompleteController',
             'validate/' => 'DiffusionPathValidateController',
           ),
         ),
         'symbol/(?P<name>[^/]+)/' => 'DiffusionSymbolController',
         'external/' => 'DiffusionExternalController',
         'lint/' => 'DiffusionLintController',
       ),
     );
   }
 
   public function getApplicationOrder() {
     return 0.120;
   }
 
   protected function getCustomCapabilities() {
     return array(
       DiffusionDefaultViewCapability::CAPABILITY => array(
         'template' => PhabricatorRepositoryRepositoryPHIDType::TYPECONST,
         'capability' => PhabricatorPolicyCapability::CAN_VIEW,
       ),
       DiffusionDefaultEditCapability::CAPABILITY => array(
         'default' => PhabricatorPolicies::POLICY_ADMIN,
         'template' => PhabricatorRepositoryRepositoryPHIDType::TYPECONST,
         'capability' => PhabricatorPolicyCapability::CAN_EDIT,
       ),
       DiffusionDefaultPushCapability::CAPABILITY => array(
         'template' => PhabricatorRepositoryRepositoryPHIDType::TYPECONST,
       ),
       DiffusionCreateRepositoriesCapability::CAPABILITY => array(
         'default' => PhabricatorPolicies::POLICY_ADMIN,
       ),
     );
   }
 
   public function getMailCommandObjects() {
     return array(
       'commit' => array(
         'name' => pht('Email Commands: Commits'),
         'header' => pht('Interacting with Commits'),
         'object' => new PhabricatorRepositoryCommit(),
         'summary' => pht(
           'This page documents the commands you can use to interact with '.
           'commits and audits in Diffusion.'),
       ),
     );
   }
 
   public function getApplicationSearchDocumentTypes() {
     return array(
       PhabricatorRepositoryCommitPHIDType::TYPECONST,
     );
   }
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionController.php b/src/applications/diffusion/controller/DiffusionController.php
index 5f1d8aa5fb..80364fd2ef 100644
--- a/src/applications/diffusion/controller/DiffusionController.php
+++ b/src/applications/diffusion/controller/DiffusionController.php
@@ -1,311 +1,290 @@
 <?php
 
 abstract class DiffusionController extends PhabricatorController {
 
-  protected $diffusionRequest;
-
-  public function setDiffusionRequest(DiffusionRequest $request) {
-    $this->diffusionRequest = $request;
-    return $this;
-  }
+  private $diffusionRequest;
 
   protected function getDiffusionRequest() {
     if (!$this->diffusionRequest) {
-      throw new Exception(pht('No Diffusion request object!'));
+      throw new PhutilInvalidStateException('loadDiffusionContext');
     }
     return $this->diffusionRequest;
   }
 
+  protected function hasDiffusionRequest() {
+    return (bool)$this->diffusionRequest;
+  }
+
   public function willBeginExecution() {
     $request = $this->getRequest();
 
     // Check if this is a VCS request, e.g. from "git clone", "hg clone", or
     // "svn checkout". If it is, we jump off into repository serving code to
     // process the request.
-    if (DiffusionServeController::isVCSRequest($request)) {
-      $serve_controller = id(new DiffusionServeController())
-        ->setCurrentApplication($this->getCurrentApplication());
+
+    $serve_controller = new DiffusionServeController();
+    if ($serve_controller->isVCSRequest($request)) {
       return $this->delegateToController($serve_controller);
     }
 
     return parent::willBeginExecution();
   }
 
-  protected function shouldLoadDiffusionRequest() {
-    return true;
-  }
-
-  public function handleRequest(AphrontRequest $request) {
-    if ($request->getURIData('callsign') &&
-        $this->shouldLoadDiffusionRequest()) {
-      try {
-      $drequest = DiffusionRequest::newFromAphrontRequestDictionary(
-        $request->getURIMap(),
-        $request);
-      } catch (Exception $ex) {
-        return id(new Aphront404Response())
-          ->setRequest($request);
-      }
-      $this->setDiffusionRequest($drequest);
-    }
-
-    return $this->processDiffusionRequest($request);
-  }
-
   protected function loadDiffusionContextForEdit() {
     return $this->loadContext(
       array(
         'edit' => true,
       ));
   }
 
   protected function loadDiffusionContext() {
     return $this->loadContext(array());
   }
 
   private function loadContext(array $options) {
     $request = $this->getRequest();
     $viewer = $this->getViewer();
 
     $identifier = $this->getRepositoryIdentifierFromRequest($request);
 
     $params = $options + array(
       'repository' => $identifier,
       'user' => $viewer,
       'blob' => $this->getDiffusionBlobFromRequest($request),
       'commit' => $request->getURIData('commit'),
       'path' => $request->getURIData('path'),
       'line' => $request->getURIData('line'),
       'branch' => $request->getURIData('branch'),
       'lint' => $request->getStr('lint'),
     );
 
     $drequest = DiffusionRequest::newFromDictionary($params);
 
     if (!$drequest) {
       return new Aphront404Response();
     }
 
     $this->diffusionRequest = $drequest;
 
     return null;
   }
 
   protected function getDiffusionBlobFromRequest(AphrontRequest $request) {
     return $request->getURIData('dblob');
   }
 
   protected function getRepositoryIdentifierFromRequest(
     AphrontRequest $request) {
 
     $identifier = $request->getURIData('repositoryCallsign');
     if (strlen($identifier)) {
       return $identifier;
     }
 
-    return (int)$request->getURIData('repositoryID');
-  }
+    $id = $request->getURIData('repositoryID');
+    if (strlen($id)) {
+      return (int)$id;
+    }
 
-  protected function processDiffusionRequest(AphrontRequest $request) {
-    throw new PhutilMethodNotImplementedException();
+    return null;
   }
 
   public function buildCrumbs(array $spec = array()) {
     $crumbs = $this->buildApplicationCrumbs();
     $crumb_list = $this->buildCrumbList($spec);
     foreach ($crumb_list as $crumb) {
       $crumbs->addCrumb($crumb);
     }
     return $crumbs;
   }
 
   private function buildCrumbList(array $spec = array()) {
 
     $spec = $spec + array(
       'commit'  => null,
       'tags'    => null,
       'branches'    => null,
       'view'    => null,
     );
 
     $crumb_list = array();
 
     // On the home page, we don't have a DiffusionRequest.
     if ($this->diffusionRequest) {
       $drequest = $this->getDiffusionRequest();
       $repository = $drequest->getRepository();
     } else {
       $drequest = null;
       $repository = null;
     }
 
     if (!$repository) {
       return $crumb_list;
     }
 
     $repository_name = $repository->getName();
 
     if (!$spec['commit'] && !$spec['tags'] && !$spec['branches']) {
       $branch_name = $drequest->getBranch();
       if ($branch_name) {
         $repository_name .= ' ('.$branch_name.')';
       }
     }
 
     $crumb = id(new PHUICrumbView())
       ->setName($repository_name);
     if (!$spec['view'] && !$spec['commit'] &&
         !$spec['tags'] && !$spec['branches']) {
       $crumb_list[] = $crumb;
       return $crumb_list;
     }
     $crumb->setHref(
       $drequest->generateURI(
         array(
           'action' => 'branch',
           'path' => '/',
         )));
     $crumb_list[] = $crumb;
 
     $stable_commit = $drequest->getStableCommit();
     $commit_name = $repository->formatCommitName($stable_commit);
     $commit_uri = $repository->getCommitURI($stable_commit);
 
     if ($spec['tags']) {
       $crumb = new PHUICrumbView();
       if ($spec['commit']) {
         $crumb->setName(pht('Tags for %s', $commit_name));
         $crumb->setHref($commit_uri);
       } else {
         $crumb->setName(pht('Tags'));
       }
       $crumb_list[] = $crumb;
       return $crumb_list;
     }
 
     if ($spec['branches']) {
       $crumb = id(new PHUICrumbView())
         ->setName(pht('Branches'));
       $crumb_list[] = $crumb;
       return $crumb_list;
     }
 
     if ($spec['commit']) {
       $crumb = id(new PHUICrumbView())
         ->setName($commit_name)
         ->setHref($commit_uri);
       $crumb_list[] = $crumb;
       return $crumb_list;
     }
 
     $crumb = new PHUICrumbView();
     $view = $spec['view'];
 
     switch ($view) {
       case 'history':
         $view_name = pht('History');
         break;
       case 'browse':
         $view_name = pht('Browse');
         break;
       case 'lint':
         $view_name = pht('Lint');
         break;
       case 'change':
         $view_name = pht('Change');
         break;
     }
 
     $crumb = id(new PHUICrumbView())
       ->setName($view_name);
 
     $crumb_list[] = $crumb;
     return $crumb_list;
   }
 
   protected function callConduitWithDiffusionRequest(
     $method,
     array $params = array()) {
 
     $user = $this->getRequest()->getUser();
     $drequest = $this->getDiffusionRequest();
 
     return DiffusionQuery::callConduitWithDiffusionRequest(
       $user,
       $drequest,
       $method,
       $params);
   }
 
   protected function getRepositoryControllerURI(
     PhabricatorRepository $repository,
     $path) {
     return $repository->getPathURI($path);
   }
 
   protected function renderPathLinks(DiffusionRequest $drequest, $action) {
     $path = $drequest->getPath();
     $path_parts = array_filter(explode('/', trim($path, '/')));
 
     $divider = phutil_tag(
       'span',
       array(
         'class' => 'phui-header-divider',
       ),
       '/');
 
     $links = array();
     if ($path_parts) {
       $links[] = phutil_tag(
         'a',
         array(
           'href' => $drequest->generateURI(
             array(
               'action' => $action,
               'path' => '',
             )),
         ),
         $drequest->getRepository()->getDisplayName());
       $links[] = $divider;
       $accum = '';
       $last_key = last_key($path_parts);
       foreach ($path_parts as $key => $part) {
         $accum .= '/'.$part;
         if ($key === $last_key) {
           $links[] = $part;
         } else {
           $links[] = phutil_tag(
             'a',
             array(
               'href' => $drequest->generateURI(
                 array(
                   'action' => $action,
                   'path' => $accum.'/',
                 )),
             ),
             $part);
           $links[] = $divider;
         }
       }
     } else {
       $links[] = $drequest->getRepository()->getDisplayName();
       $links[] = $divider;
     }
 
     return $links;
   }
 
   protected function renderStatusMessage($title, $body) {
     return id(new PHUIInfoView())
       ->setSeverity(PHUIInfoView::SEVERITY_WARNING)
       ->setTitle($title)
       ->appendChild($body);
   }
 
   protected function renderTablePagerBox(PHUIPagerView $pager) {
     return id(new PHUIBoxView())
       ->addMargin(PHUI::MARGIN_LARGE)
       ->appendChild($pager);
   }
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionRepositoryEditController.php b/src/applications/diffusion/controller/DiffusionRepositoryEditController.php
index 68749b1132..1e3cb553da 100644
--- a/src/applications/diffusion/controller/DiffusionRepositoryEditController.php
+++ b/src/applications/diffusion/controller/DiffusionRepositoryEditController.php
@@ -1,26 +1,27 @@
 <?php
 
 abstract class DiffusionRepositoryEditController
   extends DiffusionController {
 
   protected function buildApplicationCrumbs($is_main = false) {
     $crumbs = parent::buildApplicationCrumbs();
 
-    if ($this->diffusionRequest) {
-      $repository = $this->getDiffusionRequest()->getRepository();
+    if ($this->hasDiffusionRequest()) {
+      $drequest = $this->getDiffusionRequest();
+      $repository = $drequest->getRepository();
       $repo_uri = $repository->getURI();
       $edit_uri = $this->getRepositoryControllerURI($repository, 'edit/');
 
       $crumbs->addTextCrumb($repository->getDisplayname(), $repo_uri);
 
       if ($is_main) {
         $crumbs->addTextCrumb(pht('Edit Repository'));
       } else {
         $crumbs->addTextCrumb(pht('Edit'), $edit_uri);
       }
     }
 
     return $crumbs;
   }
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionServeController.php b/src/applications/diffusion/controller/DiffusionServeController.php
index 271ab36e91..ea5d4c209d 100644
--- a/src/applications/diffusion/controller/DiffusionServeController.php
+++ b/src/applications/diffusion/controller/DiffusionServeController.php
@@ -1,650 +1,635 @@
 <?php
 
 final class DiffusionServeController extends DiffusionController {
 
-  protected function shouldLoadDiffusionRequest() {
-    return false;
-  }
-
-  public static function isVCSRequest(AphrontRequest $request) {
-    if (!self::getCallsign($request)) {
+  public function isVCSRequest(AphrontRequest $request) {
+    $identifier = $this->getRepositoryIdentifierFromRequest($request);
+    if ($identifier === null) {
       return null;
     }
 
     $content_type = $request->getHTTPHeader('Content-Type');
     $user_agent = idx($_SERVER, 'HTTP_USER_AGENT');
 
     $vcs = null;
     if ($request->getExists('service')) {
       $service = $request->getStr('service');
       // We get this initially for `info/refs`.
       // Git also gives us a User-Agent like "git/1.8.2.3".
       $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
     } else if (strncmp($user_agent, 'git/', 4) === 0) {
       $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
     } else if ($content_type == 'application/x-git-upload-pack-request') {
       // We get this for `git-upload-pack`.
       $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
     } else if ($content_type == 'application/x-git-receive-pack-request') {
       // We get this for `git-receive-pack`.
       $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
     } else if ($request->getExists('cmd')) {
       // Mercurial also sends an Accept header like
       // "application/mercurial-0.1", and a User-Agent like
       // "mercurial/proto-1.0".
       $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL;
     } else {
       // Subversion also sends an initial OPTIONS request (vs GET/POST), and
       // has a User-Agent like "SVN/1.8.3 (x86_64-apple-darwin11.4.2)
       // serf/1.3.2".
       $dav = $request->getHTTPHeader('DAV');
       $dav = new PhutilURI($dav);
       if ($dav->getDomain() === 'subversion.tigris.org') {
         $vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_SVN;
       }
     }
 
     return $vcs;
   }
 
-  private static function getCallsign(AphrontRequest $request) {
-    $uri = $request->getRequestURI();
-
-    $regex = '@^/diffusion/(?P<callsign>[A-Z]+)(/|$)@';
-    $matches = null;
-    if (!preg_match($regex, (string)$uri, $matches)) {
-      return null;
-    }
-
-    return $matches['callsign'];
-  }
-
-  protected function processDiffusionRequest(AphrontRequest $request) {
-    $callsign = self::getCallsign($request);
+  public function handleRequest(AphrontRequest $request) {
+    $identifier = $this->getRepositoryIdentifierFromRequest($request);
 
     // If authentication credentials have been provided, try to find a user
     // that actually matches those credentials.
     if (isset($_SERVER['PHP_AUTH_USER']) && isset($_SERVER['PHP_AUTH_PW'])) {
       $username = $_SERVER['PHP_AUTH_USER'];
       $password = new PhutilOpaqueEnvelope($_SERVER['PHP_AUTH_PW']);
 
       $viewer = $this->authenticateHTTPRepositoryUser($username, $password);
       if (!$viewer) {
         return new PhabricatorVCSResponse(
           403,
           pht('Invalid credentials.'));
       }
     } else {
       // User hasn't provided credentials, which means we count them as
       // being "not logged in".
       $viewer = new PhabricatorUser();
     }
 
     $allow_public = PhabricatorEnv::getEnvConfig('policy.allow-public');
     $allow_auth = PhabricatorEnv::getEnvConfig('diffusion.allow-http-auth');
     if (!$allow_public) {
       if (!$viewer->isLoggedIn()) {
         if ($allow_auth) {
           return new PhabricatorVCSResponse(
             401,
             pht('You must log in to access repositories.'));
         } else {
           return new PhabricatorVCSResponse(
             403,
             pht('Public and authenticated HTTP access are both forbidden.'));
         }
       }
     }
 
     try {
       $repository = id(new PhabricatorRepositoryQuery())
         ->setViewer($viewer)
-        ->withCallsigns(array($callsign))
+        ->withIdentifiers(array($identifier))
         ->executeOne();
       if (!$repository) {
         return new PhabricatorVCSResponse(
           404,
           pht('No such repository exists.'));
       }
     } catch (PhabricatorPolicyException $ex) {
       if ($viewer->isLoggedIn()) {
         return new PhabricatorVCSResponse(
           403,
           pht('You do not have permission to access this repository.'));
       } else {
         if ($allow_auth) {
           return new PhabricatorVCSResponse(
             401,
             pht('You must log in to access this repository.'));
         } else {
           return new PhabricatorVCSResponse(
             403,
             pht(
               'This repository requires authentication, which is forbidden '.
               'over HTTP.'));
         }
       }
     }
 
     if (!$repository->isTracked()) {
       return new PhabricatorVCSResponse(
         403,
         pht('This repository is inactive.'));
     }
 
     $is_push = !$this->isReadOnlyRequest($repository);
 
     switch ($repository->getServeOverHTTP()) {
       case PhabricatorRepository::SERVE_READONLY:
         if ($is_push) {
           return new PhabricatorVCSResponse(
             403,
             pht('This repository is read-only over HTTP.'));
         }
         break;
       case PhabricatorRepository::SERVE_READWRITE:
         if ($is_push) {
           $can_push = PhabricatorPolicyFilter::hasCapability(
             $viewer,
             $repository,
             DiffusionPushCapability::CAPABILITY);
           if (!$can_push) {
             if ($viewer->isLoggedIn()) {
               return new PhabricatorVCSResponse(
                 403,
                 pht('You do not have permission to push to this repository.'));
             } else {
               if ($allow_auth) {
                 return new PhabricatorVCSResponse(
                   401,
                   pht('You must log in to push to this repository.'));
               } else {
                 return new PhabricatorVCSResponse(
                   403,
                   pht(
                     'Pushing to this repository requires authentication, '.
                     'which is forbidden over HTTP.'));
               }
             }
           }
         }
         break;
       case PhabricatorRepository::SERVE_OFF:
       default:
         return new PhabricatorVCSResponse(
           403,
           pht('This repository is not available over HTTP.'));
     }
 
     $vcs_type = $repository->getVersionControlSystem();
     $req_type = $this->isVCSRequest($request);
 
     if ($vcs_type != $req_type) {
       switch ($req_type) {
         case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
           $result = new PhabricatorVCSResponse(
             500,
             pht('This is not a Git repository.'));
           break;
         case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
           $result = new PhabricatorVCSResponse(
             500,
             pht('This is not a Mercurial repository.'));
           break;
         case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
           $result = new PhabricatorVCSResponse(
             500,
             pht('This is not a Subversion repository.'));
           break;
         default:
           $result = new PhabricatorVCSResponse(
             500,
             pht('Unknown request type.'));
           break;
       }
     } else {
       switch ($vcs_type) {
         case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
           $result = $this->serveVCSRequest($repository, $viewer);
           break;
         case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
           $result = new PhabricatorVCSResponse(
             500,
             pht(
               'Phabricator does not support HTTP access to Subversion '.
               'repositories.'));
           break;
         default:
           $result = new PhabricatorVCSResponse(
             500,
             pht('Unknown version control system.'));
           break;
       }
     }
 
     $code = $result->getHTTPResponseCode();
 
     if ($is_push && ($code == 200)) {
       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
         $repository->writeStatusMessage(
           PhabricatorRepositoryStatusMessage::TYPE_NEEDS_UPDATE,
           PhabricatorRepositoryStatusMessage::CODE_OKAY);
       unset($unguarded);
     }
 
     return $result;
   }
 
   private function serveVCSRequest(
     PhabricatorRepository $repository,
     PhabricatorUser $viewer) {
 
     // If this repository is hosted on a service, we need to proxy the request
     // to a host which can serve it.
     $is_cluster_request = $this->getRequest()->isProxiedClusterRequest();
 
     $uri = $repository->getAlmanacServiceURI(
       $viewer,
       $is_cluster_request,
       array(
         'http',
         'https',
       ));
     if ($uri) {
       $future = $this->getRequest()->newClusterProxyFuture($uri);
       return id(new AphrontHTTPProxyResponse())
         ->setHTTPFuture($future);
     }
 
     // Otherwise, we're going to handle the request locally.
 
     $vcs_type = $repository->getVersionControlSystem();
     switch ($vcs_type) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         $result = $this->serveGitRequest($repository, $viewer);
         break;
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         $result = $this->serveMercurialRequest($repository, $viewer);
         break;
     }
 
     return $result;
   }
 
   private function isReadOnlyRequest(
     PhabricatorRepository $repository) {
     $request = $this->getRequest();
     $method = $_SERVER['REQUEST_METHOD'];
 
     // TODO: This implementation is safe by default, but very incomplete.
 
     switch ($repository->getVersionControlSystem()) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         $service = $request->getStr('service');
         $path = $this->getRequestDirectoryPath($repository);
         // NOTE: Service names are the reverse of what you might expect, as they
         // are from the point of view of the server. The main read service is
         // "git-upload-pack", and the main write service is "git-receive-pack".
 
         if ($method == 'GET' &&
             $path == '/info/refs' &&
             $service == 'git-upload-pack') {
           return true;
         }
 
         if ($path == '/git-upload-pack') {
           return true;
         }
 
         break;
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         $cmd = $request->getStr('cmd');
         if ($cmd == 'batch') {
           $cmds = idx($this->getMercurialArguments(), 'cmds');
           return DiffusionMercurialWireProtocol::isReadOnlyBatchCommand($cmds);
         }
         return DiffusionMercurialWireProtocol::isReadOnlyCommand($cmd);
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         break;
     }
 
     return false;
   }
 
   /**
    * @phutil-external-symbol class PhabricatorStartup
    */
   private function serveGitRequest(
     PhabricatorRepository $repository,
     PhabricatorUser $viewer) {
     $request = $this->getRequest();
 
     $request_path = $this->getRequestDirectoryPath($repository);
     $repository_root = $repository->getLocalPath();
 
     // Rebuild the query string to strip `__magic__` parameters and prevent
     // issues where we might interpret inputs like "service=read&service=write"
     // differently than the server does and pass it an unsafe command.
 
     // NOTE: This does not use getPassthroughRequestParameters() because
     // that code is HTTP-method agnostic and will encode POST data.
 
     $query_data = $_GET;
     foreach ($query_data as $key => $value) {
       if (!strncmp($key, '__', 2)) {
         unset($query_data[$key]);
       }
     }
     $query_string = http_build_query($query_data, '', '&');
 
     // We're about to wipe out PATH with the rest of the environment, so
     // resolve the binary first.
     $bin = Filesystem::resolveBinary('git-http-backend');
     if (!$bin) {
       throw new Exception(
         pht(
           'Unable to find `%s` in %s!',
           'git-http-backend',
           '$PATH'));
     }
 
     $env = array(
       'REQUEST_METHOD' => $_SERVER['REQUEST_METHOD'],
       'QUERY_STRING' => $query_string,
       'CONTENT_TYPE' => $request->getHTTPHeader('Content-Type'),
       'HTTP_CONTENT_ENCODING' => $request->getHTTPHeader('Content-Encoding'),
       'REMOTE_ADDR' => $_SERVER['REMOTE_ADDR'],
       'GIT_PROJECT_ROOT' => $repository_root,
       'GIT_HTTP_EXPORT_ALL' => '1',
       'PATH_INFO' => $request_path,
 
       'REMOTE_USER' => $viewer->getUsername(),
 
       // TODO: Set these correctly.
       // GIT_COMMITTER_NAME
       // GIT_COMMITTER_EMAIL
     ) + $this->getCommonEnvironment($viewer);
 
     $input = PhabricatorStartup::getRawInput();
 
     $command = csprintf('%s', $bin);
     $command = PhabricatorDaemon::sudoCommandAsDaemonUser($command);
 
     list($err, $stdout, $stderr) = id(new ExecFuture('%C', $command))
       ->setEnv($env, true)
       ->write($input)
       ->resolve();
 
     if ($err) {
       if ($this->isValidGitShallowCloneResponse($stdout, $stderr)) {
         // Ignore the error if the response passes this special check for
         // validity.
         $err = 0;
       }
     }
 
     if ($err) {
       return new PhabricatorVCSResponse(
         500,
         pht('Error %d: %s', $err, $stderr));
     }
 
     return id(new DiffusionGitResponse())->setGitData($stdout);
   }
 
   private function getRequestDirectoryPath(PhabricatorRepository $repository) {
     $request = $this->getRequest();
     $request_path = $request->getRequestURI()->getPath();
     $base_path = preg_replace('@^/diffusion/[A-Z]+@', '', $request_path);
 
     // For Git repositories, strip an optional directory component if it
     // isn't the name of a known Git resource. This allows users to clone
     // repositories as "/diffusion/X/anything.git", for example.
     if ($repository->isGit()) {
       $known = array(
         'info',
         'git-upload-pack',
         'git-receive-pack',
       );
 
       foreach ($known as $key => $path) {
         $known[$key] = preg_quote($path, '@');
       }
 
       $known = implode('|', $known);
 
       if (preg_match('@^/([^/]+)/('.$known.')(/|$)@', $base_path)) {
         $base_path = preg_replace('@^/([^/]+)@', '', $base_path);
       }
     }
 
     return $base_path;
   }
 
   private function authenticateHTTPRepositoryUser(
     $username,
     PhutilOpaqueEnvelope $password) {
 
     if (!PhabricatorEnv::getEnvConfig('diffusion.allow-http-auth')) {
       // No HTTP auth permitted.
       return null;
     }
 
     if (!strlen($username)) {
       // No username.
       return null;
     }
 
     if (!strlen($password->openEnvelope())) {
       // No password.
       return null;
     }
 
     $user = id(new PhabricatorPeopleQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withUsernames(array($username))
       ->executeOne();
     if (!$user) {
       // Username doesn't match anything.
       return null;
     }
 
     if (!$user->isUserActivated()) {
       // User is not activated.
       return null;
     }
 
     $password_entry = id(new PhabricatorRepositoryVCSPassword())
       ->loadOneWhere('userPHID = %s', $user->getPHID());
     if (!$password_entry) {
       // User doesn't have a password set.
       return null;
     }
 
     if (!$password_entry->comparePassword($password, $user)) {
       // Password doesn't match.
       return null;
     }
 
     // If the user's password is stored using a less-than-optimal hash, upgrade
     // them to the strongest available hash.
 
     $hash_envelope = new PhutilOpaqueEnvelope(
       $password_entry->getPasswordHash());
     if (PhabricatorPasswordHasher::canUpgradeHash($hash_envelope)) {
       $password_entry->setPassword($password, $user);
       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
         $password_entry->save();
       unset($unguarded);
     }
 
     return $user;
   }
 
   private function serveMercurialRequest(
     PhabricatorRepository $repository,
     PhabricatorUser $viewer) {
     $request = $this->getRequest();
 
     $bin = Filesystem::resolveBinary('hg');
     if (!$bin) {
       throw new Exception(
         pht(
           'Unable to find `%s` in %s!',
           'hg',
           '$PATH'));
     }
 
     $env = $this->getCommonEnvironment($viewer);
     $input = PhabricatorStartup::getRawInput();
 
     $cmd = $request->getStr('cmd');
 
     $args = $this->getMercurialArguments();
     $args = $this->formatMercurialArguments($cmd, $args);
 
     if (strlen($input)) {
       $input = strlen($input)."\n".$input."0\n";
     }
 
     $command = csprintf('%s serve --stdio', $bin);
     $command = PhabricatorDaemon::sudoCommandAsDaemonUser($command);
 
     list($err, $stdout, $stderr) = id(new ExecFuture('%C', $command))
       ->setEnv($env, true)
       ->setCWD($repository->getLocalPath())
       ->write("{$cmd}\n{$args}{$input}")
       ->resolve();
 
     if ($err) {
       return new PhabricatorVCSResponse(
         500,
         pht('Error %d: %s', $err, $stderr));
     }
 
     if ($cmd == 'getbundle' ||
         $cmd == 'changegroup' ||
         $cmd == 'changegroupsubset') {
       // We're not completely sure that "changegroup" and "changegroupsubset"
       // actually work, they're for very old Mercurial.
       $body = gzcompress($stdout);
     } else if ($cmd == 'unbundle') {
       // This includes diagnostic information and anything echoed by commit
       // hooks. We ignore `stdout` since it just has protocol garbage, and
       // substitute `stderr`.
       $body = strlen($stderr)."\n".$stderr;
     } else {
       list($length, $body) = explode("\n", $stdout, 2);
       if ($cmd == 'capabilities') {
         $body = DiffusionMercurialWireProtocol::filterBundle2Capability($body);
       }
     }
 
     return id(new DiffusionMercurialResponse())->setContent($body);
   }
 
   private function getMercurialArguments() {
     // Mercurial sends arguments in HTTP headers. "Why?", you might wonder,
     // "Why would you do this?".
 
     $args_raw = array();
     for ($ii = 1;; $ii++) {
       $header = 'HTTP_X_HGARG_'.$ii;
       if (!array_key_exists($header, $_SERVER)) {
         break;
       }
       $args_raw[] = $_SERVER[$header];
     }
     $args_raw = implode('', $args_raw);
 
     return id(new PhutilQueryStringParser())
       ->parseQueryString($args_raw);
   }
 
   private function formatMercurialArguments($command, array $arguments) {
     $spec = DiffusionMercurialWireProtocol::getCommandArgs($command);
 
     $out = array();
 
     // Mercurial takes normal arguments like this:
     //
     //   name <length(value)>
     //   value
 
     $has_star = false;
     foreach ($spec as $arg_key) {
       if ($arg_key == '*') {
         $has_star = true;
         continue;
       }
       if (isset($arguments[$arg_key])) {
         $value = $arguments[$arg_key];
         $size = strlen($value);
         $out[] = "{$arg_key} {$size}\n{$value}";
         unset($arguments[$arg_key]);
       }
     }
 
     if ($has_star) {
 
       // Mercurial takes arguments for variable argument lists roughly like
       // this:
       //
       //   * <count(args)>
       //   argname1 <length(argvalue1)>
       //   argvalue1
       //   argname2 <length(argvalue2)>
       //   argvalue2
 
       $count = count($arguments);
 
       $out[] = "* {$count}\n";
 
       foreach ($arguments as $key => $value) {
         if (in_array($key, $spec)) {
           // We already added this argument above, so skip it.
           continue;
         }
         $size = strlen($value);
         $out[] = "{$key} {$size}\n{$value}";
       }
     }
 
     return implode('', $out);
   }
 
   private function isValidGitShallowCloneResponse($stdout, $stderr) {
     // If you execute `git clone --depth N ...`, git sends a request which
     // `git-http-backend` responds to by emitting valid output and then exiting
     // with a failure code and an error message. If we ignore this error,
     // everything works.
 
     // This is a pretty funky fix: it would be nice to more precisely detect
     // that a request is a `--depth N` clone request, but we don't have any code
     // to decode protocol frames yet. Instead, look for reasonable evidence
     // in the error and output that we're looking at a `--depth` clone.
 
     // For evidence this isn't completely crazy, see:
     // https://github.com/schacon/grack/pull/7
 
     $stdout_regexp = '(^Content-Type: application/x-git-upload-pack-result)m';
     $stderr_regexp = '(The remote end hung up unexpectedly)';
 
     $has_pack = preg_match($stdout_regexp, $stdout);
     $is_hangup = preg_match($stderr_regexp, $stderr);
 
     return $has_pack && $is_hangup;
   }
 
   private function getCommonEnvironment(PhabricatorUser $viewer) {
     $remote_addr = $this->getRequest()->getRemoteAddr();
 
     return array(
       DiffusionCommitHookEngine::ENV_USER => $viewer->getUsername(),
       DiffusionCommitHookEngine::ENV_REMOTE_ADDRESS => $remote_addr,
       DiffusionCommitHookEngine::ENV_REMOTE_PROTOCOL => 'http',
     );
   }
 
 }
diff --git a/src/applications/diffusion/request/DiffusionRequest.php b/src/applications/diffusion/request/DiffusionRequest.php
index 1373adfab1..8d326b81bc 100644
--- a/src/applications/diffusion/request/DiffusionRequest.php
+++ b/src/applications/diffusion/request/DiffusionRequest.php
@@ -1,734 +1,697 @@
 <?php
 
 /**
  * Contains logic to parse Diffusion requests, which have a complicated URI
  * structure.
  *
  * @task new Creating Requests
  * @task uri Managing Diffusion URIs
  */
 abstract class DiffusionRequest extends Phobject {
 
   protected $path;
   protected $line;
   protected $branch;
   protected $lint;
 
   protected $symbolicCommit;
   protected $symbolicType;
   protected $stableCommit;
 
   protected $repository;
   protected $repositoryCommit;
   protected $repositoryCommitData;
 
   private $isClusterRequest = false;
   private $initFromConduit = true;
   private $user;
   private $branchObject = false;
   private $refAlternatives;
 
   abstract public function supportsBranches();
   abstract protected function isStableCommit($symbol);
 
   protected function didInitialize() {
     return null;
   }
 
 
 /* -(  Creating Requests  )-------------------------------------------------- */
 
 
   /**
    * Create a new synthetic request from a parameter dictionary. If you need
    * a @{class:DiffusionRequest} object in order to issue a DiffusionQuery, you
    * can use this method to build one.
    *
    * Parameters are:
    *
    *   - `repository` Repository object or identifier.
    *   - `user` Viewing user. Required if `repository` is an identifier.
    *   - `branch` Optional, branch name.
    *   - `path` Optional, file path.
    *   - `commit` Optional, commit identifier.
    *   - `line` Optional, line range.
    *
    * @param   map                 See documentation.
    * @return  DiffusionRequest    New request object.
    * @task new
    */
   final public static function newFromDictionary(array $data) {
     $repository_key = 'repository';
     $identifier_key = 'callsign';
     $viewer_key = 'user';
 
     $repository = idx($data, $repository_key);
     $identifier = idx($data, $identifier_key);
 
     $have_repository = ($repository !== null);
     $have_identifier = ($identifier !== null);
 
     if ($have_repository && $have_identifier) {
       throw new Exception(
         pht(
           'Specify "%s" or "%s", but not both.',
           $repository_key,
           $identifier_key));
     }
 
     if (!$have_repository && !$have_identifier) {
       throw new Exception(
         pht(
           'One of "%s" and "%s" is required.',
           $repository_key,
           $identifier_key));
     }
 
     if ($have_repository) {
       if (!($repository instanceof PhabricatorRepository)) {
         if (empty($data[$viewer_key])) {
           throw new Exception(
             pht(
               'Parameter "%s" is required if "%s" is provided.',
               $viewer_key,
               $identifier_key));
         }
 
         $identifier = $repository;
         $repository = null;
       }
     }
 
     if ($identifier !== null) {
       $object = self::newFromIdentifier(
         $identifier,
         $data[$viewer_key],
         idx($data, 'edit'));
     } else {
       $object = self::newFromRepository($repository);
     }
 
     if (!$object) {
       return null;
     }
 
     $object->initializeFromDictionary($data);
 
     return $object;
   }
 
-
-  /**
-   * Create a new request from an Aphront request dictionary. This is an
-   * internal method that you generally should not call directly; instead,
-   * call @{method:newFromDictionary}.
-   *
-   * @param   map                 Map of Aphront request data.
-   * @return  DiffusionRequest    New request object.
-   * @task new
-   */
-  final public static function newFromAphrontRequestDictionary(
-    array $data,
-    AphrontRequest $request) {
-
-    $identifier = phutil_unescape_uri_path_component(idx($data, 'callsign'));
-    $object = self::newFromIdentifier($identifier, $request->getUser());
-
-    $use_branches = $object->supportsBranches();
-
-    if (isset($data['dblob'])) {
-      $parsed = self::parseRequestBlob(idx($data, 'dblob'), $use_branches);
-    } else {
-      $parsed = array(
-        'commit' => idx($data, 'commit'),
-        'path' => idx($data, 'path'),
-        'line' => idx($data, 'line'),
-        'branch' => idx($data, 'branch'),
-      );
-    }
-
-    $object->setUser($request->getUser());
-    $object->initializeFromDictionary($parsed);
-    $object->lint = $request->getStr('lint');
-    return $object;
-  }
-
-
   /**
    * Internal.
    *
    * @task new
    */
   final private function __construct() {
     // <private>
   }
 
 
   /**
    * Internal. Use @{method:newFromDictionary}, not this method.
    *
    * @param   string              Repository identifier.
    * @param   PhabricatorUser     Viewing user.
    * @return  DiffusionRequest    New request object.
    * @task new
    */
   final private static function newFromIdentifier(
     $identifier,
     PhabricatorUser $viewer,
     $need_edit = false) {
 
     $query = id(new PhabricatorRepositoryQuery())
       ->setViewer($viewer)
       ->withIdentifiers(array($identifier));
 
     if ($need_edit) {
       $query->requireCapabilities(
         array(
           PhabricatorPolicyCapability::CAN_VIEW,
           PhabricatorPolicyCapability::CAN_EDIT,
         ));
     }
 
     $repository = $query->executeOne();
 
     if (!$repository) {
       return null;
     }
 
     return self::newFromRepository($repository);
   }
 
 
   /**
    * Internal. Use @{method:newFromDictionary}, not this method.
    *
    * @param   PhabricatorRepository   Repository object.
    * @return  DiffusionRequest        New request object.
    * @task new
    */
   final private static function newFromRepository(
     PhabricatorRepository $repository) {
 
     $map = array(
       PhabricatorRepositoryType::REPOSITORY_TYPE_GIT => 'DiffusionGitRequest',
       PhabricatorRepositoryType::REPOSITORY_TYPE_SVN => 'DiffusionSvnRequest',
       PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL =>
         'DiffusionMercurialRequest',
     );
 
     $class = idx($map, $repository->getVersionControlSystem());
 
     if (!$class) {
       throw new Exception(pht('Unknown version control system!'));
     }
 
     $object = new $class();
 
     $object->repository = $repository;
 
     return $object;
   }
 
 
   /**
    * Internal. Use @{method:newFromDictionary}, not this method.
    *
    * @param map Map of parsed data.
    * @return void
    * @task new
    */
   final private function initializeFromDictionary(array $data) {
     $blob = idx($data, 'blob');
     if (strlen($blob)) {
       $blob = self::parseRequestBlob($blob, $this->supportsBranches());
       $data = $blob + $data;
     }
 
     $this->path = idx($data, 'path');
     $this->line = idx($data, 'line');
     $this->initFromConduit = idx($data, 'initFromConduit', true);
     $this->lint = idx($data, 'lint');
 
     $this->symbolicCommit = idx($data, 'commit');
     if ($this->supportsBranches()) {
       $this->branch = idx($data, 'branch');
     }
 
     if (!$this->getUser()) {
       $user = idx($data, 'user');
       if (!$user) {
         throw new Exception(
           pht(
             'You must provide a %s in the dictionary!',
             'PhabricatorUser'));
       }
       $this->setUser($user);
     }
 
     $this->didInitialize();
   }
 
   final public function setUser(PhabricatorUser $user) {
     $this->user = $user;
     return $this;
   }
   final public function getUser() {
     return $this->user;
   }
 
   public function getRepository() {
     return $this->repository;
   }
 
   public function getCallsign() {
     return $this->getRepository()->getCallsign();
   }
 
   public function setPath($path) {
     $this->path = $path;
     return $this;
   }
 
   public function getPath() {
     return $this->path;
   }
 
   public function getLine() {
     return $this->line;
   }
 
   public function getCommit() {
 
     // TODO: Probably remove all of this.
 
     if ($this->getSymbolicCommit() !== null) {
       return $this->getSymbolicCommit();
     }
 
     return $this->getStableCommit();
   }
 
   /**
    * Get the symbolic commit associated with this request.
    *
    * A symbolic commit may be a commit hash, an abbreviated commit hash, a
    * branch name, a tag name, or an expression like "HEAD^^^". The symbolic
    * commit may also be absent.
    *
    * This method always returns the symbol present in the original request,
    * in unmodified form.
    *
    * See also @{method:getStableCommit}.
    *
    * @return string|null  Symbolic commit, if one was present in the request.
    */
   public function getSymbolicCommit() {
     return $this->symbolicCommit;
   }
 
 
   /**
    * Modify the request to move the symbolic commit elsewhere.
    *
    * @param string New symbolic commit.
    * @return this
    */
   public function updateSymbolicCommit($symbol) {
     $this->symbolicCommit = $symbol;
     $this->symbolicType = null;
     $this->stableCommit = null;
     return $this;
   }
 
 
   /**
    * Get the ref type (`commit` or `tag`) of the location associated with this
    * request.
    *
    * If a symbolic commit is present in the request, this method identifies
    * the type of the symbol. Otherwise, it identifies the type of symbol of
    * the location the request is implicitly associated with. This will probably
    * always be `commit`.
    *
    * @return string   Symbolic commit type (`commit` or `tag`).
    */
   public function getSymbolicType() {
     if ($this->symbolicType === null) {
       // As a side effect, this resolves the symbolic type.
       $this->getStableCommit();
     }
     return $this->symbolicType;
   }
 
 
   /**
    * Retrieve the stable, permanent commit name identifying the repository
    * location associated with this request.
    *
    * This returns a non-symbolic identifier for the current commit: in Git and
    * Mercurial, a 40-character SHA1; in SVN, a revision number.
    *
    * See also @{method:getSymbolicCommit}.
    *
    * @return string Stable commit name, like a git hash or SVN revision. Not
    *                a symbolic commit reference.
    */
   public function getStableCommit() {
     if (!$this->stableCommit) {
       if ($this->isStableCommit($this->symbolicCommit)) {
         $this->stableCommit = $this->symbolicCommit;
         $this->symbolicType = 'commit';
       } else {
         $this->queryStableCommit();
       }
     }
     return $this->stableCommit;
   }
 
 
   public function getBranch() {
     return $this->branch;
   }
 
   public function getLint() {
     return $this->lint;
   }
 
   protected function getArcanistBranch() {
     return $this->getBranch();
   }
 
   public function loadBranch() {
     // TODO: Get rid of this and do real Queries on real objects.
 
     if ($this->branchObject === false) {
       $this->branchObject = PhabricatorRepositoryBranch::loadBranch(
         $this->getRepository()->getID(),
         $this->getArcanistBranch());
     }
 
     return $this->branchObject;
   }
 
   public function loadCoverage() {
     // TODO: This should also die.
     $branch = $this->loadBranch();
     if (!$branch) {
       return;
     }
 
     $path = $this->getPath();
     $path_map = id(new DiffusionPathIDQuery(array($path)))->loadPathIDs();
 
     $coverage_row = queryfx_one(
       id(new PhabricatorRepository())->establishConnection('r'),
       'SELECT * FROM %T WHERE branchID = %d AND pathID = %d
         ORDER BY commitID DESC LIMIT 1',
       'repository_coverage',
       $branch->getID(),
       $path_map[$path]);
 
     if (!$coverage_row) {
       return null;
     }
 
     return idx($coverage_row, 'coverage');
   }
 
 
   public function loadCommit() {
     if (empty($this->repositoryCommit)) {
       $repository = $this->getRepository();
 
       $commit = id(new DiffusionCommitQuery())
         ->setViewer($this->getUser())
         ->withRepository($repository)
         ->withIdentifiers(array($this->getStableCommit()))
         ->executeOne();
       if ($commit) {
         $commit->attachRepository($repository);
       }
       $this->repositoryCommit = $commit;
     }
     return $this->repositoryCommit;
   }
 
   public function loadCommitData() {
     if (empty($this->repositoryCommitData)) {
       $commit = $this->loadCommit();
       $data = id(new PhabricatorRepositoryCommitData())->loadOneWhere(
         'commitID = %d',
         $commit->getID());
       if (!$data) {
         $data = new PhabricatorRepositoryCommitData();
         $data->setCommitMessage(
           pht('(This commit has not been fully parsed yet.)'));
       }
       $this->repositoryCommitData = $data;
     }
     return $this->repositoryCommitData;
   }
 
 /* -(  Managing Diffusion URIs  )-------------------------------------------- */
 
 
   public function generateURI(array $params) {
     if (empty($params['stable'])) {
       $default_commit = $this->getSymbolicCommit();
     } else {
       $default_commit = $this->getStableCommit();
     }
 
     $defaults = array(
       'path'      => $this->getPath(),
       'branch'    => $this->getBranch(),
       'commit'    => $default_commit,
       'lint'      => idx($params, 'lint', $this->getLint()),
     );
 
     foreach ($defaults as $key => $val) {
       if (!isset($params[$key])) { // Overwrite NULL.
         $params[$key] = $val;
       }
     }
 
     return $this->getRepository()->generateURI($params);
   }
 
   /**
    * Internal. Public only for unit tests.
    *
    * Parse the request URI into components.
    *
    * @param   string  URI blob.
    * @param   bool    True if this VCS supports branches.
    * @return  map     Parsed URI.
    *
    * @task uri
    */
   public static function parseRequestBlob($blob, $supports_branches) {
     $result = array(
       'branch'  => null,
       'path'    => null,
       'commit'  => null,
       'line'    => null,
     );
 
     $matches = null;
 
     if ($supports_branches) {
       // Consume the front part of the URI, up to the first "/". This is the
       // path-component encoded branch name.
       if (preg_match('@^([^/]+)/@', $blob, $matches)) {
         $result['branch'] = phutil_unescape_uri_path_component($matches[1]);
         $blob = substr($blob, strlen($matches[1]) + 1);
       }
     }
 
     // Consume the back part of the URI, up to the first "$". Use a negative
     // lookbehind to prevent matching '$$'. We double the '$' symbol when
     // encoding so that files with names like "money/$100" will survive.
     $pattern = '@(?:(?:^|[^$])(?:[$][$])*)[$]([\d-,]+)$@';
     if (preg_match($pattern, $blob, $matches)) {
       $result['line'] = $matches[1];
       $blob = substr($blob, 0, -(strlen($matches[1]) + 1));
     }
 
     // We've consumed the line number if it exists, so unescape "$" in the
     // rest of the string.
     $blob = str_replace('$$', '$', $blob);
 
     // Consume the commit name, stopping on ';;'. We allow any character to
     // appear in commits names, as they can sometimes be symbolic names (like
     // tag names or refs).
     if (preg_match('@(?:(?:^|[^;])(?:;;)*);([^;].*)$@', $blob, $matches)) {
       $result['commit'] = $matches[1];
       $blob = substr($blob, 0, -(strlen($matches[1]) + 1));
     }
 
     // We've consumed the commit if it exists, so unescape ";" in the rest
     // of the string.
     $blob = str_replace(';;', ';', $blob);
 
     if (strlen($blob)) {
       $result['path'] = $blob;
     }
 
     $parts = explode('/', $result['path']);
     foreach ($parts as $part) {
       // Prevent any hyjinx since we're ultimately shipping this to the
       // filesystem under a lot of workflows.
       if ($part == '..') {
         throw new Exception(pht('Invalid path URI.'));
       }
     }
 
     return $result;
   }
 
   /**
    * Check that the working copy of the repository is present and readable.
    *
    * @param   string  Path to the working copy.
    */
   protected function validateWorkingCopy($path) {
     if (!is_readable(dirname($path))) {
       $this->raisePermissionException();
     }
 
     if (!Filesystem::pathExists($path)) {
       $this->raiseCloneException();
     }
   }
 
   protected function raisePermissionException() {
     $host = php_uname('n');
     throw new DiffusionSetupException(
       pht(
         'The clone of this repository ("%s") on the local machine ("%s") '.
         'could not be read. Ensure that the repository is in a '.
         'location where the web server has read permissions.',
         $this->getRepository()->getDisplayName(),
         $host));
   }
 
   protected function raiseCloneException() {
     $host = php_uname('n');
     throw new DiffusionSetupException(
       pht(
         'The working copy for this repository ("%s") has not been cloned yet '.
         'on this machine ("%s"). Make sure you havestarted the Phabricator '.
         'daemons. If this problem persists for longer than a clone should '.
         'take, check the daemon logs (in the Daemon Console) to see if there '.
         'were errors cloning the repository. Consult the "Diffusion User '.
         'Guide" in the documentation for help setting up repositories.',
         $this->getRepository()->getDisplayName(),
         $host));
   }
 
   private function queryStableCommit() {
     $types = array();
     if ($this->symbolicCommit) {
       $ref = $this->symbolicCommit;
     } else {
       if ($this->supportsBranches()) {
         $ref = $this->getBranch();
         $types = array(
           PhabricatorRepositoryRefCursor::TYPE_BRANCH,
         );
       } else {
         $ref = 'HEAD';
       }
     }
 
     $results = $this->resolveRefs(array($ref), $types);
 
     $matches = idx($results, $ref, array());
     if (!$matches) {
       $message = pht(
         'Ref "%s" does not exist in this repository.',
         $ref);
       throw id(new DiffusionRefNotFoundException($message))
         ->setRef($ref);
     }
 
     if (count($matches) > 1) {
       $match = $this->chooseBestRefMatch($ref, $matches);
     } else {
       $match = head($matches);
     }
 
     $this->stableCommit = $match['identifier'];
     $this->symbolicType = $match['type'];
   }
 
   public function getRefAlternatives() {
     // Make sure we've resolved the reference into a stable commit first.
     try {
       $this->getStableCommit();
     } catch (DiffusionRefNotFoundException $ex) {
       // If we have a bad reference, just return the empty set of
       // alternatives.
     }
     return $this->refAlternatives;
   }
 
   private function chooseBestRefMatch($ref, array $results) {
     // First, filter out less-desirable matches.
     $candidates = array();
     foreach ($results as $result) {
       // Exclude closed heads.
       if ($result['type'] == 'branch') {
         if (idx($result, 'closed')) {
           continue;
         }
       }
 
       $candidates[] = $result;
     }
 
     // If we filtered everything, undo the filtering.
     if (!$candidates) {
       $candidates = $results;
     }
 
     // TODO: Do a better job of selecting the best match?
     $match = head($candidates);
 
     // After choosing the best alternative, save all the alternatives so the
     // UI can show them to the user.
     if (count($candidates) > 1) {
       $this->refAlternatives = $candidates;
     }
 
     return $match;
   }
 
   private function resolveRefs(array $refs, array $types) {
     // First, try to resolve refs from fast cache sources.
     $cached_query = id(new DiffusionCachedResolveRefsQuery())
       ->setRepository($this->getRepository())
       ->withRefs($refs);
 
     if ($types) {
       $cached_query->withTypes($types);
     }
 
     $cached_results = $cached_query->execute();
 
     // Throw away all the refs we resolved. Hopefully, we'll throw away
     // everything here.
     foreach ($refs as $key => $ref) {
       if (isset($cached_results[$ref])) {
         unset($refs[$key]);
       }
     }
 
     // If we couldn't pull everything out of the cache, execute the underlying
     // VCS operation.
     if ($refs) {
       $vcs_results = DiffusionQuery::callConduitWithDiffusionRequest(
         $this->getUser(),
         $this,
         'diffusion.resolverefs',
         array(
           'types' => $types,
           'refs' => $refs,
         ));
     } else {
       $vcs_results = array();
     }
 
     return $vcs_results + $cached_results;
   }
 
   public function setIsClusterRequest($is_cluster_request) {
     $this->isClusterRequest = $is_cluster_request;
     return $this;
   }
 
   public function getIsClusterRequest() {
     return $this->isClusterRequest;
   }
 
 }