diff --git a/resources/sql/autopatches/20141119.differential.diff.policy.sql b/resources/sql/autopatches/20141119.differential.diff.policy.sql
new file mode 100644
index 0000000000..b6c19c0dea
--- /dev/null
+++ b/resources/sql/autopatches/20141119.differential.diff.policy.sql
@@ -0,0 +1,5 @@
+ALTER TABLE {$NAMESPACE}_differential.differential_diff
+  ADD viewPolicy VARBINARY(64) NOT NULL;
+
+UPDATE {$NAMESPACE}_differential.differential_diff
+  SET viewPolicy = 'users' WHERE viewPolicy = '';
diff --git a/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php b/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
index 41165bf23e..9d9f47315d 100644
--- a/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
+++ b/src/applications/differential/__tests__/DifferentialParseRenderTestCase.php
@@ -1,64 +1,66 @@
 <?php
 
 final class DifferentialParseRenderTestCase extends PhabricatorTestCase {
 
   public function testParseRender() {
     $dir = dirname(__FILE__).'/data/';
     foreach (Filesystem::listDirectory($dir, $show_hidden = false) as $file) {
       if (!preg_match('/\.diff$/', $file)) {
         continue;
       }
       $data = Filesystem::readFile($dir.$file);
 
       $opt_file = $dir.$file.'.options';
       if (Filesystem::pathExists($opt_file)) {
         $options = Filesystem::readFile($opt_file);
         $options = json_decode($options, true);
         if (!is_array($options)) {
           throw new Exception("Invalid options file: {$opt_file}.");
         }
       } else {
         $options = array();
       }
 
       foreach (array('one', 'two') as $type) {
         $parser = $this->buildChangesetParser($type, $data, $file);
         $actual = $parser->render(null, null, array());
 
         $expect = Filesystem::readFile($dir.$file.'.'.$type.'.expect');
         $this->assertEqual($expect, (string)$actual, $file.'.'.$type);
       }
     }
   }
 
   private function buildChangesetParser($type, $data, $file) {
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($data);
 
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $changes);
     if (count($diff->getChangesets()) !== 1) {
       throw new Exception("Expected one changeset: {$file}");
     }
 
     $changeset = head($diff->getChangesets());
 
     $engine = new PhabricatorMarkupEngine();
     $engine->setViewer(new PhabricatorUser());
 
     $cparser = new DifferentialChangesetParser();
     $cparser->setDisableCache(true);
     $cparser->setChangeset($changeset);
     $cparser->setMarkupEngine($engine);
 
     if ($type == 'one') {
       $cparser->setRenderer(new DifferentialChangesetOneUpTestRenderer());
     } else if ($type == 'two') {
       $cparser->setRenderer(new DifferentialChangesetTwoUpTestRenderer());
     } else {
       throw new Exception("Unknown renderer type '{$type}'!");
     }
 
     return $cparser;
   }
 
 }
diff --git a/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
index 3ea3c1768f..26b1c04ddd 100644
--- a/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCreateDiffConduitAPIMethod.php
@@ -1,186 +1,186 @@
 <?php
 
 final class DifferentialCreateDiffConduitAPIMethod
   extends DifferentialConduitAPIMethod {
 
   public function getAPIMethodName() {
     return 'differential.creatediff';
   }
 
   public function getMethodDescription() {
     return 'Create a new Differential diff.';
   }
 
   public function defineParamTypes() {
 
     $vcs_const = $this->formatStringConstants(
       array(
         'svn',
         'git',
         'hg',
       ));
 
     $status_const = $this->formatStringConstants(
       array(
         'none',
         'skip',
         'okay',
         'warn',
         'fail',
         'postponed',
       ));
 
     return array(
       'changes'                   => 'required list<dict>',
       'sourceMachine'             => 'required string',
       'sourcePath'                => 'required string',
       'branch'                    => 'required string',
       'bookmark'                  => 'optional string',
       'sourceControlSystem'       => 'required '.$vcs_const,
       'sourceControlPath'         => 'required string',
       'sourceControlBaseRevision' => 'required string',
       'creationMethod'            => 'optional string',
       'arcanistProject'           => 'optional string',
       'lintStatus'                => 'required '.$status_const,
       'unitStatus'                => 'required '.$status_const,
       'repositoryPHID'            => 'optional phid',
 
       'parentRevisionID'          => 'deprecated',
       'authorPHID'                => 'deprecated',
       'repositoryUUID'            => 'deprecated',
     );
   }
 
   public function defineReturnType() {
     return 'nonempty dict';
   }
 
   public function defineErrorTypes() {
     return array(
     );
   }
 
   protected function execute(ConduitAPIRequest $request) {
     $viewer = $request->getUser();
     $change_data = $request->getValue('changes');
 
     $changes = array();
     foreach ($change_data as $dict) {
       $changes[] = ArcanistDiffChange::newFromDictionary($dict);
     }
 
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges($viewer, $changes);
 
     // TODO: Remove repository UUID eventually; for now continue writing
     // the UUID. Note that we'll overwrite it below if we identify a
     // repository, and `arc` no longer sends it. This stuff is retained for
     // backward compatibility.
 
     $repository_uuid = $request->getValue('repositoryUUID');
     $repository_phid = $request->getValue('repositoryPHID');
     if ($repository_phid) {
       $repository = id(new PhabricatorRepositoryQuery())
         ->setViewer($viewer)
         ->withPHIDs(array($repository_phid))
         ->executeOne();
       if ($repository) {
         $repository_phid = $repository->getPHID();
         $repository_uuid = $repository->getUUID();
       }
     }
 
     $project_name = $request->getValue('arcanistProject');
     $project_phid = null;
     if ($project_name) {
       $arcanist_project = id(new PhabricatorRepositoryArcanistProject())
         ->loadOneWhere(
           'name = %s',
           $project_name);
       if (!$arcanist_project) {
         $arcanist_project = new PhabricatorRepositoryArcanistProject();
         $arcanist_project->setName($project_name);
         $arcanist_project->save();
       }
       $project_phid = $arcanist_project->getPHID();
     }
 
     switch ($request->getValue('lintStatus')) {
       case 'skip':
         $lint_status = DifferentialLintStatus::LINT_SKIP;
         break;
       case 'okay':
         $lint_status = DifferentialLintStatus::LINT_OKAY;
         break;
       case 'warn':
         $lint_status = DifferentialLintStatus::LINT_WARN;
         break;
       case 'fail':
         $lint_status = DifferentialLintStatus::LINT_FAIL;
         break;
       case 'postponed':
         $lint_status = DifferentialLintStatus::LINT_POSTPONED;
         break;
       case 'none':
       default:
         $lint_status = DifferentialLintStatus::LINT_NONE;
         break;
     }
 
     switch ($request->getValue('unitStatus')) {
       case 'skip':
         $unit_status = DifferentialUnitStatus::UNIT_SKIP;
         break;
       case 'okay':
         $unit_status = DifferentialUnitStatus::UNIT_OKAY;
         break;
       case 'warn':
         $unit_status = DifferentialUnitStatus::UNIT_WARN;
         break;
       case 'fail':
         $unit_status = DifferentialUnitStatus::UNIT_FAIL;
         break;
       case 'postponed':
         $unit_status = DifferentialUnitStatus::UNIT_POSTPONED;
         break;
       case 'none':
       default:
         $unit_status = DifferentialUnitStatus::UNIT_NONE;
         break;
     }
 
     $diff_data_dict = array(
       'sourcePath' => $request->getValue('sourcePath'),
       'sourceMachine' => $request->getValue('sourceMachine'),
       'branch' => $request->getValue('branch'),
       'creationMethod' => $request->getValue('creationMethod'),
       'authorPHID' => $viewer->getPHID(),
       'bookmark' => $request->getValue('bookmark'),
       'repositoryUUID' => $repository_uuid,
       'repositoryPHID' => $repository_phid,
       'sourceControlSystem' => $request->getValue('sourceControlSystem'),
       'sourceControlPath' => $request->getValue('sourceControlPath'),
       'sourceControlBaseRevision' =>
         $request->getValue('sourceControlBaseRevision'),
       'arcanistProjectPHID' => $project_phid,
       'lintStatus' => $lint_status,
       'unitStatus' => $unit_status,);
 
     $xactions = array(id(new DifferentialTransaction())
       ->setTransactionType(DifferentialDiffTransaction::TYPE_DIFF_CREATE)
       ->setNewValue($diff_data_dict),);
 
     id(new DifferentialDiffEditor())
       ->setActor($viewer)
       ->setContentSourceFromConduitRequest($request)
       ->applyTransactions($diff, $xactions);
 
     $path = '/differential/diff/'.$diff->getID().'/';
     $uri = PhabricatorEnv::getURI($path);
 
     return array(
       'diffid' => $diff->getID(),
       'uri'    => $uri,
     );
   }
 
 }
diff --git a/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php b/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
index 68531ea6bc..29638b5396 100644
--- a/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
+++ b/src/applications/differential/conduit/DifferentialCreateRawDiffConduitAPIMethod.php
@@ -1,70 +1,77 @@
 <?php
 
 final class DifferentialCreateRawDiffConduitAPIMethod
   extends DifferentialConduitAPIMethod {
 
   public function getAPIMethodName() {
     return 'differential.createrawdiff';
   }
 
   public function getMethodDescription() {
     return pht('Create a new Differential diff from a raw diff source.');
   }
 
   public function defineParamTypes() {
     return array(
       'diff' => 'required string',
       'repositoryPHID' => 'optional string',
+      'viewPolicy' => 'optional string',
     );
   }
 
   public function defineReturnType() {
     return 'nonempty dict';
   }
 
   public function defineErrorTypes() {
     return array(
     );
   }
 
   protected function execute(ConduitAPIRequest $request) {
     $viewer = $request->getUser();
     $raw_diff = $request->getValue('diff');
 
     $repository_phid = $request->getValue('repositoryPHID');
     if ($repository_phid) {
       $repository = id(new PhabricatorRepositoryQuery())
         ->setViewer($viewer)
         ->withPHIDs(array($repository_phid))
         ->executeOne();
       if (!$repository) {
         throw new Exception(
           pht('No such repository "%s"!', $repository_phid));
       }
     }
 
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($raw_diff);
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges($viewer, $changes);
 
     $diff_data_dict = array(
       'creationMethod' => 'web',
       'authorPHID' => $viewer->getPHID(),
       'repositoryPHID' => $repository_phid,
       'lintStatus' => DifferentialLintStatus::LINT_SKIP,
       'unitStatus' => DifferentialUnitStatus::UNIT_SKIP,);
 
     $xactions = array(id(new DifferentialTransaction())
       ->setTransactionType(DifferentialDiffTransaction::TYPE_DIFF_CREATE)
       ->setNewValue($diff_data_dict),);
 
+    if ($request->getValue('viewPolicy')) {
+      $xactions[] = id(new DifferentialTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_VIEW_POLICY)
+        ->setNewValue($request->getValue('viewPolicy'));
+    }
+
     id(new DifferentialDiffEditor())
       ->setActor($viewer)
       ->setContentSourceFromConduitRequest($request)
       ->setLookupRepository(false) // respect user choice
       ->applyTransactions($diff, $xactions);
 
     return $this->buildDiffInfoDictionary($diff);
   }
 
 }
diff --git a/src/applications/differential/controller/DifferentialDiffCreateController.php b/src/applications/differential/controller/DifferentialDiffCreateController.php
index c092597fbb..9c3698e3f2 100644
--- a/src/applications/differential/controller/DifferentialDiffCreateController.php
+++ b/src/applications/differential/controller/DifferentialDiffCreateController.php
@@ -1,127 +1,143 @@
 <?php
 
 final class DifferentialDiffCreateController extends DifferentialController {
 
   public function processRequest() {
 
     $request = $this->getRequest();
+    $viewer = $request->getUser();
 
     $diff = null;
+    // This object is just for policy stuff
+    $diff_object = DifferentialDiff::initializeNewDiff($viewer);
     $repository_phid = null;
     $repository_value = array();
     $errors = array();
     $e_diff = null;
     $e_file = null;
     $validation_exception = null;
     if ($request->isFormPost()) {
 
       $repository_tokenizer = $request->getArr(
         id(new DifferentialRepositoryField())->getFieldKey());
       if ($repository_tokenizer) {
         $repository_phid = reset($repository_tokenizer);
       }
 
       if ($request->getFileExists('diff-file')) {
         $diff = PhabricatorFile::readUploadedFileData($_FILES['diff-file']);
       } else {
         $diff = $request->getStr('diff');
       }
 
       if (!strlen($diff)) {
         $errors[] = pht(
           'You can not create an empty diff. Copy/paste a diff, or upload a '.
           'diff file.');
         $e_diff = pht('Required');
         $e_file = pht('Required');
       }
 
       if (!$errors) {
         try {
           $call = new ConduitCall(
             'differential.createrawdiff',
             array(
               'diff' => $diff,
-              'repositoryPHID' => $repository_phid,));
-          $call->setUser($request->getUser());
+              'repositoryPHID' => $repository_phid,
+              'viewPolicy' => $request->getStr('viewPolicy'),));
+          $call->setUser($viewer);
           $result = $call->execute();
           $path = id(new PhutilURI($result['uri']))->getPath();
           return id(new AphrontRedirectResponse())->setURI($path);
         } catch (PhabricatorApplicationTransactionValidationException $ex) {
           $validation_exception = $ex;
         }
       }
     }
 
     $form = new AphrontFormView();
     $arcanist_href = PhabricatorEnv::getDoclink('Arcanist User Guide');
     $arcanist_link = phutil_tag(
       'a',
       array(
         'href' => $arcanist_href,
         'target' => '_blank',
       ),
       'Arcanist');
 
     $cancel_uri = $this->getApplicationURI();
 
     if ($repository_phid) {
       $repository_value = $this->loadViewerHandles(array($repository_phid));
     }
 
+    $policies = id(new PhabricatorPolicyQuery())
+      ->setViewer($viewer)
+      ->setObject($diff_object)
+      ->execute();
+
     $form
       ->setAction('/differential/diff/create/')
       ->setEncType('multipart/form-data')
-      ->setUser($request->getUser())
+      ->setUser($viewer)
       ->appendInstructions(
         pht(
           'The best way to create a Differential diff is by using %s, but you '.
           'can also just paste a diff (for example, from %s, %s or %s) into '.
           'this box, or upload a diff file.',
           $arcanist_link,
           phutil_tag('tt', array(), 'svn diff'),
           phutil_tag('tt', array(), 'git diff'),
           phutil_tag('tt', array(), 'hg diff --git')))
       ->appendChild(
         id(new AphrontFormTextAreaControl())
           ->setLabel(pht('Raw Diff'))
           ->setName('diff')
           ->setValue($diff)
           ->setHeight(AphrontFormTextAreaControl::HEIGHT_VERY_TALL)
           ->setError($e_diff))
       ->appendChild(
         id(new AphrontFormFileControl())
           ->setLabel(pht('Raw Diff From File'))
           ->setName('diff-file')
           ->setError($e_file))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
         ->setName(id(new DifferentialRepositoryField())->getFieldKey())
         ->setLabel(pht('Repository'))
         ->setDatasource(new DiffusionRepositoryDatasource())
         ->setValue($repository_value)
         ->setLimit(1))
+      ->appendChild(
+        id(new AphrontFormPolicyControl())
+        ->setUser($viewer)
+        ->setName('viewPolicy')
+        ->setPolicyObject($diff_object)
+        ->setPolicies($policies)
+        ->setCapability(PhabricatorPolicyCapability::CAN_VIEW))
       ->appendChild(
         id(new AphrontFormSubmitControl())
           ->addCancelButton($cancel_uri)
           ->setValue(pht('Create Diff')));
 
     $form_box = id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Create New Diff'))
       ->setValidationException($validation_exception)
       ->setForm($form)
       ->setFormErrors($errors);
 
     $crumbs = $this->buildApplicationCrumbs();
     $crumbs->addTextCrumb(pht('Create Diff'));
 
     return $this->buildApplicationPage(
       array(
         $crumbs,
         $form_box,
       ),
       array(
         'title' => pht('Create Diff'),
       ));
   }
 
 }
diff --git a/src/applications/differential/controller/DifferentialRevisionEditController.php b/src/applications/differential/controller/DifferentialRevisionEditController.php
index 14bcdf0476..ea26693454 100644
--- a/src/applications/differential/controller/DifferentialRevisionEditController.php
+++ b/src/applications/differential/controller/DifferentialRevisionEditController.php
@@ -1,203 +1,210 @@
 <?php
 
 final class DifferentialRevisionEditController
   extends DifferentialController {
 
   private $id;
 
   public function willProcessRequest(array $data) {
     $this->id = idx($data, 'id');
   }
 
   public function processRequest() {
     $request = $this->getRequest();
     $viewer = $request->getUser();
 
     if (!$this->id) {
       $this->id = $request->getInt('revisionID');
     }
 
     if ($this->id) {
       $revision = id(new DifferentialRevisionQuery())
         ->setViewer($viewer)
         ->withIDs(array($this->id))
         ->needRelationships(true)
         ->needReviewerStatus(true)
         ->needActiveDiffs(true)
         ->requireCapabilities(
           array(
             PhabricatorPolicyCapability::CAN_VIEW,
             PhabricatorPolicyCapability::CAN_EDIT,
           ))
         ->executeOne();
       if (!$revision) {
         return new Aphront404Response();
       }
     } else {
       $revision = DifferentialRevision::initializeNewRevision($viewer);
       $revision->attachReviewerStatus(array());
     }
 
     $diff_id = $request->getInt('diffID');
     if ($diff_id) {
       $diff = id(new DifferentialDiffQuery())
         ->setViewer($viewer)
         ->withIDs(array($diff_id))
         ->executeOne();
       if (!$diff) {
         return new Aphront404Response();
       }
       if ($diff->getRevisionID()) {
         // TODO: Redirect?
         throw new Exception('This diff is already attached to a revision!');
       }
     } else {
       $diff = null;
     }
 
     if (!$diff) {
       if (!$revision->getID()) {
         throw new Exception(
           pht('You can not create a new revision without a diff!'));
       }
     } else {
       // TODO: It would be nice to show the diff being attached in the UI.
     }
 
     $field_list = PhabricatorCustomField::getObjectFields(
       $revision,
       PhabricatorCustomField::ROLE_EDIT);
     $field_list
       ->setViewer($viewer)
       ->readFieldsFromStorage($revision);
 
     if ($request->getStr('viaDiffView') && $diff) {
       $repo_key = id(new DifferentialRepositoryField())->getFieldKey();
       $repository_field = idx(
         $field_list->getFields(),
         $repo_key);
       if ($repository_field) {
         $repository_field->setValue($request->getStr($repo_key));
       }
+      $view_policy_key = id(new DifferentialViewPolicyField())->getFieldKey();
+      $view_policy_field = idx(
+        $field_list->getFields(),
+        $view_policy_key);
+      if ($view_policy_field) {
+        $view_policy_field->setValue($diff->getViewPolicy());
+      }
     }
 
     $validation_exception = null;
     if ($request->isFormPost() && !$request->getStr('viaDiffView')) {
 
       $editor = id(new DifferentialTransactionEditor())
         ->setActor($viewer)
         ->setContentSourceFromRequest($request)
         ->setContinueOnNoEffect(true);
 
       $xactions = $field_list->buildFieldTransactionsFromRequest(
         new DifferentialTransaction(),
         $request);
 
       if ($diff) {
         $repository_phid = null;
         $repository_tokenizer = $request->getArr(
           id(new DifferentialRepositoryField())->getFieldKey());
         if ($repository_tokenizer) {
           $repository_phid = reset($repository_tokenizer);
         }
 
         $xactions[] = id(new DifferentialTransaction())
           ->setTransactionType(DifferentialTransaction::TYPE_UPDATE)
           ->setNewValue($diff->getPHID());
 
         $editor->setRepositoryPHIDOverride($repository_phid);
       }
 
       $comments = $request->getStr('comments');
       if (strlen($comments)) {
         $xactions[] = id(new DifferentialTransaction())
           ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
           ->attachComment(
             id(new DifferentialTransactionComment())
               ->setContent($comments));
       }
 
       try {
         $editor->applyTransactions($revision, $xactions);
         $revision_uri = '/D'.$revision->getID();
         return id(new AphrontRedirectResponse())->setURI($revision_uri);
       } catch (PhabricatorApplicationTransactionValidationException $ex) {
         $validation_exception = $ex;
       }
     }
 
 
     $form = new AphrontFormView();
     $form->setUser($request->getUser());
     if ($diff) {
       $form->addHiddenInput('diffID', $diff->getID());
     }
 
     if ($revision->getID()) {
       $form->setAction('/differential/revision/edit/'.$revision->getID().'/');
     } else {
       $form->setAction('/differential/revision/edit/');
     }
 
     if ($diff && $revision->getID()) {
       $form
         ->appendChild(
           id(new AphrontFormTextAreaControl())
             ->setLabel(pht('Comments'))
             ->setName('comments')
             ->setCaption(pht("Explain what's new in this diff."))
             ->setValue($request->getStr('comments')))
         ->appendChild(
           id(new AphrontFormSubmitControl())
             ->setValue(pht('Save')))
         ->appendChild(
           id(new AphrontFormDividerControl()));
     }
 
     $field_list->appendFieldsToForm($form);
 
     $submit = id(new AphrontFormSubmitControl())
       ->setValue('Save');
     if ($diff) {
       $submit->addCancelButton('/differential/diff/'.$diff->getID().'/');
     } else {
       $submit->addCancelButton('/D'.$revision->getID());
     }
 
     $form->appendChild($submit);
 
     $crumbs = $this->buildApplicationCrumbs();
     if ($revision->getID()) {
       if ($diff) {
         $title = pht('Update Differential Revision');
         $crumbs->addTextCrumb(
           'D'.$revision->getID(),
           '/differential/diff/'.$diff->getID().'/');
       } else {
         $title = pht('Edit Differential Revision');
         $crumbs->addTextCrumb(
           'D'.$revision->getID(),
           '/D'.$revision->getID());
       }
     } else {
       $title = pht('Create New Differential Revision');
     }
 
     $form_box = id(new PHUIObjectBoxView())
       ->setHeaderText($title)
       ->setValidationException($validation_exception)
       ->setForm($form);
 
     $crumbs->addTextCrumb($title);
 
     return $this->buildApplicationPage(
       array(
         $crumbs,
         $form_box,
       ),
       array(
         'title' => $title,
       ));
   }
 
 }
diff --git a/src/applications/differential/editor/DifferentialDiffEditor.php b/src/applications/differential/editor/DifferentialDiffEditor.php
index c2513dab7a..69125da1e1 100644
--- a/src/applications/differential/editor/DifferentialDiffEditor.php
+++ b/src/applications/differential/editor/DifferentialDiffEditor.php
@@ -1,242 +1,247 @@
 <?php
 
 final class DifferentialDiffEditor
   extends PhabricatorApplicationTransactionEditor {
 
   private $diffDataDict;
   private $lookupRepository = true;
 
   public function setLookupRepository($bool) {
     $this->lookupRepository = $bool;
     return $this;
   }
 
   public function getEditorApplicationClass() {
     return 'PhabricatorDifferentialApplication';
   }
 
   public function getEditorObjectsDescription() {
     return pht('Differential Diffs');
   }
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
+    $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = DifferentialDiffTransaction::TYPE_DIFF_CREATE;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialDiffTransaction::TYPE_DIFF_CREATE:
         return null;
     }
 
     return parent::getCustomTransactionOldValue($object, $xaction);
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialDiffTransaction::TYPE_DIFF_CREATE:
         $this->diffDataDict = $xaction->getNewValue();
         return true;
     }
 
     return parent::getCustomTransactionNewValue($object, $xaction);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialDiffTransaction::TYPE_DIFF_CREATE:
         $dict = $this->diffDataDict;
         $this->updateDiffFromDict($object, $dict);
         return;
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+        $object->setViewPolicy($xaction->getNewValue());
+        return;
     }
 
     return parent::applyCustomInternalTransaction($object, $xaction);
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialDiffTransaction::TYPE_DIFF_CREATE:
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return;
     }
 
     return parent::applyCustomExternalTransaction($object, $xaction);
     }
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     // If we didn't get an explicit `repositoryPHID` (which means the client
     // is old, or couldn't figure out which repository the working copy
     // belongs to), apply heuristics to try to figure it out.
 
     if ($this->lookupRepository && !$object->getRepositoryPHID()) {
       $repository = id(new DifferentialRepositoryLookup())
         ->setDiff($object)
         ->setViewer($this->getActor())
         ->lookupRepository();
       if ($repository) {
         $object->setRepositoryPHID($repository->getPHID());
         $object->setRepositoryUUID($repository->getUUID());
         $object->save();
       }
     }
 
     return $xactions;
   }
 
   /**
    * We run Herald as part of transaction validation because Herald can
    * block diff creation for Differential diffs. Its important to do this
    * separately so no Herald logs are saved; these logs could expose
    * information the Herald rules are inteneded to block.
    */
   protected function validateTransaction(
     PhabricatorLiskDAO $object,
     $type,
     array $xactions) {
 
     $errors = parent::validateTransaction($object, $type, $xactions);
 
     foreach ($xactions as $xaction) {
       switch ($type) {
         case DifferentialDiffTransaction::TYPE_DIFF_CREATE:
           $diff = clone $object;
           $diff = $this->updateDiffFromDict($diff, $xaction->getNewValue());
 
           $adapter = $this->buildHeraldAdapter($diff, $xactions);
           $adapter->setContentSource($this->getContentSource());
           $adapter->setIsNewObject($this->getIsNewObject());
 
           $engine = new HeraldEngine();
 
           $rules = $engine->loadRulesForAdapter($adapter);
           $rules = mpull($rules, null, 'getID');
 
           $effects = $engine->applyRules($rules, $adapter);
 
           $blocking_effect = null;
           foreach ($effects as $effect) {
             if ($effect->getAction() == HeraldAdapter::ACTION_BLOCK) {
               $blocking_effect = $effect;
               break;
             }
           }
 
           if ($blocking_effect) {
             $rule = idx($rules, $effect->getRuleID());
             if ($rule && strlen($rule->getName())) {
               $rule_name = $rule->getName();
             } else {
               $rule_name = pht('Unnamed Herald Rule');
             }
 
             $message = $effect->getTarget();
             if (!strlen($message)) {
               $message = pht('(None.)');
             }
 
             $errors[] = new PhabricatorApplicationTransactionValidationError(
               $type,
               pht('Rejected by Herald'),
               pht(
                 "Creation of this diff was rejected by Herald rule %s.\n".
                 "  Rule: %s\n".
                 "Reason: %s",
                 'H'.$effect->getRuleID(),
                 $rule_name,
                 $message));
           }
           break;
       }
     }
 
     return $errors;
   }
 
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
   protected function supportsSearch() {
     return false;
   }
 
 /* -(  Herald Integration  )------------------------------------------------- */
 
   /**
    * See @{method:validateTransaction}. The only Herald action is to block
    * the creation of Diffs. We thus have to be careful not to save any
    * data and do this validation very early.
    */
   protected function shouldApplyHeraldRules(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return false;
   }
 
   protected function buildHeraldAdapter(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $adapter = id(new HeraldDifferentialDiffAdapter())
       ->setDiff($object);
 
     return $adapter;
   }
 
   protected function didApplyHeraldRules(
     PhabricatorLiskDAO $object,
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
 
     $xactions = array();
     return $xactions;
   }
 
   private function updateDiffFromDict(DifferentialDiff $diff, $dict) {
     $diff
       ->setSourcePath(idx($dict, 'sourcePath'))
       ->setSourceMachine(idx($dict, 'sourceMachine'))
       ->setBranch(idx($dict, 'branch'))
       ->setCreationMethod(idx($dict, 'creationMethod'))
       ->setAuthorPHID(idx($dict, 'authorPHID', $this->getActor()))
       ->setBookmark(idx($dict, 'bookmark'))
       ->setRepositoryPHID(idx($dict, 'repositoryPHID'))
       ->setRepositoryUUID(idx($dict, 'repositoryUUID'))
       ->setSourceControlSystem(idx($dict, 'sourceControlSystem'))
       ->setSourceControlPath(idx($dict, 'sourceControlPath'))
       ->setSourceControlBaseRevision(idx($dict, 'sourceControlBaseRevision'))
       ->setLintStatus(idx($dict, 'lintStatus'))
       ->setUnitStatus(idx($dict, 'unitStatus'))
       ->setArcanistProjectPHID(idx($dict, 'arcanistProjectPHID'));
 
     return $diff;
   }
 }
diff --git a/src/applications/differential/parser/__tests__/DifferentialHunkParserTestCase.php b/src/applications/differential/parser/__tests__/DifferentialHunkParserTestCase.php
index dc4acb383b..111d6ba91f 100644
--- a/src/applications/differential/parser/__tests__/DifferentialHunkParserTestCase.php
+++ b/src/applications/differential/parser/__tests__/DifferentialHunkParserTestCase.php
@@ -1,289 +1,291 @@
 <?php
 
 final class DifferentialHunkParserTestCase extends PhabricatorTestCase {
 
   private function createComment() {
     $comment = new DifferentialInlineComment();
     return $comment;
   }
 
   private function createHunk(
     $old_offset,
     $old_len,
     $new_offset,
     $new_len,
     $changes) {
 
     $hunk = id(new DifferentialHunkModern())
       ->setOldOffset($old_offset)
       ->setOldLen($old_len)
       ->setNewOffset($new_offset)
       ->setNewLen($new_len)
       ->setChanges($changes);
 
     return $hunk;
   }
 
   // Returns a change that consists of a single hunk, starting at line 1.
   private function createSingleChange($old_lines, $new_lines, $changes) {
     return array(
       0 => $this->createHunk(1, $old_lines, 1, $new_lines, $changes),
     );
   }
 
   private function createHunksFromFile($name) {
     $data = Filesystem::readFile(dirname(__FILE__).'/data/'.$name);
 
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($data);
     if (count($changes) !== 1) {
       throw new Exception("Expected 1 changeset for '{$name}'!");
     }
 
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $changes);
     return head($diff->getChangesets())->getHunks();
   }
 
   public function testOneLineOldComment() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(1, 0, '-a');
     $context = $parser->makeContextDiff(
       $hunks,
       0,
       1,
       0,
       0);
     $this->assertEqual("@@ -1,1 @@\n-a", $context);
   }
 
   public function testOneLineNewComment() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(0, 1, '+a');
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       1,
       0,
       0);
     $this->assertEqual("@@ +1,1 @@\n+a", $context);
   }
 
   public function testCannotFindContext() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(0, 1, '+a');
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       2,
       0,
       0);
     $this->assertEqual('', $context);
   }
 
   public function testOverlapFromStartOfHunk() {
     $parser = new DifferentialHunkParser();
     $hunks = array(
       0 => $this->createHunk(23, 2, 42, 2, " 1\n 2"),
     );
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       41,
       1,
       0);
     $this->assertEqual("@@ -23,1 +42,1 @@\n 1", $context);
   }
 
   public function testOverlapAfterEndOfHunk() {
     $parser = new DifferentialHunkParser();
     $hunks = array(
       0 => $this->createHunk(23, 2, 42, 2, " 1\n 2"),
     );
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       43,
       1,
       0);
     $this->assertEqual("@@ -24,1 +43,1 @@\n 2", $context);
   }
 
   public function testInclusionOfNewFileInOldCommentFromStart() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(2, 3,
          "+n1\n".
          " e1/2\n".
          "-o2\n".
          "+n3\n");
     $context = $parser->makeContextDiff(
       $hunks,
       0,
       1,
       1,
       0);
     $this->assertEqual(
         "@@ -1,2 +2,1 @@\n".
         " e1/2\n".
         "-o2", $context);
   }
 
   public function testInclusionOfOldFileInNewCommentFromStart() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(2, 2,
          "-o1\n".
          " e2/1\n".
          "-o3\n".
          "+n2\n");
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       1,
       1,
       0);
     $this->assertEqual(
         "@@ -2,1 +1,2 @@\n".
         " e2/1\n".
         "+n2", $context);
   }
 
   public function testNoNewlineAtEndOfFile() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(0, 1,
         "+a\n".
         "\\No newline at end of file");
     // Note that this only works with additional context.
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       2,
       0,
       1);
     $this->assertEqual(
         "@@ +1,1 @@\n".
         "+a\n".
         "\\No newline at end of file", $context);
   }
 
   public function testMultiLineNewComment() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(7, 7,
         " e1\n".
         " e2\n".
         "-o3\n".
         "-o4\n".
         "+n3\n".
         " e5/4\n".
         " e6/5\n".
         "+n6\n".
         " e7\n");
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       2,
       4,
       0);
     $this->assertEqual(
         "@@ -2,5 +2,5 @@\n".
         " e2\n".
         "-o3\n".
         "-o4\n".
         "+n3\n".
         " e5/4\n".
         " e6/5\n".
         "+n6", $context);
   }
 
   public function testMultiLineOldComment() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(7, 7,
         " e1\n".
         " e2\n".
         "-o3\n".
         "-o4\n".
         "+n3\n".
         " e5/4\n".
         " e6/5\n".
         "+n6\n".
         " e7\n");
     $context = $parser->makeContextDiff(
       $hunks,
       0,
       2,
       4,
       0);
     $this->assertEqual(
         "@@ -2,5 +2,4 @@\n".
         " e2\n".
         "-o3\n".
         "-o4\n".
         "+n3\n".
         " e5/4\n".
         " e6/5", $context);
   }
 
   public function testInclusionOfNewFileInOldCommentFromStartWithContext() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(2, 3,
          "+n1\n".
          " e1/2\n".
          "-o2\n".
          "+n3\n");
     $context = $parser->makeContextDiff(
       $hunks,
       0,
       1,
       1,
       1);
     $this->assertEqual(
         "@@ -1,2 +1,2 @@\n".
         "+n1\n".
         " e1/2\n".
         "-o2", $context);
   }
 
   public function testInclusionOfOldFileInNewCommentFromStartWithContext() {
     $parser = new DifferentialHunkParser();
     $hunks = $this->createSingleChange(2, 2,
          "-o1\n".
          " e2/1\n".
          "-o3\n".
          "+n2\n");
     $context = $parser->makeContextDiff(
       $hunks,
       1,
       1,
       1,
       1);
     $this->assertEqual(
         "@@ -1,3 +1,2 @@\n".
         "-o1\n".
         " e2/1\n".
         "-o3\n".
         "+n2", $context);
   }
 
   public function testMissingContext() {
     $tests = array(
       'missing_context.diff' => array(
         4 => true,
       ),
       'missing_context_2.diff' => array(
         5 => true,
       ),
       'missing_context_3.diff' => array(
         4 => true,
         13 => true,
       ),
     );
 
     foreach ($tests as $name => $expect) {
       $hunks = $this->createHunksFromFile($name);
 
       $parser = new DifferentialHunkParser();
       $actual = $parser->getHunkStartLines($hunks);
 
       $this->assertEqual($expect, $actual, $name);
     }
   }
 
 }
diff --git a/src/applications/differential/query/DifferentialDiffQuery.php b/src/applications/differential/query/DifferentialDiffQuery.php
index f9666400f1..4fc3ffcdfe 100644
--- a/src/applications/differential/query/DifferentialDiffQuery.php
+++ b/src/applications/differential/query/DifferentialDiffQuery.php
@@ -1,157 +1,156 @@
 <?php
 
 final class DifferentialDiffQuery
   extends PhabricatorCursorPagedPolicyAwareQuery {
 
   private $ids;
   private $phids;
   private $revisionIDs;
   private $needChangesets = false;
   private $needArcanistProjects = false;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
     return $this;
   }
 
   public function withPHIDs(array $phids) {
     $this->phids = $phids;
     return $this;
   }
 
   public function withRevisionIDs(array $revision_ids) {
     $this->revisionIDs = $revision_ids;
     return $this;
   }
 
   public function needChangesets($bool) {
     $this->needChangesets = $bool;
     return $this;
   }
 
   public function needArcanistProjects($bool) {
     $this->needArcanistProjects = $bool;
     return $this;
   }
 
   public function loadPage() {
     $table = new DifferentialDiff();
     $conn_r = $table->establishConnection('r');
 
     $data = queryfx_all(
       $conn_r,
       'SELECT * FROM %T %Q %Q %Q',
       $table->getTableName(),
       $this->buildWhereClause($conn_r),
       $this->buildOrderClause($conn_r),
       $this->buildLimitClause($conn_r));
 
     return $table->loadAllFromArray($data);
   }
 
   public function willFilterPage(array $diffs) {
     $revision_ids = array_filter(mpull($diffs, 'getRevisionID'));
 
     $revisions = array();
     if ($revision_ids) {
       $revisions = id(new DifferentialRevisionQuery())
         ->setViewer($this->getViewer())
         ->withIDs($revision_ids)
         ->execute();
     }
 
     foreach ($diffs as $key => $diff) {
       if (!$diff->getRevisionID()) {
-        $diff->attachRevision(null);
         continue;
       }
 
       $revision = idx($revisions, $diff->getRevisionID());
       if ($revision) {
         $diff->attachRevision($revision);
         continue;
       }
 
       unset($diffs[$key]);
     }
 
 
     if ($diffs && $this->needChangesets) {
       $diffs = $this->loadChangesets($diffs);
     }
 
     if ($diffs && $this->needArcanistProjects) {
       $diffs = $this->loadArcanistProjects($diffs);
     }
 
     return $diffs;
   }
 
   private function loadChangesets(array $diffs) {
     id(new DifferentialChangesetQuery())
       ->setViewer($this->getViewer())
       ->setParentQuery($this)
       ->withDiffs($diffs)
       ->needAttachToDiffs(true)
       ->needHunks(true)
       ->execute();
 
     return $diffs;
   }
 
   private function loadArcanistProjects(array $diffs) {
     $phids = array_filter(mpull($diffs, 'getArcanistProjectPHID'));
     $projects = array();
     $project_map = array();
     if ($phids) {
       $projects = id(new PhabricatorRepositoryArcanistProject())
         ->loadAllWhere(
           'phid IN (%Ls)',
           $phids);
       $project_map = mpull($projects, null, 'getPHID');
     }
 
     foreach ($diffs as $diff) {
       $project = null;
       if ($diff->getArcanistProjectPHID()) {
         $project = idx($project_map, $diff->getArcanistProjectPHID());
       }
       $diff->attachArcanistProject($project);
     }
 
     return $diffs;
   }
 
   private function buildWhereClause(AphrontDatabaseConnection $conn_r) {
     $where = array();
 
     if ($this->ids) {
       $where[] = qsprintf(
         $conn_r,
         'id IN (%Ld)',
         $this->ids);
     }
 
     if ($this->phids) {
       $where[] = qsprintf(
         $conn_r,
         'phid IN (%Ls)',
         $this->phids);
     }
 
     if ($this->revisionIDs) {
       $where[] = qsprintf(
         $conn_r,
         'revisionID IN (%Ld)',
         $this->revisionIDs);
     }
 
     $where[] = $this->buildPagingClause($conn_r);
     return $this->formatWhereClause($where);
   }
 
   public function getQueryApplicationClass() {
     return 'PhabricatorDifferentialApplication';
   }
 
 }
diff --git a/src/applications/differential/storage/DifferentialDiff.php b/src/applications/differential/storage/DifferentialDiff.php
index d52df5c2ec..c16a9f85fd 100644
--- a/src/applications/differential/storage/DifferentialDiff.php
+++ b/src/applications/differential/storage/DifferentialDiff.php
@@ -1,446 +1,469 @@
 <?php
 
 final class DifferentialDiff
   extends DifferentialDAO
   implements
     PhabricatorPolicyInterface,
     HarbormasterBuildableInterface,
     PhabricatorApplicationTransactionInterface,
     PhabricatorDestructibleInterface {
 
   protected $revisionID;
   protected $authorPHID;
   protected $repositoryPHID;
 
   protected $sourceMachine;
   protected $sourcePath;
 
   protected $sourceControlSystem;
   protected $sourceControlBaseRevision;
   protected $sourceControlPath;
 
   protected $lintStatus;
   protected $unitStatus;
 
   protected $lineCount;
 
   protected $branch;
   protected $bookmark;
 
   protected $arcanistProjectPHID;
   protected $creationMethod;
   protected $repositoryUUID;
 
   protected $description;
 
+  protected $viewPolicy;
+
   private $unsavedChangesets = array();
   private $changesets = self::ATTACHABLE;
   private $arcanistProject = self::ATTACHABLE;
   private $revision = self::ATTACHABLE;
   private $properties = array();
 
   public function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_COLUMN_SCHEMA => array(
         'revisionID' => 'id?',
         'authorPHID' => 'phid?',
         'repositoryPHID' => 'phid?',
         'sourceMachine' => 'text255?',
         'sourcePath' => 'text255?',
         'sourceControlSystem' => 'text64?',
         'sourceControlBaseRevision' => 'text255?',
         'sourceControlPath' => 'text255?',
         'lintStatus' => 'uint32',
         'unitStatus' => 'uint32',
         'lineCount' => 'uint32',
         'branch' => 'text255?',
         'bookmark' => 'text255?',
         'arcanistProjectPHID' => 'phid?',
         'repositoryUUID' => 'text64?',
 
         // T6203/NULLABILITY
         // These should be non-null; all diffs should have a creation method
         // and the description should just be empty.
         'creationMethod' => 'text255?',
         'description' => 'text255?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'revisionID' => array(
           'columns' => array('revisionID'),
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       DifferentialDiffPHIDType::TYPECONST);
   }
 
   public function addUnsavedChangeset(DifferentialChangeset $changeset) {
     if ($this->changesets === null) {
       $this->changesets = array();
     }
     $this->unsavedChangesets[] = $changeset;
     $this->changesets[] = $changeset;
     return $this;
   }
 
   public function attachChangesets(array $changesets) {
     assert_instances_of($changesets, 'DifferentialChangeset');
     $this->changesets = $changesets;
     return $this;
   }
 
   public function getChangesets() {
     return $this->assertAttached($this->changesets);
   }
 
   public function loadChangesets() {
     if (!$this->getID()) {
       return array();
     }
     return id(new DifferentialChangeset())->loadAllWhere(
       'diffID = %d',
       $this->getID());
   }
 
   public function attachArcanistProject(
     PhabricatorRepositoryArcanistProject $project = null) {
     $this->arcanistProject = $project;
     return $this;
   }
 
   public function getArcanistProject() {
     return $this->assertAttached($this->arcanistProject);
   }
 
   public function getArcanistProjectName() {
     $name = '';
     if ($this->arcanistProject) {
       $project = $this->getArcanistProject();
       $name = $project->getName();
     }
     return $name;
   }
 
   public function save() {
     $this->openTransaction();
       $ret = parent::save();
       foreach ($this->unsavedChangesets as $changeset) {
         $changeset->setDiffID($this->getID());
         $changeset->save();
       }
     $this->saveTransaction();
     return $ret;
   }
 
-  public static function newFromRawChanges(array $changes) {
+  public static function initializeNewDiff(PhabricatorUser $actor) {
+    $app = id(new PhabricatorApplicationQuery())
+      ->setViewer($actor)
+      ->withClasses(array('PhabricatorDifferentialApplication'))
+      ->executeOne();
+    $view_policy = $app->getPolicy(
+      DifferentialDefaultViewCapability::CAPABILITY);
+
+    $diff = id(new DifferentialDiff())
+      ->setViewPolicy($view_policy);
+
+    return $diff;
+  }
+
+  public static function newFromRawChanges(
+    PhabricatorUser $actor,
+    array $changes) {
+
     assert_instances_of($changes, 'ArcanistDiffChange');
-    $diff = new DifferentialDiff();
 
+    $diff = self::initializeNewDiff($actor);
     // There may not be any changes; initialize the changesets list so that
     // we don't throw later when accessing it.
     $diff->attachChangesets(array());
 
     $lines = 0;
     foreach ($changes as $change) {
       if ($change->getType() == ArcanistDiffChangeType::TYPE_MESSAGE) {
         // If a user pastes a diff into Differential which includes a commit
         // message (e.g., they ran `git show` to generate it), discard that
         // change when constructing a DifferentialDiff.
         continue;
       }
 
       $changeset = new DifferentialChangeset();
       $add_lines = 0;
       $del_lines = 0;
       $first_line = PHP_INT_MAX;
       $hunks = $change->getHunks();
       if ($hunks) {
         foreach ($hunks as $hunk) {
           $dhunk = new DifferentialHunkModern();
           $dhunk->setOldOffset($hunk->getOldOffset());
           $dhunk->setOldLen($hunk->getOldLength());
           $dhunk->setNewOffset($hunk->getNewOffset());
           $dhunk->setNewLen($hunk->getNewLength());
           $dhunk->setChanges($hunk->getCorpus());
           $changeset->addUnsavedHunk($dhunk);
           $add_lines += $hunk->getAddLines();
           $del_lines += $hunk->getDelLines();
           $added_lines = $hunk->getChangedLines('new');
           if ($added_lines) {
             $first_line = min($first_line, head_key($added_lines));
           }
         }
         $lines += $add_lines + $del_lines;
       } else {
         // This happens when you add empty files.
         $changeset->attachHunks(array());
       }
 
       $metadata = $change->getAllMetadata();
       if ($first_line != PHP_INT_MAX) {
         $metadata['line:first'] = $first_line;
       }
 
       $changeset->setOldFile($change->getOldPath());
       $changeset->setFilename($change->getCurrentPath());
       $changeset->setChangeType($change->getType());
 
       $changeset->setFileType($change->getFileType());
       $changeset->setMetadata($metadata);
       $changeset->setOldProperties($change->getOldProperties());
       $changeset->setNewProperties($change->getNewProperties());
       $changeset->setAwayPaths($change->getAwayPaths());
       $changeset->setAddLines($add_lines);
       $changeset->setDelLines($del_lines);
 
       $diff->addUnsavedChangeset($changeset);
     }
     $diff->setLineCount($lines);
 
     $parser = new DifferentialChangesetParser();
     $changesets = $parser->detectCopiedCode(
       $diff->getChangesets(),
       $min_width = 30,
       $min_lines = 3);
     $diff->attachChangesets($changesets);
 
     return $diff;
   }
 
 
   public function getDiffDict() {
     $dict = array(
       'id' => $this->getID(),
       'revisionID' => $this->getRevisionID(),
       'dateCreated' => $this->getDateCreated(),
       'dateModified' => $this->getDateModified(),
       'sourceControlBaseRevision' => $this->getSourceControlBaseRevision(),
       'sourceControlPath' => $this->getSourceControlPath(),
       'sourceControlSystem' => $this->getSourceControlSystem(),
       'branch' => $this->getBranch(),
       'bookmark' => $this->getBookmark(),
       'creationMethod' => $this->getCreationMethod(),
       'description' => $this->getDescription(),
       'unitStatus' => $this->getUnitStatus(),
       'lintStatus' => $this->getLintStatus(),
       'changes' => array(),
       'properties' => array(),
       'projectName' => $this->getArcanistProjectName(),
     );
 
     $dict['changes'] = $this->buildChangesList();
 
     $properties = id(new DifferentialDiffProperty())->loadAllWhere(
       'diffID = %d',
       $this->getID());
     foreach ($properties as $property) {
       $dict['properties'][$property->getName()] = $property->getData();
 
       if ($property->getName() == 'local:commits') {
         foreach ($property->getData() as $commit) {
           $dict['authorName'] = $commit['author'];
           $dict['authorEmail'] = idx($commit, 'authorEmail');
           break;
         }
       }
     }
 
     return $dict;
   }
 
   public function buildChangesList() {
     $changes = array();
     foreach ($this->getChangesets() as $changeset) {
       $hunks = array();
       foreach ($changeset->getHunks() as $hunk) {
         $hunks[] = array(
           'oldOffset' => $hunk->getOldOffset(),
           'newOffset' => $hunk->getNewOffset(),
           'oldLength' => $hunk->getOldLen(),
           'newLength' => $hunk->getNewLen(),
           'addLines'  => null,
           'delLines'  => null,
           'isMissingOldNewline' => null,
           'isMissingNewNewline' => null,
           'corpus'    => $hunk->getChanges(),
         );
       }
       $change = array(
         'id'            => $changeset->getID(),
         'metadata'      => $changeset->getMetadata(),
         'oldPath'       => $changeset->getOldFile(),
         'currentPath'   => $changeset->getFilename(),
         'awayPaths'     => $changeset->getAwayPaths(),
         'oldProperties' => $changeset->getOldProperties(),
         'newProperties' => $changeset->getNewProperties(),
         'type'          => $changeset->getChangeType(),
         'fileType'      => $changeset->getFileType(),
         'commitHash'    => null,
         'addLines'      => $changeset->getAddLines(),
         'delLines'      => $changeset->getDelLines(),
         'hunks'         => $hunks,
       );
       $changes[] = $change;
     }
     return $changes;
   }
 
+  public function hasRevision() {
+    return $this->revision !== self::ATTACHABLE;
+  }
+
   public function getRevision() {
     return $this->assertAttached($this->revision);
   }
 
   public function attachRevision(DifferentialRevision $revision = null) {
     $this->revision = $revision;
     return $this;
   }
 
   public function attachProperty($key, $value) {
     $this->properties[$key] = $value;
     return $this;
   }
 
   public function getProperty($key) {
     return $this->assertAttachedKey($this->properties, $key);
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
     );
   }
 
   public function getPolicy($capability) {
-    if ($this->getRevision()) {
+    if ($this->hasRevision()) {
       return $this->getRevision()->getPolicy($capability);
     }
 
-    return PhabricatorPolicies::POLICY_USER;
+    return $this->viewPolicy;
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
-    if ($this->getRevision()) {
+    if ($this->hasRevision()) {
       return $this->getRevision()->hasAutomaticCapability($capability, $viewer);
     }
 
-    return false;
+    return ($this->getAuthorPHID() == $viewer->getPhid());
   }
 
   public function describeAutomaticCapability($capability) {
-    if ($this->getRevision()) {
+    if ($this->hasRevision()) {
       return pht(
         'This diff is attached to a revision, and inherits its policies.');
     }
-    return null;
+    return pht('The author of a diff can see it.');
   }
 
 
 
 /* -(  HarbormasterBuildableInterface  )------------------------------------- */
 
 
   public function getHarbormasterBuildablePHID() {
     return $this->getPHID();
   }
 
   public function getHarbormasterContainerPHID() {
     if ($this->getRevisionID()) {
       $revision = id(new DifferentialRevision())->load($this->getRevisionID());
       if ($revision) {
         return $revision->getPHID();
       }
     }
 
     return null;
   }
 
   public function getBuildVariables() {
     $results = array();
 
     $results['buildable.diff'] = $this->getID();
     $revision = $this->getRevision();
     $results['buildable.revision'] = $revision->getID();
     $repo = $revision->getRepository();
 
     if ($repo) {
       $results['repository.callsign'] = $repo->getCallsign();
       $results['repository.vcs'] = $repo->getVersionControlSystem();
       $results['repository.uri'] = $repo->getPublicCloneURI();
     }
 
     return $results;
   }
 
   public function getAvailableBuildVariables() {
     return array(
       'buildable.diff' =>
         pht('The differential diff ID, if applicable.'),
       'buildable.revision' =>
         pht('The differential revision ID, if applicable.'),
       'repository.callsign' =>
         pht('The callsign of the repository in Phabricator.'),
       'repository.vcs' =>
         pht('The version control system, either "svn", "hg" or "git".'),
       'repository.uri' =>
         pht('The URI to clone or checkout the repository from.'),
     );
   }
 
 
 /* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
 
 
   public function getApplicationTransactionEditor() {
     if (!$this->getRevisionID()) {
       return null;
     }
     return $this->getRevision()->getApplicationTransactionEditor();
   }
 
 
   public function getApplicationTransactionObject() {
     if (!$this->getRevisionID()) {
       return null;
     }
     return $this->getRevision();
   }
 
   public function getApplicationTransactionTemplate() {
     if (!$this->getRevisionID()) {
       return null;
     }
     return $this->getRevision()->getApplicationTransactionTemplate();
   }
 
 
 /* -(  PhabricatorDestructibleInterface  )----------------------------------- */
 
 
   public function destroyObjectPermanently(
     PhabricatorDestructionEngine $engine) {
 
     $this->openTransaction();
       $this->delete();
 
       foreach ($this->loadChangesets() as $changeset) {
         $changeset->delete();
       }
 
       $properties = id(new DifferentialDiffProperty())->loadAllWhere(
         'diffID = %d',
         $this->getID());
       foreach ($properties as $prop) {
         $prop->delete();
       }
 
     $this->saveTransaction();
   }
 
 }
diff --git a/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php b/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
index e9e21784e7..3f851d767c 100644
--- a/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
+++ b/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
@@ -1,55 +1,58 @@
 <?php
 
 final class DifferentialDiffTestCase extends ArcanistPhutilTestCase {
 
   public function testDetectCopiedCode() {
     $root = dirname(__FILE__).'/diff/';
     $parser = new ArcanistDiffParser();
 
     $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
       $parser->parseDiff(Filesystem::readFile($root.'lint_engine.diff')));
     $copies = idx(head($diff->getChangesets())->getMetadata(), 'copy:lines');
 
     $this->assertEqual(
       array_combine(range(237, 252), range(167, 182)),
       ipull($copies, 1));
   }
 
   public function testDetectSlowCopiedCode() {
     // This tests that the detector has a reasonable runtime when a diff
     // contains a very large number of identical lines. See T5041.
 
     $parser = new ArcanistDiffParser();
 
     $line = str_repeat('x', 60);
     $oline = '-'.$line."\n";
     $nline = '+'.$line."\n";
 
     $n = 1000;
     $oblock = str_repeat($oline, $n);
     $nblock = str_repeat($nline, $n);
 
     $raw_diff = <<<EODIFF
 diff --git a/dst b/dst
 new file mode 100644
 index 0000000..1234567
 --- /dev/null
 +++ b/dst
 @@ -0,0 +1,{$n} @@
 {$nblock}
 diff --git a/src b/src
 deleted file mode 100644
 index 123457..0000000
 --- a/src
 +++ /dev/null
 @@ -1,{$n} +0,0 @@
 {$oblock}
 EODIFF;
 
-    $diff = DifferentialDiff::newFromRawChanges($parser->parseDiff($raw_diff));
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $parser->parseDiff($raw_diff));
 
     $this->assertTrue(true);
   }
 
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionChangeController.php b/src/applications/diffusion/controller/DiffusionChangeController.php
index 37e1dfb02d..c510b403cd 100644
--- a/src/applications/diffusion/controller/DiffusionChangeController.php
+++ b/src/applications/diffusion/controller/DiffusionChangeController.php
@@ -1,163 +1,165 @@
 <?php
 
 final class DiffusionChangeController extends DiffusionController {
 
   public function shouldAllowPublic() {
     return true;
   }
 
   public function processRequest() {
     $drequest = $this->diffusionRequest;
     $viewer = $this->getRequest()->getUser();
 
     $content = array();
 
     $data = $this->callConduitWithDiffusionRequest(
       'diffusion.diffquery',
       array(
         'commit' => $drequest->getCommit(),
         'path' => $drequest->getPath(),
       ));
 
     $drequest->updateSymbolicCommit($data['effectiveCommit']);
 
     $raw_changes = ArcanistDiffChange::newFromConduit($data['changes']);
-    $diff = DifferentialDiff::newFromRawChanges($raw_changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      $viewer,
+      $raw_changes);
     $changesets = $diff->getChangesets();
     $changeset = reset($changesets);
 
     if (!$changeset) {
       // TODO: Refine this.
       return new Aphront404Response();
     }
 
     $repository = $drequest->getRepository();
     $callsign = $repository->getCallsign();
     $changesets = array(
       0 => $changeset,
     );
 
     $changeset_view = new DifferentialChangesetListView();
     $changeset_view->setTitle(pht('Change'));
     $changeset_view->setChangesets($changesets);
     $changeset_view->setVisibleChangesets($changesets);
     $changeset_view->setRenderingReferences(
       array(
         0 => $drequest->generateURI(array('action' => 'rendering-ref')),
       ));
 
     $raw_params = array(
       'action' => 'browse',
       'params' => array(
         'view' => 'raw',
       ),
     );
 
     $right_uri = $drequest->generateURI($raw_params);
     $raw_params['params']['before'] = $drequest->getStableCommit();
     $left_uri = $drequest->generateURI($raw_params);
     $changeset_view->setRawFileURIs($left_uri, $right_uri);
 
     $changeset_view->setRenderURI('/diffusion/'.$callsign.'/diff/');
     $changeset_view->setWhitespace(
       DifferentialChangesetParser::WHITESPACE_SHOW_ALL);
     $changeset_view->setUser($this->getRequest()->getUser());
 
     // TODO: This is pretty awkward, unify the CSS between Diffusion and
     // Differential better.
     require_celerity_resource('differential-core-view-css');
     $content[] = $changeset_view->render();
 
     $crumbs = $this->buildCrumbs(
       array(
         'branch' => true,
         'path'   => true,
         'view'   => 'change',
       ));
 
     $links = $this->renderPathLinks($drequest, $mode = 'browse');
 
     $header = id(new PHUIHeaderView())
       ->setHeader($links)
       ->setUser($viewer)
       ->setPolicyObject($drequest->getRepository());
     $actions = $this->buildActionView($drequest);
     $properties = $this->buildPropertyView($drequest, $actions);
 
     $object_box = id(new PHUIObjectBoxView())
       ->setHeader($header)
       ->addPropertyList($properties);
 
     return $this->buildApplicationPage(
       array(
         $crumbs,
         $object_box,
         $content,
       ),
       array(
         'title' => pht('Change'),
         'device' => false,
       ));
   }
 
   private function buildActionView(DiffusionRequest $drequest) {
     $viewer = $this->getRequest()->getUser();
 
     $view = id(new PhabricatorActionListView())
       ->setUser($viewer);
 
     $history_uri = $drequest->generateURI(
       array(
         'action' => 'history',
       ));
 
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('View History'))
         ->setHref($history_uri)
         ->setIcon('fa-clock-o'));
 
     $browse_uri = $drequest->generateURI(
       array(
         'action' => 'browse',
       ));
 
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Browse Content'))
         ->setHref($browse_uri)
         ->setIcon('fa-files-o'));
 
     return $view;
   }
 
   protected function buildPropertyView(
     DiffusionRequest $drequest,
     PhabricatorActionListView $actions) {
 
     $viewer = $this->getRequest()->getUser();
 
     $view = id(new PHUIPropertyListView())
       ->setUser($viewer)
       ->setActionList($actions);
 
     $stable_commit = $drequest->getStableCommit();
     $callsign = $drequest->getRepository()->getCallsign();
 
     $view->addProperty(
       pht('Commit'),
       phutil_tag(
         'a',
         array(
           'href' => $drequest->generateURI(
             array(
               'action' => 'commit',
               'commit' => $stable_commit,
             )),
         ),
         $drequest->getRepository()->formatCommitName($stable_commit)));
 
     return $view;
   }
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionCommitController.php b/src/applications/diffusion/controller/DiffusionCommitController.php
index 3e7308a56a..f4006f82c7 100644
--- a/src/applications/diffusion/controller/DiffusionCommitController.php
+++ b/src/applications/diffusion/controller/DiffusionCommitController.php
@@ -1,1108 +1,1109 @@
 <?php
 
 final class DiffusionCommitController extends DiffusionController {
 
   const CHANGES_LIMIT = 100;
 
   private $auditAuthorityPHIDs;
   private $highlightedAudits;
 
   public function shouldAllowPublic() {
     return true;
   }
 
   public function willProcessRequest(array $data) {
     // This controller doesn't use blob/path stuff, just pass the dictionary
     // in directly instead of using the AphrontRequest parsing mechanism.
     $data['user'] = $this->getRequest()->getUser();
     $drequest = DiffusionRequest::newFromDictionary($data);
     $this->diffusionRequest = $drequest;
   }
 
   public function processRequest() {
     $drequest = $this->getDiffusionRequest();
 
     $request = $this->getRequest();
     $user = $request->getUser();
 
     if ($request->getStr('diff')) {
       return $this->buildRawDiffResponse($drequest);
     }
 
     $repository = $drequest->getRepository();
     $callsign = $repository->getCallsign();
 
     $content = array();
     $commit = id(new DiffusionCommitQuery())
       ->setViewer($request->getUser())
       ->withRepository($repository)
       ->withIdentifiers(array($drequest->getCommit()))
       ->needCommitData(true)
       ->needAuditRequests(true)
       ->executeOne();
 
     $crumbs = $this->buildCrumbs(array(
       'commit' => true,
     ));
 
     if (!$commit) {
       $exists = $this->callConduitWithDiffusionRequest(
         'diffusion.existsquery',
         array('commit' => $drequest->getCommit()));
       if (!$exists) {
         return new Aphront404Response();
       }
 
       $error = id(new AphrontErrorView())
         ->setTitle(pht('Commit Still Parsing'))
         ->appendChild(
           pht(
             'Failed to load the commit because the commit has not been '.
             'parsed yet.'));
 
       return $this->buildApplicationPage(
         array(
           $crumbs,
           $error,
         ),
         array(
           'title' => pht('Commit Still Parsing'),
           'device' => false,
         ));
     }
 
 
     $top_anchor = id(new PhabricatorAnchorView())
       ->setAnchorName('top')
       ->setNavigationMarker(true);
 
     $audit_requests = $commit->getAudits();
     $this->auditAuthorityPHIDs =
       PhabricatorAuditCommentEditor::loadAuditPHIDsForUser($user);
 
     $commit_data = $commit->getCommitData();
     $is_foreign = $commit_data->getCommitDetail('foreign-svn-stub');
     $changesets = null;
     if ($is_foreign) {
       $subpath = $commit_data->getCommitDetail('svn-subpath');
 
       $error_panel = new AphrontErrorView();
       $error_panel->setTitle(pht('Commit Not Tracked'));
       $error_panel->setSeverity(AphrontErrorView::SEVERITY_WARNING);
       $error_panel->appendChild(
         pht("This Diffusion repository is configured to track only one ".
         "subdirectory of the entire Subversion repository, and this commit ".
         "didn't affect the tracked subdirectory ('%s'), so no ".
         "information is available.", $subpath));
       $content[] = $error_panel;
       $content[] = $top_anchor;
     } else {
       $engine = PhabricatorMarkupEngine::newDifferentialMarkupEngine();
       $engine->setConfig('viewer', $user);
 
       require_celerity_resource('phabricator-remarkup-css');
 
       $parents = $this->callConduitWithDiffusionRequest(
         'diffusion.commitparentsquery',
         array('commit' => $drequest->getCommit()));
 
       if ($parents) {
         $parents = id(new DiffusionCommitQuery())
           ->setViewer($user)
           ->withRepository($repository)
           ->withIdentifiers($parents)
           ->execute();
       }
 
       $headsup_view = id(new PHUIHeaderView())
         ->setHeader(nonempty($commit->getSummary(), pht('Commit Detail')));
 
       $headsup_actions = $this->renderHeadsupActionList($commit, $repository);
 
       $commit_properties = $this->loadCommitProperties(
         $commit,
         $commit_data,
         $parents,
         $audit_requests);
       $property_list = id(new PHUIPropertyListView())
         ->setHasKeyboardShortcuts(true)
         ->setUser($user)
         ->setObject($commit);
       foreach ($commit_properties as $key => $value) {
         $property_list->addProperty($key, $value);
       }
 
       $message = $commit_data->getCommitMessage();
 
       $revision = $commit->getCommitIdentifier();
       $message = $this->linkBugtraq($message);
 
       $message = $engine->markupText($message);
 
       $property_list->invokeWillRenderEvent();
       $property_list->setActionList($headsup_actions);
 
       $detail_list = new PHUIPropertyListView();
       $detail_list->addSectionHeader(
         pht('Description'),
         PHUIPropertyListView::ICON_SUMMARY);
       $detail_list->addTextContent(
         phutil_tag(
           'div',
           array(
             'class' => 'diffusion-commit-message phabricator-remarkup',
           ),
           $message));
       $content[] = $top_anchor;
 
       $object_box = id(new PHUIObjectBoxView())
         ->setHeader($headsup_view)
         ->addPropertyList($property_list)
         ->addPropertyList($detail_list);
 
       $content[] = $object_box;
     }
 
     $content[] = $this->buildComments($commit);
 
     $hard_limit = 1000;
 
     if ($commit->isImported()) {
       $change_query = DiffusionPathChangeQuery::newFromDiffusionRequest(
         $drequest);
       $change_query->setLimit($hard_limit + 1);
       $changes = $change_query->loadChanges();
     } else {
       $changes = array();
     }
 
     $was_limited = (count($changes) > $hard_limit);
     if ($was_limited) {
       $changes = array_slice($changes, 0, $hard_limit);
     }
 
     $content[] = $this->buildMergesTable($commit);
 
     $highlighted_audits = $commit->getAuthorityAudits(
       $user,
       $this->auditAuthorityPHIDs);
 
     $owners_paths = array();
     if ($highlighted_audits) {
       $packages = id(new PhabricatorOwnersPackage())->loadAllWhere(
         'phid IN (%Ls)',
         mpull($highlighted_audits, 'getAuditorPHID'));
       if ($packages) {
         $owners_paths = id(new PhabricatorOwnersPath())->loadAllWhere(
           'repositoryPHID = %s AND packageID IN (%Ld)',
           $repository->getPHID(),
           mpull($packages, 'getID'));
       }
     }
 
     $change_table = new DiffusionCommitChangeTableView();
     $change_table->setDiffusionRequest($drequest);
     $change_table->setPathChanges($changes);
     $change_table->setOwnersPaths($owners_paths);
 
     $count = count($changes);
 
     $bad_commit = null;
     if ($count == 0) {
       $bad_commit = queryfx_one(
         id(new PhabricatorRepository())->establishConnection('r'),
         'SELECT * FROM %T WHERE fullCommitName = %s',
         PhabricatorRepository::TABLE_BADCOMMIT,
         'r'.$callsign.$commit->getCommitIdentifier());
     }
 
     if ($bad_commit) {
       $content[] = $this->renderStatusMessage(
         pht('Bad Commit'),
         $bad_commit['description']);
     } else if ($is_foreign) {
       // Don't render anything else.
     } else if (!$commit->isImported()) {
       $content[] = $this->renderStatusMessage(
         pht('Still Importing...'),
         pht(
           'This commit is still importing. Changes will be visible once '.
           'the import finishes.'));
     } else if (!count($changes)) {
       $content[] = $this->renderStatusMessage(
         pht('Empty Commit'),
         pht(
           'This commit is empty and does not affect any paths.'));
     } else if ($was_limited) {
       $content[] = $this->renderStatusMessage(
         pht('Enormous Commit'),
         pht(
           'This commit is enormous, and affects more than %d files. '.
           'Changes are not shown.',
           $hard_limit));
     } else {
       // The user has clicked "Show All Changes", and we should show all the
       // changes inline even if there are more than the soft limit.
       $show_all_details = $request->getBool('show_all');
 
       $change_panel = new PHUIObjectBoxView();
       $header = new PHUIHeaderView();
       $header->setHeader('Changes ('.number_format($count).')');
       $change_panel->setID('toc');
       if ($count > self::CHANGES_LIMIT && !$show_all_details) {
 
         $icon = id(new PHUIIconView())
           ->setIconFont('fa-files-o');
 
         $button = id(new PHUIButtonView())
           ->setText(pht('Show All Changes'))
           ->setHref('?show_all=true')
           ->setTag('a')
           ->setIcon($icon);
 
         $warning_view = id(new AphrontErrorView())
           ->setSeverity(AphrontErrorView::SEVERITY_WARNING)
           ->setTitle('Very Large Commit')
           ->appendChild(
             pht('This commit is very large. Load each file individually.'));
 
         $change_panel->setErrorView($warning_view);
         $header->addActionLink($button);
       }
 
       $change_panel->appendChild($change_table);
       $change_panel->setHeader($header);
 
       $content[] = $change_panel;
 
       $changesets = DiffusionPathChange::convertToDifferentialChangesets(
+        $user,
         $changes);
 
       $vcs = $repository->getVersionControlSystem();
       switch ($vcs) {
         case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
           $vcs_supports_directory_changes = true;
           break;
         case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
           $vcs_supports_directory_changes = false;
           break;
         default:
           throw new Exception('Unknown VCS.');
       }
 
       $references = array();
       foreach ($changesets as $key => $changeset) {
         $file_type = $changeset->getFileType();
         if ($file_type == DifferentialChangeType::FILE_DIRECTORY) {
           if (!$vcs_supports_directory_changes) {
             unset($changesets[$key]);
             continue;
           }
         }
 
         $references[$key] = $drequest->generateURI(
           array(
             'action' => 'rendering-ref',
             'path'   => $changeset->getFilename(),
           ));
       }
 
       // TODO: Some parts of the views still rely on properties of the
       // DifferentialChangeset. Make the objects ephemeral to make sure we don't
       // accidentally save them, and then set their ID to the appropriate ID for
       // this application (the path IDs).
       $path_ids = array_flip(mpull($changes, 'getPath'));
       foreach ($changesets as $changeset) {
         $changeset->makeEphemeral();
         $changeset->setID($path_ids[$changeset->getFilename()]);
       }
 
       if ($count <= self::CHANGES_LIMIT || $show_all_details) {
         $visible_changesets = $changesets;
       } else {
         $visible_changesets = array();
         $inlines = PhabricatorAuditInlineComment::loadDraftAndPublishedComments(
           $user,
           $commit->getPHID());
         $path_ids = mpull($inlines, null, 'getPathID');
         foreach ($changesets as $key => $changeset) {
           if (array_key_exists($changeset->getID(), $path_ids)) {
             $visible_changesets[$key] = $changeset;
           }
         }
       }
 
       $change_list_title = DiffusionView::nameCommit(
         $repository,
         $commit->getCommitIdentifier());
       $change_list = new DifferentialChangesetListView();
       $change_list->setTitle($change_list_title);
       $change_list->setChangesets($changesets);
       $change_list->setVisibleChangesets($visible_changesets);
       $change_list->setRenderingReferences($references);
       $change_list->setRenderURI('/diffusion/'.$callsign.'/diff/');
       $change_list->setRepository($repository);
       $change_list->setUser($user);
 
       // TODO: Try to setBranch() to something reasonable here?
 
       $change_list->setStandaloneURI(
         '/diffusion/'.$callsign.'/diff/');
       $change_list->setRawFileURIs(
         // TODO: Implement this, somewhat tricky if there's an octopus merge
         // or whatever?
         null,
         '/diffusion/'.$callsign.'/diff/?view=r');
 
       $change_list->setInlineCommentControllerURI(
         '/diffusion/inline/edit/'.phutil_escape_uri($commit->getPHID()).'/');
 
       $change_references = array();
       foreach ($changesets as $key => $changeset) {
         $change_references[$changeset->getID()] = $references[$key];
       }
       $change_table->setRenderingReferences($change_references);
 
       $content[] = $change_list->render();
     }
 
     $content[] = $this->renderAddCommentPanel($commit, $audit_requests);
 
     $commit_id = 'r'.$callsign.$commit->getCommitIdentifier();
     $short_name = DiffusionView::nameCommit(
       $repository,
       $commit->getCommitIdentifier());
 
     $prefs = $user->loadPreferences();
     $pref_filetree = PhabricatorUserPreferences::PREFERENCE_DIFF_FILETREE;
     $pref_collapse = PhabricatorUserPreferences::PREFERENCE_NAV_COLLAPSED;
     $show_filetree = $prefs->getPreference($pref_filetree);
     $collapsed = $prefs->getPreference($pref_collapse);
 
     if ($changesets && $show_filetree) {
       $nav = id(new DifferentialChangesetFileTreeSideNavBuilder())
         ->setAnchorName('top')
         ->setTitle($short_name)
         ->setBaseURI(new PhutilURI('/'.$commit_id))
         ->build($changesets)
         ->setCrumbs($crumbs)
         ->setCollapsed((bool)$collapsed)
         ->appendChild($content);
       $content = $nav;
     } else {
       $content = array($crumbs, $content);
     }
 
     return $this->buildApplicationPage(
       $content,
       array(
         'title' => $commit_id,
         'pageObjects' => array($commit->getPHID()),
         'device' => false,
       ));
   }
 
   private function loadCommitProperties(
     PhabricatorRepositoryCommit $commit,
     PhabricatorRepositoryCommitData $data,
     array $parents,
     array $audit_requests) {
 
     assert_instances_of($parents, 'PhabricatorRepositoryCommit');
     $viewer = $this->getRequest()->getUser();
     $commit_phid = $commit->getPHID();
     $drequest = $this->getDiffusionRequest();
     $repository = $drequest->getRepository();
 
     $edge_query = id(new PhabricatorEdgeQuery())
       ->withSourcePHIDs(array($commit_phid))
       ->withEdgeTypes(array(
         DiffusionCommitHasTaskEdgeType::EDGECONST,
         PhabricatorEdgeConfig::TYPE_COMMIT_HAS_PROJECT,
         PhabricatorEdgeConfig::TYPE_COMMIT_HAS_DREV,
       ));
 
     $edges = $edge_query->execute();
 
     $task_phids = array_keys(
       $edges[$commit_phid][DiffusionCommitHasTaskEdgeType::EDGECONST]);
     $proj_phids = array_keys(
       $edges[$commit_phid][PhabricatorEdgeConfig::TYPE_COMMIT_HAS_PROJECT]);
     $revision_phid = key(
       $edges[$commit_phid][PhabricatorEdgeConfig::TYPE_COMMIT_HAS_DREV]);
 
     $phids = $edge_query->getDestinationPHIDs(array($commit_phid));
 
     if ($data->getCommitDetail('authorPHID')) {
       $phids[] = $data->getCommitDetail('authorPHID');
     }
     if ($data->getCommitDetail('reviewerPHID')) {
       $phids[] = $data->getCommitDetail('reviewerPHID');
     }
     if ($data->getCommitDetail('committerPHID')) {
       $phids[] = $data->getCommitDetail('committerPHID');
     }
     if ($parents) {
       foreach ($parents as $parent) {
         $phids[] = $parent->getPHID();
       }
     }
 
     // NOTE: We should never normally have more than a single push log, but
     // it can occur naturally if a commit is pushed, then the branch it was
     // on is deleted, then the commit is pushed again (or through other similar
     // chains of events). This should be rare, but does not indicate a bug
     // or data issue.
 
     // NOTE: We never query push logs in SVN because the commiter is always
     // the pusher and the commit time is always the push time; the push log
     // is redundant and we save a query by skipping it.
 
     $push_logs = array();
     if ($repository->isHosted() && !$repository->isSVN()) {
       $push_logs = id(new PhabricatorRepositoryPushLogQuery())
         ->setViewer($viewer)
         ->withRepositoryPHIDs(array($repository->getPHID()))
         ->withNewRefs(array($commit->getCommitIdentifier()))
         ->withRefTypes(array(PhabricatorRepositoryPushLog::REFTYPE_COMMIT))
         ->execute();
       foreach ($push_logs as $log) {
         $phids[] = $log->getPusherPHID();
       }
     }
 
     $handles = array();
     if ($phids) {
       $handles = $this->loadViewerHandles($phids);
     }
 
     $props = array();
 
     if ($commit->getAuditStatus()) {
       $status = PhabricatorAuditCommitStatusConstants::getStatusName(
         $commit->getAuditStatus());
       $tag = id(new PHUITagView())
         ->setType(PHUITagView::TYPE_STATE)
         ->setName($status);
 
       switch ($commit->getAuditStatus()) {
         case PhabricatorAuditCommitStatusConstants::NEEDS_AUDIT:
           $tag->setBackgroundColor(PHUITagView::COLOR_ORANGE);
           break;
         case PhabricatorAuditCommitStatusConstants::CONCERN_RAISED:
           $tag->setBackgroundColor(PHUITagView::COLOR_RED);
           break;
         case PhabricatorAuditCommitStatusConstants::PARTIALLY_AUDITED:
           $tag->setBackgroundColor(PHUITagView::COLOR_BLUE);
           break;
         case PhabricatorAuditCommitStatusConstants::FULLY_AUDITED:
           $tag->setBackgroundColor(PHUITagView::COLOR_GREEN);
           break;
       }
 
       $props['Status'] = $tag;
     }
 
     if ($audit_requests) {
       $user_requests = array();
       $other_requests = array();
       foreach ($audit_requests as $audit_request) {
         if ($audit_request->isUser()) {
           $user_requests[] = $audit_request;
         } else {
           $other_requests[] = $audit_request;
         }
       }
 
       if ($user_requests) {
         $props['Auditors'] = $this->renderAuditStatusView(
           $user_requests);
       }
 
       if ($other_requests) {
         $props['Project/Package Auditors'] = $this->renderAuditStatusView(
           $other_requests);
       }
     }
 
     $author_phid = $data->getCommitDetail('authorPHID');
     $author_name = $data->getAuthorName();
 
     if (!$repository->isSVN()) {
       $authored_info = id(new PHUIStatusItemView());
       // TODO: In Git, a distinct authorship date is available. When present,
       // we should show it here.
 
       if ($author_phid) {
         $authored_info->setTarget($handles[$author_phid]->renderLink());
       } else if (strlen($author_name)) {
         $authored_info->setTarget($author_name);
       }
 
       $props['Authored'] = id(new PHUIStatusListView())
         ->addItem($authored_info);
     }
 
     $committed_info = id(new PHUIStatusItemView())
       ->setNote(phabricator_datetime($commit->getEpoch(), $viewer));
 
     $committer_phid = $data->getCommitDetail('committerPHID');
     $committer_name = $data->getCommitDetail('committer');
     if ($committer_phid) {
       $committed_info->setTarget($handles[$committer_phid]->renderLink());
     } else if (strlen($committer_name)) {
       $committed_info->setTarget($committer_name);
     } else if ($author_phid) {
       $committed_info->setTarget($handles[$author_phid]->renderLink());
     } else if (strlen($author_name)) {
       $committed_info->setTarget($author_name);
     }
 
     $props['Committed'] = id(new PHUIStatusListView())
       ->addItem($committed_info);
 
     if ($push_logs) {
       $pushed_list = new PHUIStatusListView();
 
       foreach ($push_logs as $push_log) {
         $pushed_item = id(new PHUIStatusItemView())
           ->setTarget($handles[$push_log->getPusherPHID()]->renderLink())
           ->setNote(phabricator_datetime($push_log->getEpoch(), $viewer));
         $pushed_list->addItem($pushed_item);
       }
 
       $props['Pushed'] = $pushed_list;
     }
 
     $reviewer_phid = $data->getCommitDetail('reviewerPHID');
     if ($reviewer_phid) {
       $props['Reviewer'] = $handles[$reviewer_phid]->renderLink();
     }
 
     if ($revision_phid) {
       $props['Differential Revision'] = $handles[$revision_phid]->renderLink();
     }
 
     if ($parents) {
       $parent_links = array();
       foreach ($parents as $parent) {
         $parent_links[] = $handles[$parent->getPHID()]->renderLink();
       }
       $props['Parents'] = phutil_implode_html(" \xC2\xB7 ", $parent_links);
     }
 
     $props['Branches'] = phutil_tag(
       'span',
       array(
         'id' => 'commit-branches',
       ),
       pht('Unknown'));
     $props['Tags'] = phutil_tag(
       'span',
       array(
         'id' => 'commit-tags',
       ),
       pht('Unknown'));
 
     $callsign = $repository->getCallsign();
     $root = '/diffusion/'.$callsign.'/commit/'.$commit->getCommitIdentifier();
     Javelin::initBehavior(
       'diffusion-commit-branches',
       array(
         $root.'/branches/' => 'commit-branches',
         $root.'/tags/' => 'commit-tags',
       ));
 
     $refs = $this->buildRefs($drequest);
     if ($refs) {
       $props['References'] = $refs;
     }
 
     if ($task_phids) {
       $task_list = array();
       foreach ($task_phids as $phid) {
         $task_list[] = $handles[$phid]->renderLink();
       }
       $task_list = phutil_implode_html(phutil_tag('br'), $task_list);
       $props['Tasks'] = $task_list;
     }
 
     if ($proj_phids) {
       $proj_list = array();
       foreach ($proj_phids as $phid) {
         $proj_list[] = $handles[$phid]->renderLink();
       }
       $proj_list = phutil_implode_html(phutil_tag('br'), $proj_list);
       $props['Projects'] = $proj_list;
     }
 
     return $props;
   }
 
   private function buildComments(PhabricatorRepositoryCommit $commit) {
     $viewer = $this->getRequest()->getUser();
 
     $xactions = id(new PhabricatorAuditTransactionQuery())
       ->setViewer($viewer)
       ->withObjectPHIDs(array($commit->getPHID()))
       ->needComments(true)
       ->execute();
 
     $path_ids = array();
     foreach ($xactions as $xaction) {
       if ($xaction->hasComment()) {
         $path_id = $xaction->getComment()->getPathID();
         if ($path_id) {
           $path_ids[] = $path_id;
         }
       }
     }
 
     $path_map = array();
     if ($path_ids) {
       $path_map = id(new DiffusionPathQuery())
         ->withPathIDs($path_ids)
         ->execute();
       $path_map = ipull($path_map, 'path', 'id');
     }
 
     return id(new PhabricatorAuditTransactionView())
       ->setUser($viewer)
       ->setObjectPHID($commit->getPHID())
       ->setPathMap($path_map)
       ->setTransactions($xactions);
   }
 
   private function renderAddCommentPanel(
     PhabricatorRepositoryCommit $commit,
     array $audit_requests) {
     assert_instances_of($audit_requests, 'PhabricatorRepositoryAuditRequest');
 
     $request = $this->getRequest();
     $user = $request->getUser();
 
     if (!$user->isLoggedIn()) {
       return id(new PhabricatorApplicationTransactionCommentView())
         ->setUser($user)
         ->setRequestURI($request->getRequestURI());
     }
 
     $is_serious = PhabricatorEnv::getEnvConfig('phabricator.serious-business');
 
     $pane_id = celerity_generate_unique_node_id();
     Javelin::initBehavior(
       'differential-keyboard-navigation',
       array(
         'haunt' => $pane_id,
       ));
 
     $draft = id(new PhabricatorDraft())->loadOneWhere(
       'authorPHID = %s AND draftKey = %s',
       $user->getPHID(),
       'diffusion-audit-'.$commit->getID());
     if ($draft) {
       $draft = $draft->getDraft();
     } else {
       $draft = null;
     }
 
     $actions = $this->getAuditActions($commit, $audit_requests);
 
     $form = id(new AphrontFormView())
       ->setUser($user)
       ->setAction('/audit/addcomment/')
       ->addHiddenInput('commit', $commit->getPHID())
       ->appendChild(
         id(new AphrontFormSelectControl())
           ->setLabel(pht('Action'))
           ->setName('action')
           ->setID('audit-action')
           ->setOptions($actions))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Add Auditors'))
           ->setName('auditors')
           ->setControlID('add-auditors')
           ->setControlStyle('display: none')
           ->setID('add-auditors-tokenizer')
           ->setDisableBehavior(true))
       ->appendChild(
         id(new AphrontFormTokenizerControl())
           ->setLabel(pht('Add CCs'))
           ->setName('ccs')
           ->setControlID('add-ccs')
           ->setControlStyle('display: none')
           ->setID('add-ccs-tokenizer')
           ->setDisableBehavior(true))
       ->appendChild(
         id(new PhabricatorRemarkupControl())
           ->setLabel(pht('Comments'))
           ->setName('content')
           ->setValue($draft)
           ->setID('audit-content')
           ->setUser($user))
       ->appendChild(
         id(new AphrontFormSubmitControl())
           ->setValue(pht('Submit')));
 
     $header = new PHUIHeaderView();
     $header->setHeader(
       $is_serious ? pht('Audit Commit') : pht('Creative Accounting'));
 
     require_celerity_resource('phabricator-transaction-view-css');
 
     $mailable_source = new PhabricatorMetaMTAMailableDatasource();
     $auditor_source = new DiffusionAuditorDatasource();
 
     Javelin::initBehavior(
       'differential-add-reviewers-and-ccs',
       array(
         'dynamic' => array(
           'add-auditors-tokenizer' => array(
             'actions' => array('add_auditors' => 1),
             'src' => $auditor_source->getDatasourceURI(),
             'row' => 'add-auditors',
             'placeholder' => $auditor_source->getPlaceholderText(),
           ),
           'add-ccs-tokenizer' => array(
             'actions' => array('add_ccs' => 1),
             'src' => $mailable_source->getDatasourceURI(),
             'row' => 'add-ccs',
             'placeholder' => $mailable_source->getPlaceholderText(),
           ),
         ),
         'select' => 'audit-action',
       ));
 
     Javelin::initBehavior('differential-feedback-preview', array(
       'uri'       => '/audit/preview/'.$commit->getID().'/',
       'preview'   => 'audit-preview',
       'content'   => 'audit-content',
       'action'    => 'audit-action',
       'previewTokenizers' => array(
         'auditors' => 'add-auditors-tokenizer',
         'ccs'      => 'add-ccs-tokenizer',
       ),
       'inline'     => 'inline-comment-preview',
       'inlineuri'  => '/diffusion/inline/preview/'.$commit->getPHID().'/',
     ));
 
     $loading = phutil_tag_div(
       'aphront-panel-preview-loading-text',
       pht('Loading preview...'));
 
     $preview_panel = phutil_tag_div(
       'aphront-panel-preview aphront-panel-flush',
       array(
         phutil_tag('div', array('id' => 'audit-preview'), $loading),
         phutil_tag('div', array('id' => 'inline-comment-preview')),
       ));
 
     // TODO: This is pretty awkward, unify the CSS between Diffusion and
     // Differential better.
     require_celerity_resource('differential-core-view-css');
 
     $anchor = id(new PhabricatorAnchorView())
       ->setAnchorName('comment')
       ->setNavigationMarker(true)
       ->render();
 
     $comment_box = id(new PHUIObjectBoxView())
       ->setHeader($header)
       ->appendChild($form);
 
     return phutil_tag(
       'div',
       array(
         'id' => $pane_id,
       ),
       phutil_tag_div(
         'differential-add-comment-panel',
         array($anchor, $comment_box, $preview_panel)));
   }
 
   /**
    * Return a map of available audit actions for rendering into a <select />.
    * This shows the user valid actions, and does not show nonsense/invalid
    * actions (like closing an already-closed commit, or resigning from a commit
    * you have no association with).
    */
   private function getAuditActions(
     PhabricatorRepositoryCommit $commit,
     array $audit_requests) {
     assert_instances_of($audit_requests, 'PhabricatorRepositoryAuditRequest');
     $user = $this->getRequest()->getUser();
 
     $user_is_author = ($commit->getAuthorPHID() == $user->getPHID());
 
     $user_request = null;
     foreach ($audit_requests as $audit_request) {
       if ($audit_request->getAuditorPHID() == $user->getPHID()) {
         $user_request = $audit_request;
         break;
       }
     }
 
     $actions = array();
     $actions[PhabricatorAuditActionConstants::COMMENT] = true;
     $actions[PhabricatorAuditActionConstants::ADD_CCS] = true;
     $actions[PhabricatorAuditActionConstants::ADD_AUDITORS] = true;
 
     // We allow you to accept your own commits. A use case here is that you
     // notice an issue with your own commit and "Raise Concern" as an indicator
     // to other auditors that you're on top of the issue, then later resolve it
     // and "Accept". You can not accept on behalf of projects or packages,
     // however.
     $actions[PhabricatorAuditActionConstants::ACCEPT]  = true;
     $actions[PhabricatorAuditActionConstants::CONCERN] = true;
 
 
     // To resign, a user must have authority on some request and not be the
     // commit's author.
     if (!$user_is_author) {
       $may_resign = false;
 
       $authority_map = array_fill_keys($this->auditAuthorityPHIDs, true);
       foreach ($audit_requests as $request) {
         if (empty($authority_map[$request->getAuditorPHID()])) {
           continue;
         }
         $may_resign = true;
         break;
       }
 
       // If the user has already resigned, don't show "Resign...".
       $status_resigned = PhabricatorAuditStatusConstants::RESIGNED;
       if ($user_request) {
         if ($user_request->getAuditStatus() == $status_resigned) {
           $may_resign = false;
         }
       }
 
       if ($may_resign) {
         $actions[PhabricatorAuditActionConstants::RESIGN] = true;
       }
     }
 
     $status_concern = PhabricatorAuditCommitStatusConstants::CONCERN_RAISED;
     $concern_raised = ($commit->getAuditStatus() == $status_concern);
     $can_close_option = PhabricatorEnv::getEnvConfig(
       'audit.can-author-close-audit');
     if ($can_close_option && $user_is_author && $concern_raised) {
       $actions[PhabricatorAuditActionConstants::CLOSE] = true;
     }
 
     foreach ($actions as $constant => $ignored) {
       $actions[$constant] =
         PhabricatorAuditActionConstants::getActionName($constant);
     }
 
     return $actions;
   }
 
   private function buildMergesTable(PhabricatorRepositoryCommit $commit) {
     $drequest = $this->getDiffusionRequest();
     $limit = 50;
 
     $merges = array();
     try {
       $merges = $this->callConduitWithDiffusionRequest(
         'diffusion.mergedcommitsquery',
         array(
           'commit' => $drequest->getCommit(),
           'limit' => $limit + 1,
         ));
     } catch (ConduitException $ex) {
       if ($ex->getMessage() != 'ERR-UNSUPPORTED-VCS') {
         throw $ex;
       }
     }
 
     if (!$merges) {
       return null;
     }
 
     $caption = null;
     if (count($merges) > $limit) {
       $merges = array_slice($merges, 0, $limit);
       $caption =
         "This commit merges more than {$limit} changes. Only the first ".
         "{$limit} are shown.";
     }
 
     $history_table = new DiffusionHistoryTableView();
     $history_table->setUser($this->getRequest()->getUser());
     $history_table->setDiffusionRequest($drequest);
     $history_table->setHistory($merges);
     $history_table->loadRevisions();
 
     $phids = $history_table->getRequiredHandlePHIDs();
     $handles = $this->loadViewerHandles($phids);
     $history_table->setHandles($handles);
 
     $panel = new AphrontPanelView();
     $panel->setHeader(pht('Merged Changes'));
     $panel->setCaption($caption);
     $panel->appendChild($history_table);
     $panel->setNoBackground();
 
     return $panel;
   }
 
   private function renderHeadsupActionList(
     PhabricatorRepositoryCommit $commit,
     PhabricatorRepository $repository) {
 
     $request = $this->getRequest();
     $user = $request->getUser();
 
     $actions = id(new PhabricatorActionListView())
       ->setUser($user)
       ->setObject($commit)
       ->setObjectURI($request->getRequestURI());
 
     $can_edit = PhabricatorPolicyFilter::hasCapability(
       $user,
       $commit,
       PhabricatorPolicyCapability::CAN_EDIT);
 
     $uri = '/diffusion/'.$repository->getCallsign().'/commit/'.
            $commit->getCommitIdentifier().'/edit/';
 
     $action = id(new PhabricatorActionView())
       ->setName(pht('Edit Commit'))
       ->setHref($uri)
       ->setIcon('fa-pencil')
       ->setDisabled(!$can_edit)
       ->setWorkflow(!$can_edit);
     $actions->addAction($action);
 
     require_celerity_resource('phabricator-object-selector-css');
     require_celerity_resource('javelin-behavior-phabricator-object-selector');
 
     $maniphest = 'PhabricatorManiphestApplication';
     if (PhabricatorApplication::isClassInstalled($maniphest)) {
       $action = id(new PhabricatorActionView())
         ->setName(pht('Edit Maniphest Tasks'))
         ->setIcon('fa-anchor')
         ->setHref('/search/attach/'.$commit->getPHID().'/TASK/edge/')
         ->setWorkflow(true)
         ->setDisabled(!$can_edit);
       $actions->addAction($action);
     }
 
     $action = id(new PhabricatorActionView())
       ->setName(pht('Download Raw Diff'))
       ->setHref($request->getRequestURI()->alter('diff', true))
       ->setIcon('fa-download');
     $actions->addAction($action);
 
     return $actions;
   }
 
   private function buildRefs(DiffusionRequest $request) {
     // this is git-only, so save a conduit round trip and just get out of
     // here if the repository isn't git
     $type_git = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
     $repository = $request->getRepository();
     if ($repository->getVersionControlSystem() != $type_git) {
       return null;
     }
 
     $results = $this->callConduitWithDiffusionRequest(
       'diffusion.refsquery',
       array('commit' => $request->getCommit()));
     $ref_links = array();
     foreach ($results as $ref_data) {
       $ref_links[] = phutil_tag('a',
         array('href' => $ref_data['href']),
         $ref_data['ref']);
     }
     return phutil_implode_html(', ', $ref_links);
   }
 
   private function buildRawDiffResponse(DiffusionRequest $drequest) {
     $raw_diff = $this->callConduitWithDiffusionRequest(
       'diffusion.rawdiffquery',
       array(
         'commit' => $drequest->getCommit(),
         'path' => $drequest->getPath(),
       ));
 
     $file = PhabricatorFile::buildFromFileDataOrHash(
       $raw_diff,
       array(
         'name' => $drequest->getCommit().'.diff',
         'ttl' => (60 * 60 * 24),
         'viewPolicy' => PhabricatorPolicies::POLICY_NOONE,
       ));
 
     $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
       $file->attachToObject($drequest->getRepository()->getPHID());
     unset($unguarded);
 
     return $file->getRedirectResponse();
   }
 
   private function renderAuditStatusView(array $audit_requests) {
     assert_instances_of($audit_requests, 'PhabricatorRepositoryAuditRequest');
 
     $phids = mpull($audit_requests, 'getAuditorPHID');
     $this->loadHandles($phids);
 
     $authority_map = array_fill_keys($this->auditAuthorityPHIDs, true);
 
     $view = new PHUIStatusListView();
     foreach ($audit_requests as $request) {
       $code = $request->getAuditStatus();
       $item = new PHUIStatusItemView();
       $item->setIcon(
         PhabricatorAuditStatusConstants::getStatusIcon($code),
         PhabricatorAuditStatusConstants::getStatusColor($code),
         PhabricatorAuditStatusConstants::getStatusName($code));
 
       $note = array();
       foreach ($request->getAuditReasons() as $reason) {
         $note[] = phutil_tag('div', array(), $reason);
       }
       $item->setNote($note);
 
       $auditor_phid = $request->getAuditorPHID();
       $target = $this->getHandle($auditor_phid)->renderLink();
       $item->setTarget($target);
 
       if (isset($authority_map[$auditor_phid])) {
         $item->setHighlighted(true);
       }
 
       $view->addItem($item);
     }
 
     return $view;
   }
 
   private function linkBugtraq($corpus) {
     $url = PhabricatorEnv::getEnvConfig('bugtraq.url');
     if (!strlen($url)) {
       return $corpus;
     }
 
     $regexes = PhabricatorEnv::getEnvConfig('bugtraq.logregex');
     if (!$regexes) {
       return $corpus;
     }
 
     $parser = id(new PhutilBugtraqParser())
       ->setBugtraqPattern("[[ {$url} | %BUGID% ]]")
       ->setBugtraqCaptureExpression(array_shift($regexes));
 
     $select = array_shift($regexes);
     if ($select) {
       $parser->setBugtraqSelectExpression($select);
     }
 
     return $parser->processCorpus($corpus);
   }
 
 }
diff --git a/src/applications/diffusion/controller/DiffusionDiffController.php b/src/applications/diffusion/controller/DiffusionDiffController.php
index 92b7b64cd4..81460ea67a 100644
--- a/src/applications/diffusion/controller/DiffusionDiffController.php
+++ b/src/applications/diffusion/controller/DiffusionDiffController.php
@@ -1,127 +1,129 @@
 <?php
 
 final class DiffusionDiffController extends DiffusionController {
 
   public function shouldAllowPublic() {
     return true;
   }
 
   public function willProcessRequest(array $data) {
     $data = $data + array(
       'dblob' => $this->getRequest()->getStr('ref'),
     );
     $drequest = DiffusionRequest::newFromAphrontRequestDictionary(
       $data,
       $this->getRequest());
 
     $this->diffusionRequest = $drequest;
   }
 
   public function processRequest() {
     $drequest = $this->getDiffusionRequest();
     $request = $this->getRequest();
     $user = $request->getUser();
 
     if (!$request->isAjax()) {
 
       // This request came out of the dropdown menu, either "View Standalone"
       // or "View Raw File".
 
       $view = $request->getStr('view');
       if ($view == 'r') {
         $uri = $drequest->generateURI(
           array(
             'action' => 'browse',
             'params' => array(
               'view' => 'raw',
             ),
           ));
       } else {
         $uri = $drequest->generateURI(
           array(
             'action'  => 'change',
           ));
       }
 
       return id(new AphrontRedirectResponse())->setURI($uri);
     }
 
     $data = $this->callConduitWithDiffusionRequest(
       'diffusion.diffquery',
       array(
         'commit' => $drequest->getCommit(),
         'path' => $drequest->getPath(),
       ));
     $drequest->updateSymbolicCommit($data['effectiveCommit']);
     $raw_changes = ArcanistDiffChange::newFromConduit($data['changes']);
-    $diff = DifferentialDiff::newFromRawChanges($raw_changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      $user,
+      $raw_changes);
     $changesets = $diff->getChangesets();
     $changeset = reset($changesets);
 
     if (!$changeset) {
       return new Aphront404Response();
     }
 
     $parser = new DifferentialChangesetParser();
     $parser->setUser($user);
     $parser->setChangeset($changeset);
     $parser->setRenderingReference($drequest->generateURI(
       array(
         'action' => 'rendering-ref',
       )));
 
     $parser->setCharacterEncoding($request->getStr('encoding'));
     $parser->setHighlightAs($request->getStr('highlight'));
 
     $coverage = $drequest->loadCoverage();
     if ($coverage) {
       $parser->setCoverage($coverage);
     }
 
     $pquery = new DiffusionPathIDQuery(array($changeset->getFilename()));
     $ids = $pquery->loadPathIDs();
     $path_id = $ids[$changeset->getFilename()];
 
     $parser->setLeftSideCommentMapping($path_id, false);
     $parser->setRightSideCommentMapping($path_id, true);
 
     $parser->setWhitespaceMode(
       DifferentialChangesetParser::WHITESPACE_SHOW_ALL);
 
     $inlines = PhabricatorAuditInlineComment::loadDraftAndPublishedComments(
       $user,
       $drequest->loadCommit()->getPHID(),
       $path_id);
 
     if ($inlines) {
       foreach ($inlines as $inline) {
         $parser->parseInlineComment($inline);
       }
 
       $phids = mpull($inlines, 'getAuthorPHID');
       $handles = $this->loadViewerHandles($phids);
       $parser->setHandles($handles);
     }
 
     $engine = new PhabricatorMarkupEngine();
     $engine->setViewer($user);
 
     foreach ($inlines as $inline) {
       $engine->addObject(
         $inline,
         PhabricatorInlineCommentInterface::MARKUP_FIELD_BODY);
     }
 
     $engine->process();
 
     $parser->setMarkupEngine($engine);
 
     $spec = $request->getStr('range');
     list($range_s, $range_e, $mask) =
       DifferentialChangesetParser::parseRangeSpecification($spec);
     $output = $parser->render($range_s, $range_e, $mask);
 
     return id(new PhabricatorChangesetResponse())
       ->setRenderedChangeset($output);
   }
 }
diff --git a/src/applications/diffusion/data/DiffusionPathChange.php b/src/applications/diffusion/data/DiffusionPathChange.php
index 188669126e..e4f6fa182a 100644
--- a/src/applications/diffusion/data/DiffusionPathChange.php
+++ b/src/applications/diffusion/data/DiffusionPathChange.php
@@ -1,199 +1,201 @@
 <?php
 
 final class DiffusionPathChange {
 
   private $path;
   private $commitIdentifier;
   private $commit;
   private $commitData;
 
   private $changeType;
   private $fileType;
   private $targetPath;
   private $targetCommitIdentifier;
   private $awayPaths = array();
 
   final public function setPath($path) {
     $this->path = $path;
     return $this;
   }
 
   final public function getPath() {
     return $this->path;
   }
 
   public function setChangeType($change_type) {
     $this->changeType = $change_type;
     return $this;
   }
 
   public function getChangeType() {
     return $this->changeType;
   }
 
   public function setFileType($file_type) {
     $this->fileType = $file_type;
     return $this;
   }
 
   public function getFileType() {
     return $this->fileType;
   }
 
   public function setTargetPath($target_path) {
     $this->targetPath = $target_path;
     return $this;
   }
 
   public function getTargetPath() {
     return $this->targetPath;
   }
 
   public function setAwayPaths(array $away_paths) {
     $this->awayPaths = $away_paths;
     return $this;
   }
 
   public function getAwayPaths() {
     return $this->awayPaths;
   }
 
   final public function setCommitIdentifier($commit) {
     $this->commitIdentifier = $commit;
     return $this;
   }
 
   final public function getCommitIdentifier() {
     return $this->commitIdentifier;
   }
 
   final public function setTargetCommitIdentifier($target_commit_identifier) {
     $this->targetCommitIdentifier = $target_commit_identifier;
     return $this;
   }
 
   final public function getTargetCommitIdentifier() {
     return $this->targetCommitIdentifier;
   }
 
   final public function setCommit($commit) {
     $this->commit = $commit;
     return $this;
   }
 
   final public function getCommit() {
     return $this->commit;
   }
 
   final public function setCommitData($commit_data) {
     $this->commitData = $commit_data;
     return $this;
   }
 
   final public function getCommitData() {
     return $this->commitData;
   }
 
 
   final public function getEpoch() {
     if ($this->getCommit()) {
       return $this->getCommit()->getEpoch();
     }
     return null;
   }
 
   final public function getAuthorName() {
     if ($this->getCommitData()) {
       return $this->getCommitData()->getAuthorName();
     }
     return null;
   }
 
   final public function getSummary() {
     if (!$this->getCommitData()) {
       return null;
     }
     $message = $this->getCommitData()->getCommitMessage();
     $first = idx(explode("\n", $message), 0);
     return substr($first, 0, 80);
   }
 
   final public static function convertToArcanistChanges(array $changes) {
     assert_instances_of($changes, 'DiffusionPathChange');
     $direct = array();
     $result = array();
     foreach ($changes as $path) {
       $change = new ArcanistDiffChange();
       $change->setCurrentPath($path->getPath());
       $direct[] = $path->getPath();
       $change->setType($path->getChangeType());
       $file_type = $path->getFileType();
       if ($file_type == DifferentialChangeType::FILE_NORMAL) {
         $file_type = DifferentialChangeType::FILE_TEXT;
       }
       $change->setFileType($file_type);
       $change->setOldPath($path->getTargetPath());
       foreach ($path->getAwayPaths() as $away_path) {
         $change->addAwayPath($away_path);
       }
       $result[$path->getPath()] = $change;
     }
 
     return array_select_keys($result, $direct);
   }
 
-  final public static function convertToDifferentialChangesets(array $changes) {
+  final public static function convertToDifferentialChangesets(
+    PhabricatorUser $user,
+    array $changes) {
     assert_instances_of($changes, 'DiffusionPathChange');
     $arcanist_changes = self::convertToArcanistChanges($changes);
-    $diff = DifferentialDiff::newFromRawChanges($arcanist_changes);
+    $diff = DifferentialDiff::newFromRawChanges($user, $arcanist_changes);
     return $diff->getChangesets();
   }
 
   public function toDictionary() {
     $commit = $this->getCommit();
     if ($commit) {
       $commit_dict = $commit->toDictionary();
     } else {
       $commit_dict = array();
     }
     $commit_data = $this->getCommitData();
     if ($commit_data) {
       $commit_data_dict = $commit_data->toDictionary();
     } else {
       $commit_data_dict = array();
     }
     return array(
       'path' => $this->getPath(),
       'commitIdentifier' => $this->getCommitIdentifier(),
       'commit' => $commit_dict,
       'commitData' => $commit_data_dict,
       'fileType' => $this->getFileType(),
       'changeType' => $this->getChangeType(),
       'targetPath' =>  $this->getTargetPath(),
       'targetCommitIdentifier' => $this->getTargetCommitIdentifier(),
       'awayPaths' => $this->getAwayPaths(),
     );
   }
 
   public static function newFromConduit(array $dicts) {
     $results = array();
     foreach ($dicts as $dict) {
       $commit = PhabricatorRepositoryCommit::newFromDictionary($dict['commit']);
       $commit_data =
         PhabricatorRepositoryCommitData::newFromDictionary(
           $dict['commitData']);
       $results[] = id(new DiffusionPathChange())
         ->setPath($dict['path'])
         ->setCommitIdentifier($dict['commitIdentifier'])
         ->setCommit($commit)
         ->setCommitData($commit_data)
         ->setFileType($dict['fileType'])
         ->setChangeType($dict['changeType'])
         ->setTargetPath($dict['targetPath'])
         ->setTargetCommitIdentifier($dict['targetCommitIdentifier'])
         ->setAwayPaths($dict['awayPaths']);
     }
     return $results;
   }
 
 }
diff --git a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
index 09a65f3c3d..9e7d5ccef9 100644
--- a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
+++ b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
@@ -1,1186 +1,1188 @@
 <?php
 
 /**
  * @task config   Configuring the Hook Engine
  * @task hook     Hook Execution
  * @task git      Git Hooks
  * @task hg       Mercurial Hooks
  * @task svn      Subversion Hooks
  * @task internal Internals
  */
 final class DiffusionCommitHookEngine extends Phobject {
 
   const ENV_USER = 'PHABRICATOR_USER';
   const ENV_REMOTE_ADDRESS = 'PHABRICATOR_REMOTE_ADDRESS';
   const ENV_REMOTE_PROTOCOL = 'PHABRICATOR_REMOTE_PROTOCOL';
 
   const EMPTY_HASH = '0000000000000000000000000000000000000000';
 
   private $viewer;
   private $repository;
   private $stdin;
   private $originalArgv;
   private $subversionTransaction;
   private $subversionRepository;
   private $remoteAddress;
   private $remoteProtocol;
   private $transactionKey;
   private $mercurialHook;
   private $mercurialCommits = array();
   private $gitCommits = array();
 
   private $heraldViewerProjects;
   private $rejectCode = PhabricatorRepositoryPushLog::REJECT_BROKEN;
   private $rejectDetails;
   private $emailPHIDs = array();
 
 
 /* -(  Config  )------------------------------------------------------------- */
 
 
   public function setRemoteProtocol($remote_protocol) {
     $this->remoteProtocol = $remote_protocol;
     return $this;
   }
 
   public function getRemoteProtocol() {
     return $this->remoteProtocol;
   }
 
   public function setRemoteAddress($remote_address) {
     $this->remoteAddress = $remote_address;
     return $this;
   }
 
   public function getRemoteAddress() {
     return $this->remoteAddress;
   }
 
   private function getRemoteAddressForLog() {
     // If whatever we have here isn't a valid IPv4 address, just store `null`.
     // Older versions of PHP return `-1` on failure instead of `false`.
     $remote_address = $this->getRemoteAddress();
     $remote_address = max(0, ip2long($remote_address));
     $remote_address = nonempty($remote_address, null);
     return $remote_address;
   }
 
   public function setSubversionTransactionInfo($transaction, $repository) {
     $this->subversionTransaction = $transaction;
     $this->subversionRepository = $repository;
     return $this;
   }
 
   public function setStdin($stdin) {
     $this->stdin = $stdin;
     return $this;
   }
 
   public function getStdin() {
     return $this->stdin;
   }
 
   public function setOriginalArgv(array $original_argv) {
     $this->originalArgv = $original_argv;
     return $this;
   }
 
   public function getOriginalArgv() {
     return $this->originalArgv;
   }
 
   public function setRepository(PhabricatorRepository $repository) {
     $this->repository = $repository;
     return $this;
   }
 
   public function getRepository() {
     return $this->repository;
   }
 
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   public function getViewer() {
     return $this->viewer;
   }
 
   public function setMercurialHook($mercurial_hook) {
     $this->mercurialHook = $mercurial_hook;
     return $this;
   }
 
   public function getMercurialHook() {
     return $this->mercurialHook;
   }
 
 
 /* -(  Hook Execution  )----------------------------------------------------- */
 
 
   public function execute() {
     $ref_updates = $this->findRefUpdates();
     $all_updates = $ref_updates;
 
     $caught = null;
     try {
 
       try {
         $this->rejectDangerousChanges($ref_updates);
       } catch (DiffusionCommitHookRejectException $ex) {
         // If we're rejecting dangerous changes, flag everything that we've
         // seen as rejected so it's clear that none of it was accepted.
         $this->rejectCode = PhabricatorRepositoryPushLog::REJECT_DANGEROUS;
         throw $ex;
       }
 
       $this->applyHeraldRefRules($ref_updates, $all_updates);
 
       $content_updates = $this->findContentUpdates($ref_updates);
       $all_updates = array_merge($all_updates, $content_updates);
 
       $this->applyHeraldContentRules($content_updates, $all_updates);
 
       // Run custom scripts in `hook.d/` directories.
       $this->applyCustomHooks($all_updates);
 
       // If we make it this far, we're accepting these changes. Mark all the
       // logs as accepted.
       $this->rejectCode = PhabricatorRepositoryPushLog::REJECT_ACCEPT;
     } catch (Exception $ex) {
       // We'll throw this again in a minute, but we want to save all the logs
       // first.
       $caught = $ex;
     }
 
     // Save all the logs no matter what the outcome was.
     $event = $this->newPushEvent();
 
     $event->setRejectCode($this->rejectCode);
     $event->setRejectDetails($this->rejectDetails);
 
     $event->openTransaction();
       $event->save();
       foreach ($all_updates as $update) {
         $update->setPushEventPHID($event->getPHID());
         $update->save();
       }
     $event->saveTransaction();
 
     if ($caught) {
       throw $caught;
     }
 
     if ($this->emailPHIDs) {
       // If Herald rules triggered email to users, queue a worker to send the
       // mail. We do this out-of-process so that we block pushes as briefly
       // as possible.
 
       // (We do need to pull some commit info here because the commit objects
       // may not exist yet when this worker runs, which could be immediately.)
 
       PhabricatorWorker::scheduleTask(
         'PhabricatorRepositoryPushMailWorker',
         array(
           'eventPHID' => $event->getPHID(),
           'emailPHIDs' => array_values($this->emailPHIDs),
           'info' => $this->loadCommitInfoForWorker($all_updates),
         ),
         PhabricatorWorker::PRIORITY_ALERTS);
     }
 
     return 0;
   }
 
   private function findRefUpdates() {
     $type = $this->getRepository()->getVersionControlSystem();
     switch ($type) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         return $this->findGitRefUpdates();
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         return $this->findMercurialRefUpdates();
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         return $this->findSubversionRefUpdates();
       default:
         throw new Exception(pht('Unsupported repository type "%s"!', $type));
     }
   }
 
   private function rejectDangerousChanges(array $ref_updates) {
     assert_instances_of($ref_updates, 'PhabricatorRepositoryPushLog');
 
     $repository = $this->getRepository();
     if ($repository->shouldAllowDangerousChanges()) {
       return;
     }
 
     $flag_dangerous = PhabricatorRepositoryPushLog::CHANGEFLAG_DANGEROUS;
 
     foreach ($ref_updates as $ref_update) {
       if (!$ref_update->hasChangeFlags($flag_dangerous)) {
         // This is not a dangerous change.
         continue;
       }
 
       // We either have a branch deletion or a non fast-forward branch update.
       // Format a message and reject the push.
 
       $message = pht(
         "DANGEROUS CHANGE: %s\n".
         "Dangerous change protection is enabled for this repository.\n".
         "Edit the repository configuration before making dangerous changes.",
         $ref_update->getDangerousChangeDescription());
 
       throw new DiffusionCommitHookRejectException($message);
     }
   }
 
   private function findContentUpdates(array $ref_updates) {
     assert_instances_of($ref_updates, 'PhabricatorRepositoryPushLog');
 
     $type = $this->getRepository()->getVersionControlSystem();
     switch ($type) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         return $this->findGitContentUpdates($ref_updates);
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         return $this->findMercurialContentUpdates($ref_updates);
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         return $this->findSubversionContentUpdates($ref_updates);
       default:
         throw new Exception(pht('Unsupported repository type "%s"!', $type));
     }
   }
 
 
 /* -(  Herald  )------------------------------------------------------------- */
 
   private function applyHeraldRefRules(
     array $ref_updates,
     array $all_updates) {
     $this->applyHeraldRules(
       $ref_updates,
       new HeraldPreCommitRefAdapter(),
       $all_updates);
   }
 
   private function applyHeraldContentRules(
     array $content_updates,
     array $all_updates) {
     $this->applyHeraldRules(
       $content_updates,
       new HeraldPreCommitContentAdapter(),
       $all_updates);
   }
 
   private function applyHeraldRules(
     array $updates,
     HeraldAdapter $adapter_template,
     array $all_updates) {
 
     if (!$updates) {
       return;
     }
 
     $adapter_template->setHookEngine($this);
 
     $engine = new HeraldEngine();
     $rules = null;
     $blocking_effect = null;
     $blocked_update = null;
     foreach ($updates as $update) {
       $adapter = id(clone $adapter_template)
         ->setPushLog($update);
 
       if ($rules === null) {
         $rules = $engine->loadRulesForAdapter($adapter);
       }
 
       $effects = $engine->applyRules($rules, $adapter);
       $engine->applyEffects($effects, $adapter, $rules);
       $xscript = $engine->getTranscript();
 
       // Store any PHIDs we want to send email to for later.
       foreach ($adapter->getEmailPHIDs() as $email_phid) {
         $this->emailPHIDs[$email_phid] = $email_phid;
       }
 
       if ($blocking_effect === null) {
         foreach ($effects as $effect) {
           if ($effect->getAction() == HeraldAdapter::ACTION_BLOCK) {
             $blocking_effect = $effect;
             $blocked_update = $update;
             break;
           }
         }
       }
     }
 
     if ($blocking_effect) {
       $this->rejectCode = PhabricatorRepositoryPushLog::REJECT_HERALD;
       $this->rejectDetails = $blocking_effect->getRulePHID();
 
       $message = $blocking_effect->getTarget();
       if (!strlen($message)) {
         $message = pht('(None.)');
       }
 
       $rules = mpull($rules, null, 'getID');
       $rule = idx($rules, $effect->getRuleID());
       if ($rule && strlen($rule->getName())) {
         $rule_name = $rule->getName();
       } else {
         $rule_name = pht('Unnamed Herald Rule');
       }
 
       $blocked_ref_name = coalesce(
         $blocked_update->getRefName(),
         $blocked_update->getRefNewShort());
       $blocked_name = $blocked_update->getRefType().'/'.$blocked_ref_name;
 
       throw new DiffusionCommitHookRejectException(
         pht(
           "This push was rejected by Herald push rule %s.\n".
           "Change: %s\n".
           "  Rule: %s\n".
           "Reason: %s",
           'H'.$blocking_effect->getRuleID(),
           $blocked_name,
           $rule_name,
           $message));
     }
   }
 
   public function loadViewerProjectPHIDsForHerald() {
     // This just caches the viewer's projects so we don't need to load them
     // over and over again when applying Herald rules.
     if ($this->heraldViewerProjects === null) {
       $this->heraldViewerProjects = id(new PhabricatorProjectQuery())
         ->setViewer($this->getViewer())
         ->withMemberPHIDs(array($this->getViewer()->getPHID()))
         ->execute();
     }
 
     return mpull($this->heraldViewerProjects, 'getPHID');
   }
 
 
 /* -(  Git  )---------------------------------------------------------------- */
 
 
   private function findGitRefUpdates() {
     $ref_updates = array();
 
     // First, parse stdin, which lists all the ref changes. The input looks
     // like this:
     //
     //   <old hash> <new hash> <ref>
 
     $stdin = $this->getStdin();
     $lines = phutil_split_lines($stdin, $retain_endings = false);
     foreach ($lines as $line) {
       $parts = explode(' ', $line, 3);
       if (count($parts) != 3) {
         throw new Exception(pht('Expected "old new ref", got "%s".', $line));
       }
 
       $ref_old = $parts[0];
       $ref_new = $parts[1];
       $ref_raw = $parts[2];
 
       if (preg_match('(^refs/heads/)', $ref_raw)) {
         $ref_type = PhabricatorRepositoryPushLog::REFTYPE_BRANCH;
         $ref_raw = substr($ref_raw, strlen('refs/heads/'));
       } else if (preg_match('(^refs/tags/)', $ref_raw)) {
         $ref_type = PhabricatorRepositoryPushLog::REFTYPE_TAG;
         $ref_raw = substr($ref_raw, strlen('refs/tags/'));
       } else {
         throw new Exception(
           pht(
             "Unable to identify the reftype of '%s'. Rejecting push.",
             $ref_raw));
       }
 
       $ref_update = $this->newPushLog()
         ->setRefType($ref_type)
         ->setRefName($ref_raw)
         ->setRefOld($ref_old)
         ->setRefNew($ref_new);
 
       $ref_updates[] = $ref_update;
     }
 
     $this->findGitMergeBases($ref_updates);
     $this->findGitChangeFlags($ref_updates);
 
     return $ref_updates;
   }
 
 
   private function findGitMergeBases(array $ref_updates) {
     assert_instances_of($ref_updates, 'PhabricatorRepositoryPushLog');
 
     $futures = array();
     foreach ($ref_updates as $key => $ref_update) {
       // If the old hash is "00000...", the ref is being created (either a new
       // branch, or a new tag). If the new hash is "00000...", the ref is being
       // deleted. If both are nonempty, the ref is being updated. For updates,
       // we'll figure out the `merge-base` of the old and new objects here. This
       // lets us reject non-FF changes cheaply; later, we'll figure out exactly
       // which commits are new.
       $ref_old = $ref_update->getRefOld();
       $ref_new = $ref_update->getRefNew();
 
       if (($ref_old === self::EMPTY_HASH) ||
           ($ref_new === self::EMPTY_HASH)) {
         continue;
       }
 
       $futures[$key] = $this->getRepository()->getLocalCommandFuture(
         'merge-base %s %s',
         $ref_old,
         $ref_new);
     }
 
     foreach (Futures($futures)->limit(8) as $key => $future) {
 
       // If 'old' and 'new' have no common ancestors (for example, a force push
       // which completely rewrites a ref), `git merge-base` will exit with
       // an error and no output. It would be nice to find a positive test
       // for this instead, but I couldn't immediately come up with one. See
       // T4224. Assume this means there are no ancestors.
 
       list($err, $stdout) = $future->resolve();
 
       if ($err) {
         $merge_base = null;
       } else {
         $merge_base = rtrim($stdout, "\n");
       }
 
       $ref_update = $ref_updates[$key];
       $ref_update->setMergeBase($merge_base);
     }
 
     return $ref_updates;
   }
 
 
   private function findGitChangeFlags(array $ref_updates) {
     assert_instances_of($ref_updates, 'PhabricatorRepositoryPushLog');
 
     foreach ($ref_updates as $key => $ref_update) {
       $ref_old = $ref_update->getRefOld();
       $ref_new = $ref_update->getRefNew();
       $ref_type = $ref_update->getRefType();
 
       $ref_flags = 0;
       $dangerous = null;
 
       if (($ref_old === self::EMPTY_HASH) && ($ref_new === self::EMPTY_HASH)) {
         // This happens if you try to delete a tag or branch which does not
         // exist by pushing directly to the ref. Git will warn about it but
         // allow it. Just call it a delete, without flagging it as dangerous.
         $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DELETE;
       } else if ($ref_old === self::EMPTY_HASH) {
         $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_ADD;
       } else if ($ref_new === self::EMPTY_HASH) {
         $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DELETE;
         if ($ref_type == PhabricatorRepositoryPushLog::REFTYPE_BRANCH) {
           $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DANGEROUS;
           $dangerous = pht(
             "The change you're attempting to push deletes the branch '%s'.",
             $ref_update->getRefName());
         }
       } else {
         $merge_base = $ref_update->getMergeBase();
         if ($merge_base == $ref_old) {
           // This is a fast-forward update to an existing branch.
           // These are safe.
           $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_APPEND;
         } else {
           $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_REWRITE;
 
           // For now, we don't consider deleting or moving tags to be a
           // "dangerous" update. It's way harder to get wrong and should be easy
           // to recover from once we have better logging. Only add the dangerous
           // flag if this ref is a branch.
 
           if ($ref_type == PhabricatorRepositoryPushLog::REFTYPE_BRANCH) {
             $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DANGEROUS;
 
             $dangerous = pht(
               "The change you're attempting to push updates the branch '%s' ".
               "from '%s' to '%s', but this is not a fast-forward. Pushes ".
               "which rewrite published branch history are dangerous.",
               $ref_update->getRefName(),
               $ref_update->getRefOldShort(),
               $ref_update->getRefNewShort());
           }
         }
       }
 
       $ref_update->setChangeFlags($ref_flags);
       if ($dangerous !== null) {
         $ref_update->attachDangerousChangeDescription($dangerous);
       }
     }
 
     return $ref_updates;
   }
 
 
   private function findGitContentUpdates(array $ref_updates) {
     $flag_delete = PhabricatorRepositoryPushLog::CHANGEFLAG_DELETE;
 
     $futures = array();
     foreach ($ref_updates as $key => $ref_update) {
       if ($ref_update->hasChangeFlags($flag_delete)) {
         // Deleting a branch or tag can never create any new commits.
         continue;
       }
 
       // NOTE: This piece of magic finds all new commits, by walking backward
       // from the new value to the value of *any* existing ref in the
       // repository. Particularly, this will cover the cases of a new branch, a
       // completely moved tag, etc.
       $futures[$key] = $this->getRepository()->getLocalCommandFuture(
         'log --format=%s %s --not --all',
         '%H',
         $ref_update->getRefNew());
     }
 
     $content_updates = array();
     foreach (Futures($futures)->limit(8) as $key => $future) {
       list($stdout) = $future->resolvex();
 
       if (!strlen(trim($stdout))) {
         // This change doesn't have any new commits. One common case of this
         // is creating a new tag which points at an existing commit.
         continue;
       }
 
       $commits = phutil_split_lines($stdout, $retain_newlines = false);
 
       // If we're looking at a branch, mark all of the new commits as on that
       // branch. It's only possible for these commits to be on updated branches,
       // since any other branch heads are necessarily behind them.
       $branch_name = null;
       $ref_update = $ref_updates[$key];
       $type_branch = PhabricatorRepositoryPushLog::REFTYPE_BRANCH;
       if ($ref_update->getRefType() == $type_branch) {
         $branch_name = $ref_update->getRefName();
       }
 
       foreach ($commits as $commit) {
         if ($branch_name) {
           $this->gitCommits[$commit][] = $branch_name;
         }
         $content_updates[$commit] = $this->newPushLog()
           ->setRefType(PhabricatorRepositoryPushLog::REFTYPE_COMMIT)
           ->setRefNew($commit)
           ->setChangeFlags(PhabricatorRepositoryPushLog::CHANGEFLAG_ADD);
       }
     }
 
     return $content_updates;
   }
 
 /* -(  Custom  )------------------------------------------------------------- */
 
   private function applyCustomHooks(array $updates) {
     $args = $this->getOriginalArgv();
     $stdin = $this->getStdin();
     $console = PhutilConsole::getConsole();
 
     $env = array(
       'PHABRICATOR_REPOSITORY' => $this->getRepository()->getCallsign(),
       self::ENV_USER => $this->getViewer()->getUsername(),
       self::ENV_REMOTE_PROTOCOL => $this->getRemoteProtocol(),
       self::ENV_REMOTE_ADDRESS => $this->getRemoteAddress(),
     );
 
     $directories = $this->getRepository()->getHookDirectories();
     foreach ($directories as $directory) {
       $hooks = $this->getExecutablesInDirectory($directory);
       sort($hooks);
       foreach ($hooks as $hook) {
         // NOTE: We're explicitly running the hooks in sequential order to
         // make this more predictable.
         $future = id(new ExecFuture('%s %Ls', $hook, $args))
           ->setEnv($env, $wipe_process_env = false)
           ->write($stdin);
 
         list($err, $stdout, $stderr) = $future->resolve();
         if (!$err) {
           // This hook ran OK, but echo its output in case there was something
           // informative.
           $console->writeOut('%s', $stdout);
           $console->writeErr('%s', $stderr);
           continue;
         }
 
         $this->rejectCode = PhabricatorRepositoryPushLog::REJECT_EXTERNAL;
         $this->rejectDetails = basename($hook);
 
         throw new DiffusionCommitHookRejectException(
           pht(
             "This push was rejected by custom hook script '%s':\n\n%s%s",
             basename($hook),
             $stdout,
             $stderr));
       }
     }
   }
 
   private function getExecutablesInDirectory($directory) {
     $executables = array();
 
     if (!Filesystem::pathExists($directory)) {
       return $executables;
     }
 
     foreach (Filesystem::listDirectory($directory) as $path) {
       $full_path = $directory.DIRECTORY_SEPARATOR.$path;
       if (!is_executable($full_path)) {
         // Don't include non-executable files.
         continue;
       }
 
       if (basename($full_path) == 'README') {
         // Don't include README, even if it is marked as executable. It almost
         // certainly got caught in the crossfire of a sweeping `chmod`, since
         // users do this with some frequency.
         continue;
       }
 
       $executables[] = $full_path;
     }
 
     return $executables;
   }
 
 
 /* -(  Mercurial  )---------------------------------------------------------- */
 
 
   private function findMercurialRefUpdates() {
     $hook = $this->getMercurialHook();
     switch ($hook) {
       case 'pretxnchangegroup':
         return $this->findMercurialChangegroupRefUpdates();
       case 'prepushkey':
         return $this->findMercurialPushKeyRefUpdates();
       default:
         throw new Exception(pht('Unrecognized hook "%s"!', $hook));
     }
   }
 
   private function findMercurialChangegroupRefUpdates() {
     $hg_node = getenv('HG_NODE');
     if (!$hg_node) {
       throw new Exception(pht('Expected HG_NODE in environment!'));
     }
 
     // NOTE: We need to make sure this is passed to subprocesses, or they won't
     // be able to see new commits. Mercurial uses this as a marker to determine
     // whether the pending changes are visible or not.
     $_ENV['HG_PENDING'] = getenv('HG_PENDING');
     $repository = $this->getRepository();
 
     $futures = array();
 
     foreach (array('old', 'new') as $key) {
       $futures[$key] = $repository->getLocalCommandFuture(
         'heads --template %s',
         '{node}\1{branch}\2');
     }
     // Wipe HG_PENDING out of the old environment so we see the pre-commit
     // state of the repository.
     $futures['old']->updateEnv('HG_PENDING', null);
 
     $futures['commits'] = $repository->getLocalCommandFuture(
       'log --rev %s --template %s',
       hgsprintf('%s:%s', $hg_node, 'tip'),
       '{node}\1{branch}\2');
 
     // Resolve all of the futures now. We don't need the 'commits' future yet,
     // but it simplifies the logic to just get it out of the way.
     foreach (Futures($futures) as $future) {
       $future->resolve();
     }
 
     list($commit_raw) = $futures['commits']->resolvex();
     $commit_map = $this->parseMercurialCommits($commit_raw);
     $this->mercurialCommits = $commit_map;
 
     // NOTE: `hg heads` exits with an error code and no output if the repository
     // has no heads. Most commonly this happens on a new repository. We know
     // we can run `hg` successfully since the `hg log` above didn't error, so
     // just ignore the error code.
 
     list($err, $old_raw) = $futures['old']->resolve();
     $old_refs = $this->parseMercurialHeads($old_raw);
 
     list($err, $new_raw) = $futures['new']->resolve();
     $new_refs = $this->parseMercurialHeads($new_raw);
 
     $all_refs = array_keys($old_refs + $new_refs);
 
     $ref_updates = array();
     foreach ($all_refs as $ref) {
       $old_heads = idx($old_refs, $ref, array());
       $new_heads = idx($new_refs, $ref, array());
 
       sort($old_heads);
       sort($new_heads);
 
       if (!$old_heads && !$new_heads) {
         // This should never be possible, as it makes no sense. Explode.
         throw new Exception(
           pht(
             'Mercurial repository has no new or old heads for branch "%s" '.
             'after push. This makes no sense; rejecting change.',
             $ref));
       }
 
       if ($old_heads === $new_heads) {
         // No changes to this branch, so skip it.
         continue;
       }
 
       $stray_heads = array();
 
       if ($old_heads && !$new_heads) {
         // This is a branch deletion with "--close-branch".
         $head_map = array();
         foreach ($old_heads as $old_head) {
           $head_map[$old_head] = array(self::EMPTY_HASH);
         }
       } else if (count($old_heads) > 1) {
         // HORRIBLE: In Mercurial, branches can have multiple heads. If the
         // old branch had multiple heads, we need to figure out which new
         // heads descend from which old heads, so we can tell whether you're
         // actively creating new heads (dangerous) or just working in a
         // repository that's already full of garbage (strongly discouraged but
         // not as inherently dangerous). These cases should be very uncommon.
 
         // NOTE: We're only looking for heads on the same branch. The old
         // tip of the branch may be the branchpoint for other branches, but that
         // is OK.
 
         $dfutures = array();
         foreach ($old_heads as $old_head) {
           $dfutures[$old_head] = $repository->getLocalCommandFuture(
             'log --branch %s --rev %s --template %s',
             $ref,
             hgsprintf('(descendants(%s) and head())', $old_head),
             '{node}\1');
         }
 
         $head_map = array();
         foreach (Futures($dfutures) as $future_head => $dfuture) {
           list($stdout) = $dfuture->resolvex();
           $descendant_heads = array_filter(explode("\1", $stdout));
           if ($descendant_heads) {
             // This old head has at least one descendant in the push.
             $head_map[$future_head] = $descendant_heads;
           } else {
             // This old head has no descendants, so it is being deleted.
             $head_map[$future_head] = array(self::EMPTY_HASH);
           }
         }
 
         // Now, find all the new stray heads this push creates, if any. These
         // are new heads which do not descend from the old heads.
         $seen = array_fuse(array_mergev($head_map));
         foreach ($new_heads as $new_head) {
           if ($new_head === self::EMPTY_HASH) {
             // If a branch head is being deleted, don't insert it as an add.
             continue;
           }
           if (empty($seen[$new_head])) {
             $head_map[self::EMPTY_HASH][] = $new_head;
           }
         }
       } else if ($old_heads) {
         $head_map[head($old_heads)] = $new_heads;
       } else {
         $head_map[self::EMPTY_HASH] = $new_heads;
       }
 
       foreach ($head_map as $old_head => $child_heads) {
         foreach ($child_heads as $new_head) {
           if ($new_head === $old_head) {
             continue;
           }
 
           $ref_flags = 0;
           $dangerous = null;
           if ($old_head == self::EMPTY_HASH) {
             $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_ADD;
           } else {
             $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_APPEND;
           }
 
 
           $deletes_existing_head = ($new_head == self::EMPTY_HASH);
           $splits_existing_head = (count($child_heads) > 1);
           $creates_duplicate_head = ($old_head == self::EMPTY_HASH) &&
                                     (count($head_map) > 1);
 
           if ($splits_existing_head || $creates_duplicate_head) {
             $readable_child_heads = array();
             foreach ($child_heads as $child_head) {
               $readable_child_heads[] = substr($child_head, 0, 12);
             }
 
             $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DANGEROUS;
 
             if ($splits_existing_head) {
               // We're splitting an existing head into two or more heads.
               // This is dangerous, and a super bad idea. Note that we're only
               // raising this if you're actively splitting a branch head. If a
               // head split in the past, we don't consider appends to it
               // to be dangerous.
               $dangerous = pht(
                 "The change you're attempting to push splits the head of ".
                 "branch '%s' into multiple heads: %s. This is inadvisable ".
                 "and dangerous.",
                 $ref,
                 implode(', ', $readable_child_heads));
             } else {
               // We're adding a second (or more) head to a branch. The new
               // head is not a descendant of any old head.
               $dangerous = pht(
                 "The change you're attempting to push creates new, divergent ".
                 "heads for the branch '%s': %s. This is inadvisable and ".
                 "dangerous.",
                 $ref,
                 implode(', ', $readable_child_heads));
             }
           }
 
           if ($deletes_existing_head) {
             // TODO: Somewhere in here we should be setting CHANGEFLAG_REWRITE
             // if we are also creating at least one other head to replace
             // this one.
 
             // NOTE: In Git, this is a dangerous change, but it is not dangerous
             // in Mercurial. Mercurial branches are version controlled, and
             // Mercurial does not prompt you for any special flags when pushing
             // a `--close-branch` commit by default.
 
             $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DELETE;
           }
 
           $ref_update = $this->newPushLog()
             ->setRefType(PhabricatorRepositoryPushLog::REFTYPE_BRANCH)
             ->setRefName($ref)
             ->setRefOld($old_head)
             ->setRefNew($new_head)
             ->setChangeFlags($ref_flags);
 
           if ($dangerous !== null) {
             $ref_update->attachDangerousChangeDescription($dangerous);
           }
 
           $ref_updates[] = $ref_update;
         }
       }
     }
 
     return $ref_updates;
   }
 
   private function findMercurialPushKeyRefUpdates() {
     $key_namespace = getenv('HG_NAMESPACE');
 
     if ($key_namespace === 'phases') {
       // Mercurial changes commit phases as part of normal push operations. We
       // just ignore these, as they don't seem to represent anything
       // interesting.
       return array();
     }
 
     $key_name = getenv('HG_KEY');
 
     $key_old = getenv('HG_OLD');
     if (!strlen($key_old)) {
       $key_old = null;
     }
 
     $key_new = getenv('HG_NEW');
     if (!strlen($key_new)) {
       $key_new = null;
     }
 
     if ($key_namespace !== 'bookmarks') {
       throw new Exception(
         pht(
           "Unknown Mercurial key namespace '%s', with key '%s' (%s -> %s). ".
           "Rejecting push.",
           $key_namespace,
           $key_name,
           coalesce($key_old, pht('null')),
           coalesce($key_new, pht('null'))));
     }
 
     if ($key_old === $key_new) {
       // We get a callback when the bookmark doesn't change. Just ignore this,
       // as it's a no-op.
       return array();
     }
 
     $ref_flags = 0;
     $merge_base = null;
     if ($key_old === null) {
       $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_ADD;
     } else if ($key_new === null) {
       $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_DELETE;
     } else {
       list($merge_base_raw) = $this->getRepository()->execxLocalCommand(
         'log --template %s --rev %s',
         '{node}',
         hgsprintf('ancestor(%s, %s)', $key_old, $key_new));
 
       if (strlen(trim($merge_base_raw))) {
         $merge_base = trim($merge_base_raw);
       }
 
       if ($merge_base && ($merge_base === $key_old)) {
         $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_APPEND;
       } else {
         $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_REWRITE;
       }
     }
 
     $ref_update = $this->newPushLog()
       ->setRefType(PhabricatorRepositoryPushLog::REFTYPE_BOOKMARK)
       ->setRefName($key_name)
       ->setRefOld(coalesce($key_old, self::EMPTY_HASH))
       ->setRefNew(coalesce($key_new, self::EMPTY_HASH))
       ->setChangeFlags($ref_flags);
 
     return array($ref_update);
   }
 
   private function findMercurialContentUpdates(array $ref_updates) {
     $content_updates = array();
 
     foreach ($this->mercurialCommits as $commit => $branches) {
       $content_updates[$commit] = $this->newPushLog()
         ->setRefType(PhabricatorRepositoryPushLog::REFTYPE_COMMIT)
         ->setRefNew($commit)
         ->setChangeFlags(PhabricatorRepositoryPushLog::CHANGEFLAG_ADD);
     }
 
     return $content_updates;
   }
 
   private function parseMercurialCommits($raw) {
     $commits_lines = explode("\2", $raw);
     $commits_lines = array_filter($commits_lines);
     $commit_map = array();
     foreach ($commits_lines as $commit_line) {
       list($node, $branch) = explode("\1", $commit_line);
       $commit_map[$node] = array($branch);
     }
 
     return $commit_map;
   }
 
   private function parseMercurialHeads($raw) {
     $heads_map = $this->parseMercurialCommits($raw);
 
     $heads = array();
     foreach ($heads_map as $commit => $branches) {
       foreach ($branches as $branch) {
         $heads[$branch][] = $commit;
       }
     }
 
     return $heads;
   }
 
 
 /* -(  Subversion  )--------------------------------------------------------- */
 
 
   private function findSubversionRefUpdates() {
     // Subversion doesn't have any kind of mutable ref metadata.
     return array();
   }
 
   private function findSubversionContentUpdates(array $ref_updates) {
     list($youngest) = execx(
       'svnlook youngest %s',
       $this->subversionRepository);
     $ref_new = (int)$youngest + 1;
 
     $ref_flags = 0;
     $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_ADD;
     $ref_flags |= PhabricatorRepositoryPushLog::CHANGEFLAG_APPEND;
 
     $ref_content = $this->newPushLog()
       ->setRefType(PhabricatorRepositoryPushLog::REFTYPE_COMMIT)
       ->setRefNew($ref_new)
       ->setChangeFlags($ref_flags);
 
     return array($ref_content);
   }
 
 
 /* -(  Internals  )---------------------------------------------------------- */
 
 
   private function newPushLog() {
     // NOTE: We generate PHIDs up front so the Herald transcripts can pick them
     // up.
     $phid = id(new PhabricatorRepositoryPushLog())->generatePHID();
 
     return PhabricatorRepositoryPushLog::initializeNewLog($this->getViewer())
       ->setPHID($phid)
       ->setRepositoryPHID($this->getRepository()->getPHID())
       ->attachRepository($this->getRepository())
       ->setEpoch(time());
   }
 
   private function newPushEvent() {
     $viewer = $this->getViewer();
     return PhabricatorRepositoryPushEvent::initializeNewEvent($viewer)
       ->setRepositoryPHID($this->getRepository()->getPHID())
       ->setRemoteAddress($this->getRemoteAddressForLog())
       ->setRemoteProtocol($this->getRemoteProtocol())
       ->setEpoch(time());
   }
 
   public function loadChangesetsForCommit($identifier) {
     $byte_limit = HeraldCommitAdapter::getEnormousByteLimit();
     $time_limit = HeraldCommitAdapter::getEnormousTimeLimit();
 
     $vcs = $this->getRepository()->getVersionControlSystem();
     switch ($vcs) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         // For git and hg, we can use normal commands.
         $drequest = DiffusionRequest::newFromDictionary(
           array(
             'repository' => $this->getRepository(),
             'user' => $this->getViewer(),
             'commit' => $identifier,
           ));
 
         $raw_diff = DiffusionRawDiffQuery::newFromDiffusionRequest($drequest)
           ->setTimeout($time_limit)
           ->setByteLimit($byte_limit)
           ->setLinesOfContext(0)
           ->loadRawDiff();
         break;
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         // TODO: This diff has 3 lines of context, which produces slightly
         // incorrect "added file content" and "removed file content" results.
         // This may also choke on binaries, but "svnlook diff" does not support
         // the "--diff-cmd" flag.
 
         // For subversion, we need to use `svnlook`.
         $future = new ExecFuture(
           'svnlook diff -t %s %s',
           $this->subversionTransaction,
           $this->subversionRepository);
 
         $future->setTimeout($time_limit);
         $future->setStdoutSizeLimit($byte_limit);
         $future->setStderrSizeLimit($byte_limit);
 
         list($raw_diff) = $future->resolvex();
         break;
       default:
         throw new Exception(pht("Unknown VCS '%s!'", $vcs));
     }
 
     if (strlen($raw_diff) >= $byte_limit) {
       throw new Exception(
         pht(
           'The raw text of this change is enormous (larger than %d '.
           'bytes). Herald can not process it.',
           $byte_limit));
     }
 
     if (!strlen($raw_diff)) {
       // If the commit is actually empty, just return no changesets.
       return array();
     }
 
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($raw_diff);
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      $this->getViewer(),
+      $changes);
     return $diff->getChangesets();
   }
 
   public function loadCommitRefForCommit($identifier) {
     $repository = $this->getRepository();
     $vcs = $repository->getVersionControlSystem();
     switch ($vcs) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         return id(new DiffusionLowLevelCommitQuery())
           ->setRepository($repository)
           ->withIdentifier($identifier)
           ->execute();
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         // For subversion, we need to use `svnlook`.
         list($message) = execx(
           'svnlook log -t %s %s',
           $this->subversionTransaction,
           $this->subversionRepository);
 
         return id(new DiffusionCommitRef())
           ->setMessage($message);
         break;
       default:
         throw new Exception(pht("Unknown VCS '%s!'", $vcs));
     }
   }
 
   public function loadBranches($identifier) {
     $repository = $this->getRepository();
     $vcs = $repository->getVersionControlSystem();
     switch ($vcs) {
       case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
         return idx($this->gitCommits, $identifier, array());
       case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
         // NOTE: This will be "the branch the commit was made to", not
         // "a list of all branch heads which descend from the commit".
         // This is consistent with Mercurial, but possibly confusing.
         return idx($this->mercurialCommits, $identifier, array());
       case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         // Subversion doesn't have branches.
         return array();
     }
   }
 
   private function loadCommitInfoForWorker(array $all_updates) {
     $type_commit = PhabricatorRepositoryPushLog::REFTYPE_COMMIT;
 
     $map = array();
     foreach ($all_updates as $update) {
       if ($update->getRefType() != $type_commit) {
         continue;
       }
       $map[$update->getRefNew()] = array();
     }
 
     foreach ($map as $identifier => $info) {
       $ref = $this->loadCommitRefForCommit($identifier);
       $map[$identifier] += array(
         'summary'  => $ref->getSummary(),
         'branches' => $this->loadBranches($identifier),
       );
     }
 
     return $map;
   }
 
 }
diff --git a/src/applications/herald/adapter/HeraldCommitAdapter.php b/src/applications/herald/adapter/HeraldCommitAdapter.php
index e52ad18fa6..35e93f5916 100644
--- a/src/applications/herald/adapter/HeraldCommitAdapter.php
+++ b/src/applications/herald/adapter/HeraldCommitAdapter.php
@@ -1,562 +1,564 @@
 <?php
 
 final class HeraldCommitAdapter extends HeraldAdapter {
 
   const FIELD_NEED_AUDIT_FOR_PACKAGE      = 'need-audit-for-package';
   const FIELD_REPOSITORY_AUTOCLOSE_BRANCH = 'repository-autoclose-branch';
 
   protected $diff;
   protected $revision;
 
   protected $repository;
   protected $commit;
   protected $commitData;
   private $commitDiff;
 
   protected $emailPHIDs = array();
   protected $addCCPHIDs = array();
   protected $auditMap = array();
   protected $buildPlans = array();
 
   protected $affectedPaths;
   protected $affectedRevision;
   protected $affectedPackages;
   protected $auditNeededPackages;
 
   public function getAdapterApplicationClass() {
     return 'PhabricatorDiffusionApplication';
   }
 
   public function getObject() {
     return $this->commit;
   }
 
   public function getAdapterContentType() {
     return 'commit';
   }
 
   public function getAdapterContentName() {
     return pht('Commits');
   }
 
   public function getAdapterContentDescription() {
     return pht(
       "React to new commits appearing in tracked repositories.\n".
       "Commit rules can send email, flag commits, trigger audits, ".
       "and run build plans.");
   }
 
   public function supportsRuleType($rule_type) {
     switch ($rule_type) {
       case HeraldRuleTypeConfig::RULE_TYPE_GLOBAL:
       case HeraldRuleTypeConfig::RULE_TYPE_PERSONAL:
       case HeraldRuleTypeConfig::RULE_TYPE_OBJECT:
         return true;
       default:
         return false;
     }
   }
 
   public function canTriggerOnObject($object) {
     if ($object instanceof PhabricatorRepository) {
       return true;
     }
     if ($object instanceof PhabricatorProject) {
       return true;
     }
     return false;
   }
 
   public function getTriggerObjectPHIDs() {
     return array_merge(
       array(
         $this->repository->getPHID(),
         $this->getPHID(),
       ),
       $this->repository->getProjectPHIDs());
   }
 
   public function explainValidTriggerObjects() {
     return pht('This rule can trigger for **repositories** and **projects**.');
   }
 
   public function getFieldNameMap() {
     return array(
       self::FIELD_NEED_AUDIT_FOR_PACKAGE =>
         pht('Affected packages that need audit'),
       self::FIELD_REPOSITORY_AUTOCLOSE_BRANCH
         => pht('Commit is on closing branch'),
     ) + parent::getFieldNameMap();
   }
 
   public function getFields() {
     return array_merge(
       array(
         self::FIELD_BODY,
         self::FIELD_AUTHOR,
         self::FIELD_COMMITTER,
         self::FIELD_REVIEWER,
         self::FIELD_REPOSITORY,
         self::FIELD_REPOSITORY_PROJECTS,
         self::FIELD_DIFF_FILE,
         self::FIELD_DIFF_CONTENT,
         self::FIELD_DIFF_ADDED_CONTENT,
         self::FIELD_DIFF_REMOVED_CONTENT,
         self::FIELD_DIFF_ENORMOUS,
         self::FIELD_AFFECTED_PACKAGE,
         self::FIELD_AFFECTED_PACKAGE_OWNER,
         self::FIELD_NEED_AUDIT_FOR_PACKAGE,
         self::FIELD_DIFFERENTIAL_REVISION,
         self::FIELD_DIFFERENTIAL_ACCEPTED,
         self::FIELD_DIFFERENTIAL_REVIEWERS,
         self::FIELD_DIFFERENTIAL_CCS,
         self::FIELD_BRANCHES,
         self::FIELD_REPOSITORY_AUTOCLOSE_BRANCH,
       ),
       parent::getFields());
   }
 
   public function getConditionsForField($field) {
     switch ($field) {
       case self::FIELD_NEED_AUDIT_FOR_PACKAGE:
         return array(
           self::CONDITION_INCLUDE_ANY,
           self::CONDITION_INCLUDE_NONE,
         );
       case self::FIELD_REPOSITORY_AUTOCLOSE_BRANCH:
         return array(
           self::CONDITION_UNCONDITIONALLY,
         );
     }
     return parent::getConditionsForField($field);
   }
 
   public function getActions($rule_type) {
     switch ($rule_type) {
       case HeraldRuleTypeConfig::RULE_TYPE_GLOBAL:
       case HeraldRuleTypeConfig::RULE_TYPE_OBJECT:
         return array_merge(
           array(
             self::ACTION_ADD_CC,
             self::ACTION_EMAIL,
             self::ACTION_AUDIT,
             self::ACTION_APPLY_BUILD_PLANS,
             self::ACTION_NOTHING,
           ),
           parent::getActions($rule_type));
       case HeraldRuleTypeConfig::RULE_TYPE_PERSONAL:
         return array_merge(
           array(
             self::ACTION_ADD_CC,
             self::ACTION_EMAIL,
             self::ACTION_FLAG,
             self::ACTION_AUDIT,
             self::ACTION_NOTHING,
           ),
           parent::getActions($rule_type));
     }
   }
 
   public function getValueTypeForFieldAndCondition($field, $condition) {
     switch ($field) {
       case self::FIELD_DIFFERENTIAL_CCS:
         return self::VALUE_EMAIL;
       case self::FIELD_NEED_AUDIT_FOR_PACKAGE:
         return self::VALUE_OWNERS_PACKAGE;
     }
 
     return parent::getValueTypeForFieldAndCondition($field, $condition);
   }
 
   public static function newLegacyAdapter(
     PhabricatorRepository $repository,
     PhabricatorRepositoryCommit $commit,
     PhabricatorRepositoryCommitData $commit_data) {
 
     $object = new HeraldCommitAdapter();
 
     $commit->attachRepository($repository);
 
     $object->repository = $repository;
     $object->commit = $commit;
     $object->commitData = $commit_data;
 
     return $object;
   }
 
   public function setCommit(PhabricatorRepositoryCommit $commit) {
     $viewer = PhabricatorUser::getOmnipotentUser();
 
     $repository = id(new PhabricatorRepositoryQuery())
       ->setViewer($viewer)
       ->withIDs(array($commit->getRepositoryID()))
       ->needProjectPHIDs(true)
       ->executeOne();
     if (!$repository) {
       throw new Exception(pht('Unable to load repository!'));
     }
 
     $data = id(new PhabricatorRepositoryCommitData())->loadOneWhere(
       'commitID = %d',
       $commit->getID());
     if (!$data) {
       throw new Exception(pht('Unable to load commit data!'));
     }
 
     $this->commit = clone $commit;
     $this->commit->attachRepository($repository);
     $this->commit->attachCommitData($data);
 
     $this->repository = $repository;
     $this->commitData = $data;
 
     return $this;
   }
 
   public function getPHID() {
     return $this->commit->getPHID();
   }
 
   public function getEmailPHIDs() {
     return array_keys($this->emailPHIDs);
   }
 
   public function getAddCCMap() {
     return $this->addCCPHIDs;
   }
 
   public function getAuditMap() {
     return $this->auditMap;
   }
 
   public function getBuildPlans() {
     return $this->buildPlans;
   }
 
   public function getHeraldName() {
     return
       'r'.
       $this->repository->getCallsign().
       $this->commit->getCommitIdentifier();
   }
 
   public function loadAffectedPaths() {
     if ($this->affectedPaths === null) {
       $result = PhabricatorOwnerPathQuery::loadAffectedPaths(
         $this->repository,
         $this->commit,
         PhabricatorUser::getOmnipotentUser());
       $this->affectedPaths = $result;
     }
     return $this->affectedPaths;
   }
 
   public function loadAffectedPackages() {
     if ($this->affectedPackages === null) {
       $packages = PhabricatorOwnersPackage::loadAffectedPackages(
         $this->repository,
         $this->loadAffectedPaths());
       $this->affectedPackages = $packages;
     }
     return $this->affectedPackages;
   }
 
   public function loadAuditNeededPackage() {
     if ($this->auditNeededPackages === null) {
       $status_arr = array(
         PhabricatorAuditStatusConstants::AUDIT_REQUIRED,
         PhabricatorAuditStatusConstants::CONCERNED,
       );
       $requests = id(new PhabricatorRepositoryAuditRequest())
           ->loadAllWhere(
         'commitPHID = %s AND auditStatus IN (%Ls)',
         $this->commit->getPHID(),
         $status_arr);
 
       $packages = mpull($requests, 'getAuditorPHID');
       $this->auditNeededPackages = $packages;
     }
     return $this->auditNeededPackages;
   }
 
   public function loadDifferentialRevision() {
     if ($this->affectedRevision === null) {
       $this->affectedRevision = false;
       $data = $this->commitData;
       $revision_id = $data->getCommitDetail('differential.revisionID');
       if ($revision_id) {
         // NOTE: The Herald rule owner might not actually have access to
         // the revision, and can control which revision a commit is
         // associated with by putting text in the commit message. However,
         // the rules they can write against revisions don't actually expose
         // anything interesting, so it seems reasonable to load unconditionally
         // here.
 
         $revision = id(new DifferentialRevisionQuery())
           ->withIDs(array($revision_id))
           ->setViewer(PhabricatorUser::getOmnipotentUser())
           ->needRelationships(true)
           ->needReviewerStatus(true)
           ->executeOne();
         if ($revision) {
           $this->affectedRevision = $revision;
         }
       }
     }
     return $this->affectedRevision;
   }
 
   public static function getEnormousByteLimit() {
     return 1024 * 1024 * 1024; // 1GB
   }
 
   public static function getEnormousTimeLimit() {
     return 60 * 15; // 15 Minutes
   }
 
   private function loadCommitDiff() {
     $drequest = DiffusionRequest::newFromDictionary(
       array(
         'user' => PhabricatorUser::getOmnipotentUser(),
         'repository' => $this->repository,
         'commit' => $this->commit->getCommitIdentifier(),
       ));
 
     $byte_limit = self::getEnormousByteLimit();
 
     $raw = DiffusionQuery::callConduitWithDiffusionRequest(
       PhabricatorUser::getOmnipotentUser(),
       $drequest,
       'diffusion.rawdiffquery',
       array(
         'commit' => $this->commit->getCommitIdentifier(),
         'timeout' => self::getEnormousTimeLimit(),
         'byteLimit' => $byte_limit,
         'linesOfContext' => 0,
       ));
 
     if (strlen($raw) >= $byte_limit) {
       throw new Exception(
         pht(
           'The raw text of this change is enormous (larger than %d bytes). '.
           'Herald can not process it.',
           $byte_limit));
     }
 
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($raw);
 
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $changes);
     return $diff;
   }
 
   private function getDiffContent($type) {
     if ($this->commitDiff === null) {
       try {
         $this->commitDiff = $this->loadCommitDiff();
       } catch (Exception $ex) {
         $this->commitDiff = $ex;
         phlog($ex);
       }
     }
 
     if ($this->commitDiff instanceof Exception) {
       $ex = $this->commitDiff;
       $ex_class = get_class($ex);
       $ex_message = pht('Failed to load changes: %s', $ex->getMessage());
 
       return array(
         '<'.$ex_class.'>' => $ex_message,
       );
     }
 
     $changes = $this->commitDiff->getChangesets();
 
     $result = array();
     foreach ($changes as $change) {
       $lines = array();
       foreach ($change->getHunks() as $hunk) {
         switch ($type) {
           case '-':
             $lines[] = $hunk->makeOldFile();
             break;
           case '+':
             $lines[] = $hunk->makeNewFile();
             break;
           case '*':
             $lines[] = $hunk->makeChanges();
             break;
           default:
             throw new Exception("Unknown content selection '{$type}'!");
         }
       }
       $result[$change->getFilename()] = implode("\n", $lines);
     }
 
     return $result;
   }
 
   public function getHeraldField($field) {
     $data = $this->commitData;
     switch ($field) {
       case self::FIELD_BODY:
         return $data->getCommitMessage();
       case self::FIELD_AUTHOR:
         return $data->getCommitDetail('authorPHID');
       case self::FIELD_COMMITTER:
         return $data->getCommitDetail('committerPHID');
       case self::FIELD_REVIEWER:
         return $data->getCommitDetail('reviewerPHID');
       case self::FIELD_DIFF_FILE:
         return $this->loadAffectedPaths();
       case self::FIELD_REPOSITORY:
         return $this->repository->getPHID();
       case self::FIELD_REPOSITORY_PROJECTS:
         return $this->repository->getProjectPHIDs();
       case self::FIELD_DIFF_CONTENT:
         return $this->getDiffContent('*');
       case self::FIELD_DIFF_ADDED_CONTENT:
         return $this->getDiffContent('+');
       case self::FIELD_DIFF_REMOVED_CONTENT:
         return $this->getDiffContent('-');
       case self::FIELD_DIFF_ENORMOUS:
         $this->getDiffContent('*');
         return ($this->commitDiff instanceof Exception);
       case self::FIELD_AFFECTED_PACKAGE:
         $packages = $this->loadAffectedPackages();
         return mpull($packages, 'getPHID');
       case self::FIELD_AFFECTED_PACKAGE_OWNER:
         $packages = $this->loadAffectedPackages();
         $owners = PhabricatorOwnersOwner::loadAllForPackages($packages);
         return mpull($owners, 'getUserPHID');
       case self::FIELD_NEED_AUDIT_FOR_PACKAGE:
         return $this->loadAuditNeededPackage();
       case self::FIELD_DIFFERENTIAL_REVISION:
         $revision = $this->loadDifferentialRevision();
         if (!$revision) {
           return null;
         }
         return $revision->getID();
       case self::FIELD_DIFFERENTIAL_ACCEPTED:
         $revision = $this->loadDifferentialRevision();
         if (!$revision) {
           return null;
         }
 
         $status = $data->getCommitDetail(
           'precommitRevisionStatus',
           $revision->getStatus());
         switch ($status) {
           case ArcanistDifferentialRevisionStatus::ACCEPTED:
           case ArcanistDifferentialRevisionStatus::CLOSED:
             return $revision->getPHID();
         }
 
         return null;
       case self::FIELD_DIFFERENTIAL_REVIEWERS:
         $revision = $this->loadDifferentialRevision();
         if (!$revision) {
           return array();
         }
         return $revision->getReviewers();
       case self::FIELD_DIFFERENTIAL_CCS:
         $revision = $this->loadDifferentialRevision();
         if (!$revision) {
           return array();
         }
         return $revision->getCCPHIDs();
       case self::FIELD_BRANCHES:
         $params = array(
           'callsign' => $this->repository->getCallsign(),
           'contains' => $this->commit->getCommitIdentifier(),
         );
 
         $result = id(new ConduitCall('diffusion.branchquery', $params))
           ->setUser(PhabricatorUser::getOmnipotentUser())
           ->execute();
 
         $refs = DiffusionRepositoryRef::loadAllFromDictionaries($result);
         return mpull($refs, 'getShortName');
       case self::FIELD_REPOSITORY_AUTOCLOSE_BRANCH:
         return $this->repository->shouldAutocloseCommit($this->commit);
     }
 
     return parent::getHeraldField($field);
   }
 
   public function applyHeraldEffects(array $effects) {
     assert_instances_of($effects, 'HeraldEffect');
 
     $result = array();
     foreach ($effects as $effect) {
       $action = $effect->getAction();
       switch ($action) {
         case self::ACTION_NOTHING:
           $result[] = new HeraldApplyTranscript(
             $effect,
             true,
             pht('Great success at doing nothing.'));
           break;
         case self::ACTION_EMAIL:
           foreach ($effect->getTarget() as $phid) {
             $this->emailPHIDs[$phid] = true;
           }
           $result[] = new HeraldApplyTranscript(
             $effect,
             true,
             pht('Added address to email targets.'));
           break;
         case self::ACTION_ADD_CC:
           foreach ($effect->getTarget() as $phid) {
             if (empty($this->addCCPHIDs[$phid])) {
               $this->addCCPHIDs[$phid] = array();
             }
             $this->addCCPHIDs[$phid][] = $effect->getRuleID();
           }
           $result[] = new HeraldApplyTranscript(
             $effect,
             true,
             pht('Added address to CC.'));
           break;
         case self::ACTION_AUDIT:
           foreach ($effect->getTarget() as $phid) {
             if (empty($this->auditMap[$phid])) {
               $this->auditMap[$phid] = array();
             }
             $this->auditMap[$phid][] = $effect->getRuleID();
           }
           $result[] = new HeraldApplyTranscript(
             $effect,
             true,
             pht('Triggered an audit.'));
           break;
         case self::ACTION_APPLY_BUILD_PLANS:
           foreach ($effect->getTarget() as $phid) {
             $this->buildPlans[] = $phid;
           }
           $result[] = new HeraldApplyTranscript(
             $effect,
             true,
             pht('Applied build plans.'));
           break;
         case self::ACTION_FLAG:
           $result[] = parent::applyFlagEffect(
             $effect,
             $this->commit->getPHID());
           break;
         default:
           $custom_result = parent::handleCustomHeraldEffect($effect);
           if ($custom_result === null) {
             throw new Exception(pht(
               "No rules to handle action '%s'.",
               $action));
           }
 
           $result[] = $custom_result;
           break;
       }
     }
     return $result;
   }
 
 }
diff --git a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
index 7c56251dea..f97fefc4c6 100644
--- a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
+++ b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
@@ -1,517 +1,517 @@
 <?php
 
 abstract class PhabricatorRepositoryCommitMessageParserWorker
   extends PhabricatorRepositoryCommitParserWorker {
 
   final protected function updateCommitData(DiffusionCommitRef $ref) {
     $commit = $this->commit;
     $author = $ref->getAuthor();
     $message = $ref->getMessage();
     $committer = $ref->getCommitter();
     $hashes = $ref->getHashes();
 
     $data = id(new PhabricatorRepositoryCommitData())->loadOneWhere(
       'commitID = %d',
       $commit->getID());
     if (!$data) {
       $data = new PhabricatorRepositoryCommitData();
     }
     $data->setCommitID($commit->getID());
     $data->setAuthorName(id(new PhutilUTF8StringTruncator())
       ->setMaximumCodepoints(255)
       ->truncateString((string)$author));
 
     $data->setCommitDetail('authorName', $ref->getAuthorName());
     $data->setCommitDetail('authorEmail', $ref->getAuthorEmail());
 
     $data->setCommitDetail(
       'authorPHID',
       $this->resolveUserPHID($commit, $author));
 
     $data->setCommitMessage($message);
 
     if (strlen($committer)) {
       $data->setCommitDetail('committer', $committer);
 
       $data->setCommitDetail('committerName', $ref->getCommitterName());
       $data->setCommitDetail('committerEmail', $ref->getCommitterEmail());
 
       $data->setCommitDetail(
         'committerPHID',
         $this->resolveUserPHID($commit, $committer));
     }
 
     $repository = $this->repository;
 
     $author_phid = $data->getCommitDetail('authorPHID');
     $committer_phid = $data->getCommitDetail('committerPHID');
 
     $user = new PhabricatorUser();
     if ($author_phid) {
       $user = $user->loadOneWhere(
         'phid = %s',
         $author_phid);
     }
 
     $differential_app = 'PhabricatorDifferentialApplication';
     $revision_id = null;
     $low_level_query = null;
     if (PhabricatorApplication::isClassInstalled($differential_app)) {
       $low_level_query = id(new DiffusionLowLevelCommitFieldsQuery())
         ->setRepository($repository)
         ->withCommitRef($ref);
       $field_values = $low_level_query->execute();
       $revision_id = idx($field_values, 'revisionID');
 
       if (!empty($field_values['reviewedByPHIDs'])) {
         $data->setCommitDetail(
           'reviewerPHID',
           reset($field_values['reviewedByPHIDs']));
       }
 
       $data->setCommitDetail('differential.revisionID', $revision_id);
     }
 
     if ($author_phid != $commit->getAuthorPHID()) {
       $commit->setAuthorPHID($author_phid);
     }
 
     $commit->setSummary($data->getSummary());
     $commit->save();
 
     // Figure out if we're going to try to "autoclose" related objects (e.g.,
     // close linked tasks and related revisions) and, if not, record why we
     // aren't. Autoclose can be disabled for various reasons at the repository
     // or commit levels.
 
     $autoclose_reason = $repository->shouldSkipAutocloseCommit($commit);
     $data->setCommitDetail('autocloseReason', $autoclose_reason);
     $should_autoclose = $repository->shouldAutocloseCommit($commit);
 
 
     // When updating related objects, we'll act under an omnipotent user to
     // ensure we can see them, but take actions as either the committer or
     // author (if we recognize their accounts) or the Diffusion application
     // (if we do not).
 
     $actor = PhabricatorUser::getOmnipotentUser();
     $acting_as_phid = nonempty(
       $committer_phid,
       $author_phid,
       id(new PhabricatorDiffusionApplication())->getPHID());
 
     $conn_w = id(new DifferentialRevision())->establishConnection('w');
 
     // NOTE: The `differential_commit` table has a unique ID on `commitPHID`,
     // preventing more than one revision from being associated with a commit.
     // Generally this is good and desirable, but with the advent of hash
     // tracking we may end up in a situation where we match several different
     // revisions. We just kind of ignore this and pick one, we might want to
     // revisit this and do something differently. (If we match several revisions
     // someone probably did something very silly, though.)
 
     $revision = null;
     if ($revision_id) {
       $revision_query = id(new DifferentialRevisionQuery())
         ->withIDs(array($revision_id))
         ->setViewer($actor)
         ->needReviewerStatus(true)
         ->needActiveDiffs(true);
 
       $revision = $revision_query->executeOne();
 
       if ($revision) {
         if (!$data->getCommitDetail('precommitRevisionStatus')) {
           $data->setCommitDetail(
             'precommitRevisionStatus',
             $revision->getStatus());
         }
         $commit_drev = PhabricatorEdgeConfig::TYPE_COMMIT_HAS_DREV;
         id(new PhabricatorEdgeEditor())
           ->addEdge($commit->getPHID(), $commit_drev, $revision->getPHID())
           ->save();
 
         queryfx(
           $conn_w,
           'INSERT IGNORE INTO %T (revisionID, commitPHID) VALUES (%d, %s)',
           DifferentialRevision::TABLE_COMMIT,
           $revision->getID(),
           $commit->getPHID());
 
         $status_closed = ArcanistDifferentialRevisionStatus::CLOSED;
         $should_close = ($revision->getStatus() != $status_closed) &&
                         $should_autoclose;
 
         if ($should_close) {
            $commit_close_xaction = id(new DifferentialTransaction())
             ->setTransactionType(DifferentialTransaction::TYPE_ACTION)
             ->setNewValue(DifferentialAction::ACTION_CLOSE)
             ->setMetadataValue('isCommitClose', true);
 
           $commit_close_xaction->setMetadataValue(
             'commitPHID',
             $commit->getPHID());
           $commit_close_xaction->setMetadataValue(
             'committerPHID',
             $committer_phid);
           $commit_close_xaction->setMetadataValue(
             'committerName',
             $data->getCommitDetail('committer'));
           $commit_close_xaction->setMetadataValue(
             'authorPHID',
             $author_phid);
           $commit_close_xaction->setMetadataValue(
             'authorName',
             $data->getAuthorName());
 
           if ($low_level_query) {
             $commit_close_xaction->setMetadataValue(
               'revisionMatchData',
               $low_level_query->getRevisionMatchData());
             $data->setCommitDetail(
               'revisionMatchData',
               $low_level_query->getRevisionMatchData());
           }
 
           $diff = $this->generateFinalDiff($revision, $acting_as_phid);
 
           $vs_diff = $this->loadChangedByCommit($revision, $diff);
           $changed_uri = null;
           if ($vs_diff) {
             $data->setCommitDetail('vsDiff', $vs_diff->getID());
 
             $changed_uri = PhabricatorEnv::getProductionURI(
               '/D'.$revision->getID().
               '?vs='.$vs_diff->getID().
               '&id='.$diff->getID().
               '#toc');
           }
 
           $xactions = array();
           $xactions[] = id(new DifferentialTransaction())
             ->setTransactionType(DifferentialTransaction::TYPE_UPDATE)
             ->setIgnoreOnNoEffect(true)
             ->setNewValue($diff->getPHID())
             ->setMetadataValue('isCommitUpdate', true);
           $xactions[] = $commit_close_xaction;
 
           $content_source = PhabricatorContentSource::newForSource(
             PhabricatorContentSource::SOURCE_DAEMON,
             array());
 
           $editor = id(new DifferentialTransactionEditor())
             ->setActor($actor)
             ->setActingAsPHID($acting_as_phid)
             ->setContinueOnMissingFields(true)
             ->setContentSource($content_source)
             ->setChangedPriorToCommitURI($changed_uri)
             ->setIsCloseByCommit(true);
 
           try {
             $editor->applyTransactions($revision, $xactions);
           } catch (PhabricatorApplicationTransactionNoEffectException $ex) {
             // NOTE: We've marked transactions other than the CLOSE transaction
             // as ignored when they don't have an effect, so this means that we
             // lost a race to close the revision. That's perfectly fine, we can
             // just continue normally.
           }
         }
       }
     }
 
     if ($should_autoclose) {
       $this->closeTasks(
         $actor,
         $acting_as_phid,
         $repository,
         $commit,
         $message);
     }
 
     $data->save();
 
     $commit->writeImportStatusFlag(
       PhabricatorRepositoryCommit::IMPORTED_MESSAGE);
   }
 
   private function generateFinalDiff(
     DifferentialRevision $revision,
     $actor_phid) {
 
     $viewer = PhabricatorUser::getOmnipotentUser();
 
     $drequest = DiffusionRequest::newFromDictionary(array(
       'user' => $viewer,
       'repository' => $this->repository,
     ));
 
     $raw_diff = DiffusionQuery::callConduitWithDiffusionRequest(
       $viewer,
       $drequest,
       'diffusion.rawdiffquery',
       array(
         'commit' => $this->commit->getCommitIdentifier(),
       ));
 
     // TODO: Support adds, deletes and moves under SVN.
     if (strlen($raw_diff)) {
       $changes = id(new ArcanistDiffParser())->parseDiff($raw_diff);
     } else {
       // This is an empty diff, maybe made with `git commit --allow-empty`.
       // NOTE: These diffs have the same tree hash as their ancestors, so
       // they may attach to revisions in an unexpected way. Just let this
       // happen for now, although it might make sense to special case it
       // eventually.
       $changes = array();
     }
 
-    $diff = DifferentialDiff::newFromRawChanges($changes)
+    $diff = DifferentialDiff::newFromRawChanges($viewer, $changes)
       ->setRepositoryPHID($this->repository->getPHID())
       ->setAuthorPHID($actor_phid)
       ->setCreationMethod('commit')
       ->setSourceControlSystem($this->repository->getVersionControlSystem())
       ->setLintStatus(DifferentialLintStatus::LINT_AUTO_SKIP)
       ->setUnitStatus(DifferentialUnitStatus::UNIT_AUTO_SKIP)
       ->setDateCreated($this->commit->getEpoch())
       ->setDescription(
         'Commit r'.
         $this->repository->getCallsign().
         $this->commit->getCommitIdentifier());
 
     // TODO: This is not correct in SVN where one repository can have multiple
     // Arcanist projects.
     $arcanist_project = id(new PhabricatorRepositoryArcanistProject())
       ->loadOneWhere('repositoryID = %d LIMIT 1', $this->repository->getID());
     if ($arcanist_project) {
       $diff->setArcanistProjectPHID($arcanist_project->getPHID());
     }
 
     $parents = DiffusionQuery::callConduitWithDiffusionRequest(
       $viewer,
       $drequest,
       'diffusion.commitparentsquery',
       array(
         'commit' => $this->commit->getCommitIdentifier(),
       ));
     if ($parents) {
       $diff->setSourceControlBaseRevision(head($parents));
     }
 
     // TODO: Attach binary files.
 
     return $diff->save();
   }
 
   private function loadChangedByCommit(
     DifferentialRevision $revision,
     DifferentialDiff $diff) {
 
     $repository = $this->repository;
 
     $vs_diff = id(new DifferentialDiffQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withRevisionIDs(array($revision->getID()))
       ->needChangesets(true)
       ->setLimit(1)
       ->executeOne();
     if (!$vs_diff) {
       return null;
     }
 
     if ($vs_diff->getCreationMethod() == 'commit') {
       return null;
     }
 
     $vs_changesets = array();
     foreach ($vs_diff->getChangesets() as $changeset) {
       $path = $changeset->getAbsoluteRepositoryPath($repository, $vs_diff);
       $path = ltrim($path, '/');
       $vs_changesets[$path] = $changeset;
     }
 
     $changesets = array();
     foreach ($diff->getChangesets() as $changeset) {
       $path = $changeset->getAbsoluteRepositoryPath($repository, $diff);
       $path = ltrim($path, '/');
       $changesets[$path] = $changeset;
     }
 
     if (array_fill_keys(array_keys($changesets), true) !=
         array_fill_keys(array_keys($vs_changesets), true)) {
       return $vs_diff;
     }
 
     $file_phids = array();
     foreach ($vs_changesets as $changeset) {
       $metadata = $changeset->getMetadata();
       $file_phid = idx($metadata, 'new:binary-phid');
       if ($file_phid) {
         $file_phids[$file_phid] = $file_phid;
       }
     }
 
     $files = array();
     if ($file_phids) {
       $files = id(new PhabricatorFileQuery())
         ->setViewer(PhabricatorUser::getOmnipotentUser())
         ->withPHIDs($file_phids)
         ->execute();
       $files = mpull($files, null, 'getPHID');
     }
 
     foreach ($changesets as $path => $changeset) {
       $vs_changeset = $vs_changesets[$path];
 
       $file_phid = idx($vs_changeset->getMetadata(), 'new:binary-phid');
       if ($file_phid) {
         if (!isset($files[$file_phid])) {
           return $vs_diff;
         }
         $drequest = DiffusionRequest::newFromDictionary(array(
           'user' => PhabricatorUser::getOmnipotentUser(),
           'initFromConduit' => false,
           'repository' => $this->repository,
           'commit' => $this->commit->getCommitIdentifier(),
           'path' => $path,
         ));
         $corpus = DiffusionFileContentQuery::newFromDiffusionRequest($drequest)
           ->setViewer(PhabricatorUser::getOmnipotentUser())
           ->loadFileContent()
           ->getCorpus();
         if ($files[$file_phid]->loadFileData() != $corpus) {
           return $vs_diff;
         }
       } else {
         $context = implode("\n", $changeset->makeChangesWithContext());
         $vs_context = implode("\n", $vs_changeset->makeChangesWithContext());
 
         // We couldn't just compare $context and $vs_context because following
         // diffs will be considered different:
         //
         //   -(empty line)
         //   -echo 'test';
         //    (empty line)
         //
         //    (empty line)
         //   -echo "test";
         //   -(empty line)
 
         $hunk = id(new DifferentialHunkModern())->setChanges($context);
         $vs_hunk = id(new DifferentialHunkModern())->setChanges($vs_context);
         if ($hunk->makeOldFile() != $vs_hunk->makeOldFile() ||
             $hunk->makeNewFile() != $vs_hunk->makeNewFile()) {
           return $vs_diff;
         }
       }
     }
 
     return null;
   }
 
   private function resolveUserPHID(
     PhabricatorRepositoryCommit $commit,
     $user_name) {
 
     return id(new DiffusionResolveUserQuery())
       ->withCommit($commit)
       ->withName($user_name)
       ->execute();
   }
 
   private function closeTasks(
     PhabricatorUser $actor,
     $acting_as,
     PhabricatorRepository $repository,
     PhabricatorRepositoryCommit $commit,
     $message) {
 
     $maniphest = 'PhabricatorManiphestApplication';
     if (!PhabricatorApplication::isClassInstalled($maniphest)) {
       return;
     }
 
     $prefixes = ManiphestTaskStatus::getStatusPrefixMap();
     $suffixes = ManiphestTaskStatus::getStatusSuffixMap();
 
     $matches = id(new ManiphestCustomFieldStatusParser())
       ->parseCorpus($message);
 
     $task_statuses = array();
     foreach ($matches as $match) {
       $prefix = phutil_utf8_strtolower($match['prefix']);
       $suffix = phutil_utf8_strtolower($match['suffix']);
 
       $status = idx($suffixes, $suffix);
       if (!$status) {
         $status = idx($prefixes, $prefix);
       }
 
       foreach ($match['monograms'] as $task_monogram) {
         $task_id = (int)trim($task_monogram, 'tT');
         $task_statuses[$task_id] = $status;
       }
     }
 
     if (!$task_statuses) {
       return;
     }
 
     $tasks = id(new ManiphestTaskQuery())
       ->setViewer($actor)
       ->withIDs(array_keys($task_statuses))
       ->execute();
 
     foreach ($tasks as $task_id => $task) {
       $xactions = array();
 
       $edge_type = ManiphestTaskHasCommitEdgeType::EDGECONST;
       $xactions[] = id(new ManiphestTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
         ->setMetadataValue('edge:type', $edge_type)
         ->setNewValue(
           array(
             '+' => array(
               $commit->getPHID() => $commit->getPHID(),
             ),
           ));
 
       $status = $task_statuses[$task_id];
       if ($status) {
         if ($task->getStatus() != $status) {
           $xactions[] = id(new ManiphestTransaction())
             ->setTransactionType(ManiphestTransaction::TYPE_STATUS)
             ->setNewValue($status);
 
           $commit_name = $repository->formatCommitName(
             $commit->getCommitIdentifier());
 
           $status_message = pht(
             'Closed by commit %s.',
             $commit_name);
 
           $xactions[] = id(new ManiphestTransaction())
             ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
             ->attachComment(
               id(new ManiphestTransactionComment())
                 ->setContent($status_message));
         }
       }
 
       $content_source = PhabricatorContentSource::newForSource(
         PhabricatorContentSource::SOURCE_DAEMON,
         array());
 
       $editor = id(new ManiphestTransactionEditor())
         ->setActor($actor)
         ->setActingAsPHID($acting_as)
         ->setContinueOnNoEffect(true)
         ->setContinueOnMissingFields(true)
         ->setUnmentionablePHIDMap(
           array($commit->getPHID() => $commit->getPHID()))
         ->setContentSource($content_source);
 
       $editor->applyTransactions($task, $xactions);
     }
   }
 
 }
diff --git a/src/infrastructure/diff/PhabricatorDifferenceEngine.php b/src/infrastructure/diff/PhabricatorDifferenceEngine.php
index 8c2bf08c7b..b7b22d7da0 100644
--- a/src/infrastructure/diff/PhabricatorDifferenceEngine.php
+++ b/src/infrastructure/diff/PhabricatorDifferenceEngine.php
@@ -1,170 +1,172 @@
 <?php
 
 /**
  * Utility class which encapsulates some shared behavior between different
  * applications which render diffs.
  *
  * @task config Configuring the Engine
  * @task diff Generating Diffs
  */
 final class PhabricatorDifferenceEngine {
 
 
   private $ignoreWhitespace;
   private $oldName;
   private $newName;
 
 
 /* -(  Configuring the Engine  )--------------------------------------------- */
 
 
   /**
    * If true, ignore whitespace when computing differences.
    *
    * @param bool Ignore whitespace?
    * @return this
    * @task config
    */
   public function setIgnoreWhitespace($ignore_whitespace) {
     $this->ignoreWhitespace = $ignore_whitespace;
     return $this;
   }
 
 
   /**
    * Set the name to identify the old file with. Primarily cosmetic.
    *
    * @param  string Old file name.
    * @return this
    * @task config
    */
   public function setOldName($old_name) {
     $this->oldName = $old_name;
     return $this;
   }
 
 
   /**
    * Set the name to identify the new file with. Primarily cosmetic.
    *
    * @param  string New file name.
    * @return this
    * @task config
    */
   public function setNewName($new_name) {
     $this->newName = $new_name;
     return $this;
   }
 
 
 /* -(  Generating Diffs  )--------------------------------------------------- */
 
 
   /**
    * Generate a raw diff from two raw files. This is a lower-level API than
    * @{method:generateChangesetFromFileContent}, but may be useful if you need
    * to use a custom parser configuration, as with Diffusion.
    *
    * @param string Entire previous file content.
    * @param string Entire current file content.
    * @return string Raw diff between the two files.
    * @task diff
    */
   public function generateRawDiffFromFileContent($old, $new) {
 
     $options = array();
     if ($this->ignoreWhitespace) {
       $options[] = '-bw';
     }
 
     // Generate diffs with full context.
     $options[] = '-U65535';
 
     $old_name = nonempty($this->oldName, '/dev/universe').' 9999-99-99';
     $new_name = nonempty($this->newName, '/dev/universe').' 9999-99-99';
 
     $options[] = '-L';
     $options[] = $old_name;
     $options[] = '-L';
     $options[] = $new_name;
 
     $old_tmp = new TempFile();
     $new_tmp = new TempFile();
 
     Filesystem::writeFile($old_tmp, $old);
     Filesystem::writeFile($new_tmp, $new);
     list($err, $diff) = exec_manual(
       'diff %Ls %s %s',
       $options,
       $old_tmp,
       $new_tmp);
 
     if (!$err) {
       // This indicates that the two files are the same (or, possibly, the
       // same modulo whitespace differences, which is why we can't do this
       // check trivially before running `diff`). Build a synthetic, changeless
       // diff so that we can still render the raw, unchanged file instead of
       // being forced to just say "this file didn't change" since we don't have
       // the content.
 
       $entire_file = explode("\n", $old);
       foreach ($entire_file as $k => $line) {
         $entire_file[$k] = ' '.$line;
       }
 
       $len = count($entire_file);
       $entire_file = implode("\n", $entire_file);
 
       // TODO: If both files were identical but missing newlines, we probably
       // get this wrong. Unclear if it ever matters.
 
       // This is a bit hacky but the diff parser can handle it.
       $diff = "--- {$old_name}\n".
               "+++ {$new_name}\n".
               "@@ -1,{$len} +1,{$len} @@\n".
               $entire_file."\n";
     } else {
       if ($this->ignoreWhitespace) {
 
         // Under "-bw", `diff` is inconsistent about emitting "\ No newline
         // at end of file". For instance, a long file with a change in the
         // middle will emit a contextless "\ No newline..." at the end if a
         // newline is removed, but not if one is added. A file with a change
         // at the end will emit the "old" "\ No newline..." block only, even
         // if the newline was not removed. Since we're ostensibly ignoring
         // whitespace changes, just drop these lines if they appear anywhere
         // in the diff.
 
         $lines = explode("\n", $diff);
         foreach ($lines as $key => $line) {
           if (isset($line[0]) && $line[0] == '\\') {
             unset($lines[$key]);
           }
         }
         $diff = implode("\n", $lines);
       }
     }
 
     return $diff;
   }
 
 
   /**
    * Generate an @{class:DifferentialChangeset} from two raw files. This is
    * principally useful because you can feed the output to
    * @{class:DifferentialChangesetParser} in order to render it.
    *
    * @param string Entire previous file content.
    * @param string Entire current file content.
    * @return @{class:DifferentialChangeset} Synthetic changeset.
    * @task diff
    */
   public function generateChangesetFromFileContent($old, $new) {
     $diff = $this->generateRawDiffFromFileContent($old, $new);
 
     $changes = id(new ArcanistDiffParser())->parseDiff($diff);
-    $diff = DifferentialDiff::newFromRawChanges($changes);
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $changes);
     return head($diff->getChangesets());
   }
 
 }