diff --git a/src/applications/differential/controller/DifferentialCommentSaveControllerPro.php b/src/applications/differential/controller/DifferentialCommentSaveControllerPro.php
index 6b730a5146..6521995577 100644
--- a/src/applications/differential/controller/DifferentialCommentSaveControllerPro.php
+++ b/src/applications/differential/controller/DifferentialCommentSaveControllerPro.php
@@ -1,181 +1,182 @@
 <?php
 
 final class DifferentialCommentSaveControllerPro
   extends DifferentialController {
 
   private $id;
 
   public function willProcessRequest(array $data) {
     $this->id = $data['id'];
   }
 
   public function processRequest() {
     $request = $this->getRequest();
     $viewer = $request->getUser();
 
     if (!$request->isFormPost()) {
       return new Aphront400Response();
     }
 
     $revision = id(new DifferentialRevisionQuery())
       ->setViewer($viewer)
       ->withIDs(array($this->id))
       ->needReviewerStatus(true)
+      ->needReviewerAuthority(true)
       ->executeOne();
     if (!$revision) {
       return new Aphront404Response();
     }
 
     $type_action = DifferentialTransaction::TYPE_ACTION;
     $type_subscribers = PhabricatorTransactions::TYPE_SUBSCRIBERS;
     $type_edge = PhabricatorTransactions::TYPE_EDGE;
     $type_comment = PhabricatorTransactions::TYPE_COMMENT;
     $type_inline = DifferentialTransaction::TYPE_INLINE;
 
     $edge_reviewer = PhabricatorEdgeConfig::TYPE_DREV_HAS_REVIEWER;
 
     $xactions = array();
 
     $action = $request->getStr('action');
     switch ($action) {
       case DifferentialAction::ACTION_COMMENT:
       case DifferentialAction::ACTION_ADDREVIEWERS:
       case DifferentialAction::ACTION_ADDCCS:
         // These transaction types have no direct effect, they just
         // accompany other transaction types which can have an effect.
         break;
       default:
         $xactions[] = id(new DifferentialTransaction())
           ->setTransactionType($type_action)
           ->setNewValue($request->getStr('action'));
         break;
     }
 
     $ccs = $request->getArr('ccs');
     if ($ccs) {
       $xactions[] = id(new DifferentialTransaction())
         ->setTransactionType($type_subscribers)
         ->setNewValue(array('+' => $ccs));
     }
 
     $current_reviewers = mpull(
       $revision->getReviewerStatus(),
       null,
       'getReviewerPHID');
 
     $reviewer_edges = array();
     $add_reviewers = $request->getArr('reviewers');
     foreach ($add_reviewers as $reviewer_phid) {
       if (isset($current_reviewers[$reviewer_phid])) {
         continue;
       }
       $reviewer = new DifferentialReviewer(
         $reviewer_phid,
         array(
           'status' => DifferentialReviewerStatus::STATUS_ADDED,
         ));
       $reviewer_edges[$reviewer_phid] = array(
         'data' => $reviewer->getEdgeData(),
       );
     }
 
     if ($add_reviewers) {
       $xactions[] = id(new DifferentialTransaction())
         ->setTransactionType($type_edge)
         ->setMetadataValue('edge:type', $edge_reviewer)
         ->setNewValue(array('+' => $reviewer_edges));
     }
 
     $inline_phids = $this->loadUnsubmittedInlinePHIDs($revision);
     if ($inline_phids) {
       $inlines = id(new PhabricatorApplicationTransactionCommentQuery())
         ->setTemplate(new DifferentialTransactionComment())
         ->setViewer($viewer)
         ->withPHIDs($inline_phids)
         ->execute();
     } else {
       $inlines = array();
     }
 
     foreach ($inlines as $inline) {
       $xactions[] = id(new DifferentialTransaction())
         ->setTransactionType($type_inline)
         ->attachComment($inline);
     }
 
     // NOTE: If there are no other transactions, add an empty comment
     // transaction so that we'll raise a more user-friendly error message,
     // to the effect of "you can not post an empty comment".
     $no_xactions = !$xactions;
 
     $comment = $request->getStr('comment');
     if (strlen($comment) || $no_xactions) {
       $xactions[] = id(new DifferentialTransaction())
         ->setTransactionType($type_comment)
         ->attachComment(
           id(new DifferentialTransactionComment())
             ->setRevisionPHID($revision->getPHID())
             ->setContent($comment));
     }
 
 
     $editor = id(new DifferentialTransactionEditor())
       ->setActor($viewer)
       ->setContentSourceFromRequest($request)
       ->setContinueOnMissingFields(true)
       ->setContinueOnNoEffect($request->isContinueRequest());
 
     $revision_uri = '/D'.$revision->getID();
 
     try {
       $editor->applyTransactions($revision, $xactions);
     } catch (PhabricatorApplicationTransactionNoEffectException $ex) {
       return id(new PhabricatorApplicationTransactionNoEffectResponse())
         ->setCancelURI($revision_uri)
         ->setException($ex);
     } catch (PhabricatorApplicationTransactionValidationException $ex) {
       // TODO: Provide a nice Response for rendering these in a clean way.
       throw $ex;
     }
 
     $user = $request->getUser();
     $draft = id(new PhabricatorDraft())->loadOneWhere(
       'authorPHID = %s AND draftKey = %s',
       $user->getPHID(),
       'differential-comment-'.$revision->getID());
     if ($draft) {
       $draft->delete();
     }
     DifferentialDraft::deleteAllDrafts($user->getPHID(), $revision->getPHID());
 
     return id(new AphrontRedirectResponse())
       ->setURI('/D'.$revision->getID());
   }
 
 
   private function loadUnsubmittedInlinePHIDs(DifferentialRevision $revision) {
     $viewer = $this->getRequest()->getUser();
 
     // TODO: This probably needs to move somewhere more central as we move
     // away from DifferentialInlineCommentQuery, but
     // PhabricatorApplicationTransactionCommentQuery is currently `final` and
     // I'm not yet decided on how to approach that. For now, just get the PHIDs
     // and then execute a PHID-based query through the standard stack.
 
     $table = new DifferentialTransactionComment();
     $conn_r = $table->establishConnection('r');
 
     $phids = queryfx_all(
       $conn_r,
       'SELECT phid FROM %T
         WHERE revisionPHID = %s
           AND authorPHID = %s
           AND transactionPHID IS NULL',
       $table->getTableName(),
       $revision->getPHID(),
       $viewer->getPHID());
 
     return ipull($phids, 'phid');
   }
 
 }
diff --git a/src/applications/differential/editor/DifferentialTransactionEditor.php b/src/applications/differential/editor/DifferentialTransactionEditor.php
index e3202e4e50..1dc1985b0c 100644
--- a/src/applications/differential/editor/DifferentialTransactionEditor.php
+++ b/src/applications/differential/editor/DifferentialTransactionEditor.php
@@ -1,546 +1,653 @@
 <?php
 
 final class DifferentialTransactionEditor
   extends PhabricatorApplicationTransactionEditor {
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
     $types[] = PhabricatorTransactions::TYPE_EDGE;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
 
     $types[] = DifferentialTransaction::TYPE_ACTION;
     $types[] = DifferentialTransaction::TYPE_INLINE;
 
 /*
 
     $types[] = DifferentialTransaction::TYPE_UPDATE;
 */
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return $object->getViewPolicy();
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return $object->getEditPolicy();
       case DifferentialTransaction::TYPE_ACTION:
         return null;
       case DifferentialTransaction::TYPE_INLINE:
         return null;
     }
 
     return parent::getCustomTransactionOldValue($object, $xaction);
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case DifferentialTransaction::TYPE_ACTION:
         return $xaction->getNewValue();
       case DifferentialTransaction::TYPE_INLINE:
         return null;
     }
 
     return parent::getCustomTransactionNewValue($object, $xaction);
   }
 
   protected function transactionHasEffect(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_INLINE:
         return $xaction->hasComment();
       case DifferentialTransaction::TYPE_ACTION:
         $status_closed = ArcanistDifferentialRevisionStatus::CLOSED;
         $status_abandoned = ArcanistDifferentialRevisionStatus::ABANDONED;
         $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
         $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
 
-        switch ($xaction->getNewValue()) {
+        $action_type = $xaction->getNewValue();
+        switch ($action_type) {
+          case DifferentialAction::ACTION_ACCEPT:
+          case DifferentialAction::ACTION_REJECT:
+            if ($action_type == DifferentialAction::ACTION_ACCEPT) {
+              $new_status = DifferentialReviewerStatus::STATUS_ACCEPTED;
+            } else {
+              $new_status = DifferentialReviewerStatus::STATUS_REJECTED;
+            }
+
+            $actor = $this->getActor();
+            $actor_phid = $actor->getPHID();
+
+            // These transactions can cause effects in to ways: by altering the
+            // status of an existing reviewer; or by adding the actor as a new
+            // reviewer.
+
+            $will_add_reviewer = true;
+            foreach ($object->getReviewerStatus() as $reviewer) {
+              if ($reviewer->hasAuthority($actor)) {
+                if ($reviewer->getStatus() != $new_status) {
+                  return true;
+                }
+              }
+              if ($reviewer->getReviewerPHID() == $actor_phid) {
+                $will_add_reviwer = false;
+              }
+            }
+
+            return $will_add_reviewer;
           case DifferentialAction::ACTION_CLOSE:
             return ($object->getStatus() != $status_closed);
           case DifferentialAction::ACTION_ABANDON:
             return ($object->getStatus() != $status_abandoned);
           case DifferentialAction::ACTION_RECLAIM:
             return ($object->getStatus() == $status_abandoned);
           case DifferentialAction::ACTION_REOPEN:
             return ($object->getStatus() == $status_closed);
           case DifferentialAction::ACTION_RETHINK:
             return ($object->getStatus() != $status_revision);
           case DifferentialAction::ACTION_REQUEST:
             return ($object->getStatus() != $status_review);
           case DifferentialAction::ACTION_RESIGN:
             $actor_phid = $this->getActor()->getPHID();
             foreach ($object->getReviewerStatus() as $reviewer) {
               if ($reviewer->getReviewerPHID() == $actor_phid) {
                 return true;
               }
             }
             return false;
           case DifferentialAction::ACTION_CLAIM:
             $actor_phid = $this->getActor()->getPHID();
             return ($actor_phid != $object->getAuthorPHID());
         }
     }
 
     return parent::transactionHasEffect($object, $xaction);
   }
 
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         $object->setViewPolicy($xaction->getNewValue());
         return;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $object->setEditPolicy($xaction->getNewValue());
         return;
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
       case PhabricatorTransactions::TYPE_COMMENT:
       case DifferentialTransaction::TYPE_INLINE:
         return;
       case PhabricatorTransactions::TYPE_EDGE:
-        // TODO: When removing reviewers, we may be able to move the revision
-        // to "Accepted".
+        // TODO: Update review status.
         return;
       case DifferentialTransaction::TYPE_ACTION:
         $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
         $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
 
         switch ($xaction->getNewValue()) {
           case DifferentialAction::ACTION_RESIGN:
-            // TODO: Update review status?
-            break;
+          case DifferentialAction::ACTION_ACCEPT:
+          case DifferentialAction::ACTION_REJECT:
+            // These have no direct effects, and affect review status only
+            // indirectly by altering reviewers with TYPE_EDGE transactions.
+            return;
           case DifferentialAction::ACTION_ABANDON:
             $object->setStatus(ArcanistDifferentialRevisionStatus::ABANDONED);
-            break;
+            return;
           case DifferentialAction::ACTION_RETHINK:
             $object->setStatus($status_revision);
-            break;
+            return;
           case DifferentialAction::ACTION_RECLAIM:
             $object->setStatus($status_review);
             // TODO: Update review status?
-            break;
+            return;
           case DifferentialAction::ACTION_REOPEN:
             $object->setStatus($status_review);
             // TODO: Update review status?
-            break;
+            return;
           case DifferentialAction::ACTION_REQUEST:
             $object->setStatus($status_review);
             // TODO: Update review status?
-            break;
+            return;
           case DifferentialAction::ACTION_CLOSE:
             $object->setStatus(ArcanistDifferentialRevisionStatus::CLOSED);
-            break;
+            return;
           case DifferentialAction::ACTION_CLAIM:
             $object->setAuthorPHID($this->getActor()->getPHID());
-            break;
-          default:
-            // TODO: For now, we're just shipping the rest of these through
-            // without acting on them.
-            break;
+            return;
         }
-        return null;
+        break;
     }
 
     return parent::applyCustomInternalTransaction($object, $xaction);
   }
 
   protected function expandTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $results = parent::expandTransaction($object, $xaction);
     switch ($xaction->getTransactionType()) {
+      // TODO: If the user comments and is a reviewer, we should upgrade their
+      // edge metadata to STATUS_COMMENTED.
+
       case DifferentialTransaction::TYPE_ACTION:
 
-        $actor_phid = $this->getActor()->getPHID();
+        $actor = $this->getActor();
+        $actor_phid = $actor->getPHID();
         $type_edge = PhabricatorTransactions::TYPE_EDGE;
         $edge_reviewer = PhabricatorEdgeConfig::TYPE_DREV_HAS_REVIEWER;
+        $action_type = $xaction->getNewValue();
+
+        switch ($action_type) {
+          case DifferentialAction::ACTION_ACCEPT:
+          case DifferentialAction::ACTION_REJECT:
+            if ($action_type == DifferentialAction::ACTION_ACCEPT) {
+              $data = array(
+                'status' => DifferentialReviewerStatus::STATUS_ACCEPTED,
+              );
+            } else {
+              $data = array(
+                'status' => DifferentialReviewerStatus::STATUS_REJECTED,
+              );
+            }
+
+            $edits = array();
+
+            foreach ($object->getReviewerStatus() as $reviewer) {
+              if ($reviewer->hasAuthority($actor)) {
+                $edits[$reviewer->getReviewerPHID()] = array(
+                  'data' => $data,
+                );
+              }
+            }
+
+            // Also either update or add the actor themselves as a reviewer.
+            $edits[$actor_phid] = array(
+              'data' => $data,
+            );
+
+            $results[] = id(new DifferentialTransaction())
+              ->setTransactionType($type_edge)
+              ->setMetadataValue('edge:type', $edge_reviewer)
+              ->setIgnoreOnNoEffect(true)
+              ->setNewValue(array('+' => $edits));
+            break;
 
-        switch ($xaction->getNewValue()) {
           case DifferentialAction::ACTION_CLAIM:
             // If the user is commandeering, add the previous owner as a
             // reviewer and remove the actor.
 
             $edits = array(
               '-' => array(
                 $actor_phid => $actor_phid,
               ),
             );
 
             $owner_phid = $object->getAuthorPHID();
             if ($owner_phid) {
               $reviewer = new DifferentialReviewer(
                 $owner_phid,
                 array(
                   'status' => DifferentialReviewerStatus::STATUS_ADDED,
                 ));
 
               $edits['+'] = array(
                 $owner_phid => array(
                   'data' => $reviewer->getEdgeData(),
                 ),
               );
             }
 
             $results[] = id(new DifferentialTransaction())
               ->setTransactionType($type_edge)
               ->setMetadataValue('edge:type', $edge_reviewer)
               ->setIgnoreOnNoEffect(true)
               ->setNewValue($edits);
 
             break;
           case DifferentialAction::ACTION_RESIGN:
             // If the user is resigning, add a separate reviewer edit
             // transaction which removes them as a reviewer.
 
             $results[] = id(new DifferentialTransaction())
               ->setTransactionType($type_edge)
               ->setMetadataValue('edge:type', $edge_reviewer)
               ->setIgnoreOnNoEffect(true)
               ->setNewValue(
                 array(
                   '-' => array(
                     $actor_phid => $actor_phid,
                   ),
                 ));
 
             break;
         }
       break;
     }
 
     return $results;
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return;
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
       case PhabricatorTransactions::TYPE_EDGE:
       case PhabricatorTransactions::TYPE_COMMENT:
       case DifferentialTransaction::TYPE_ACTION:
       case DifferentialTransaction::TYPE_INLINE:
         return;
     }
 
     return parent::applyCustomExternalTransaction($object, $xaction);
   }
 
   protected function validateTransaction(
     PhabricatorLiskDAO $object,
     $type,
     array $xactions) {
 
     $errors = parent::validateTransaction($object, $type, $xactions);
 
     foreach ($xactions as $xaction) {
       switch ($type) {
         case DifferentialTransaction::TYPE_ACTION:
           $error = $this->validateDifferentialAction(
             $object,
             $type,
             $xaction,
             $xaction->getNewValue());
           if ($error) {
             $errors[] = new PhabricatorApplicationTransactionValidationError(
               $type,
               pht('Invalid'),
               $error,
               $xaction);
           }
           break;
       }
     }
 
     return $errors;
   }
 
   private function validateDifferentialAction(
     DifferentialRevision $revision,
     $type,
     DifferentialTransaction $xaction,
     $action) {
 
     $author_phid = $revision->getAuthorPHID();
     $actor_phid = $this->getActor()->getPHID();
     $actor_is_author = ($author_phid == $actor_phid);
 
     $config_close_key = 'differential.always-allow-close';
     $always_allow_close = PhabricatorEnv::getEnvConfig($config_close_key);
 
     $config_reopen_key = 'differential.allow-reopen';
     $allow_reopen = PhabricatorEnv::getEnvConfig($config_reopen_key);
 
+    $config_self_accept_key = 'differential.allow-self-accept';
+    $allow_self_accept = PhabricatorEnv::getEnvConfig($config_self_accept_key);
+
     $revision_status = $revision->getStatus();
 
     $status_accepted = ArcanistDifferentialRevisionStatus::ACCEPTED;
     $status_abandoned = ArcanistDifferentialRevisionStatus::ABANDONED;
     $status_closed = ArcanistDifferentialRevisionStatus::CLOSED;
 
     switch ($action) {
+      case DifferentialAction::ACTION_ACCEPT:
+        if ($actor_is_author && !$allow_self_accept) {
+          return pht(
+            'You can not accept this revision because you are the owner.');
+        }
+
+        if ($revision_status == $status_abandoned) {
+          return pht(
+            'You can not accept this revision because it has been '.
+            'abandoned.');
+        }
+
+        if ($revision_status == $status_closed) {
+          return pht(
+            'You can not accept this revision because it has already been '.
+            'closed.');
+        }
+        break;
+
+      case DifferentialAction::ACTION_REJECT:
+        if ($actor_is_author) {
+          return pht(
+            'You can not request changes to your own revision.');
+        }
+
+        if ($revision_status == $status_abandoned) {
+          return pht(
+            'You can not request changes to this revision because it has been '.
+            'abandoned.');
+        }
+
+        if ($revision_status == $status_closed) {
+          return pht(
+            'You can not request changes to this revision because it has '.
+            'already been closed.');
+        }
+        break;
+
       case DifferentialAction::ACTION_RESIGN:
         // You can always resign from a revision if you're a reviewer. If you
         // aren't, this is a no-op rather than invalid.
         break;
 
       case DifferentialAction::ACTION_CLAIM:
         // You can claim a revision if you're not the owner. If you are, this
         // is a no-op rather than invalid.
 
         if ($revision_status == $status_closed) {
           return pht(
             "You can not commandeer this revision because it has already been ".
             "closed.");
         }
         break;
 
       case DifferentialAction::ACTION_ABANDON:
         if (!$actor_is_author) {
           return pht(
             "You can not abandon this revision because you do not own it. ".
             "You can only abandon revisions you own.");
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             "You can not abandon this revision because it has already been ".
             "closed.");
         }
 
         // NOTE: Abandons of already-abandoned revisions are treated as no-op
         // instead of invalid. Other abandons are OK.
 
         break;
 
       case DifferentialAction::ACTION_RECLAIM:
         if (!$actor_is_author) {
           return pht(
             "You can not reclaim this revision because you do not own ".
             "it. You can only reclaim revisions you own.");
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             "You can not reclaim this revision because it has already been ".
             "closed.");
         }
 
         // NOTE: Reclaims of other non-abandoned revisions are treated as no-op
         // instead of invalid.
 
         break;
 
       case DifferentialAction::ACTION_REOPEN:
         if (!$allow_reopen) {
           return pht(
             'The reopen action is not enabled on this Phabricator install. '.
             'Adjust your configuration to enable it.');
         }
 
         // NOTE: If the revision is not closed, this is caught as a no-op
         // instead of an invalid transaction.
 
         break;
 
       case DifferentialAction::ACTION_RETHINK:
         if (!$actor_is_author) {
           return pht(
             "You can not plan changes to this revision because you do not ".
             "own it. To plan chagnes to a revision, you must be its owner.");
         }
 
         switch ($revision_status) {
           case ArcanistDifferentialRevisionStatus::ACCEPTED:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVISION:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVIEW:
             // These are OK.
             break;
           case ArcanistDifferentialRevisionStatus::ABANDONED:
             return pht(
               "You can not plan changes to this revision because it has ".
               "been abandoned.");
           case ArcanistDifferentialRevisionStatus::CLOSED:
             return pht(
               "You can not plan changes to this revision because it has ".
               "already been closed.");
           default:
             throw new Exception(
               pht(
                 'Encountered unexpected revision status ("%s") when '.
                 'validating "%s" action.',
                 $revision_status,
                 $action));
         }
         break;
 
       case DifferentialAction::ACTION_REQUEST:
         if (!$actor_is_author) {
           return pht(
             "You can not request review of this revision because you do ".
             "not own it. To request review of a revision, you must be its ".
             "owner.");
         }
 
         switch ($revision_status) {
           case ArcanistDifferentialRevisionStatus::ACCEPTED:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVISION:
             // These are OK.
             break;
           case ArcanistDifferentialRevisionStatus::NEEDS_REVIEW:
             // This will be caught as "no effect" later on.
             break;
           case ArcanistDifferentialRevisionStatus::ABANDONED:
             return pht(
               "You can not request review of this revision because it has ".
               "been abandoned. Instead, reclaim it.");
           case ArcanistDifferentialRevisionStatus::CLOSED:
             return pht(
               "You can not request review of this revision because it has ".
               "already been closed.");
           default:
             throw new Exception(
               pht(
                 'Encountered unexpected revision status ("%s") when '.
                 'validating "%s" action.',
                 $revision_status,
                 $action));
         }
         break;
 
       case DifferentialAction::ACTION_CLOSE:
 
         // TODO: Permit the daemons to take this action in all cases.
 
         if (!$actor_is_author && !$always_allow_close) {
           return pht(
             "You can not close this revision because you do not own it. To ".
             "close a revision, you must be its owner.");
         }
 
         if ($revision_status != $status_accepted) {
           return pht(
             "You can not close this revision because it has not been ".
             "accepted. You can only close accepted revisions.");
         }
         break;
     }
 
     return null;
   }
 
   protected function sortTransactions(array $xactions) {
     $head = array();
     $tail = array();
 
     // Move bare comments to the end, so the actions precede them.
     foreach ($xactions as $xaction) {
       $type = $xaction->getTransactionType();
       if ($type == DifferentialTransaction::TYPE_INLINE) {
         $tail[] = $xaction;
       } else {
         $head[] = $xaction;
       }
     }
 
     return array_values(array_merge($head, $tail));
   }
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
     }
 
     return parent::requireCapabilities($object, $xaction);
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     $phids = array();
     $phids[] = $object->getAuthorPHID();
     foreach ($object->getReviewerStatus() as $reviewer) {
       $phids[] = $reviewer->getReviewerPHID();
     }
     return $phids;
   }
 
   protected function getMailSubjectPrefix() {
     return PhabricatorEnv::getEnvConfig('metamta.differential.subject-prefix');
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new DifferentialReplyHandler())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $title = $object->getTitle();
 
     $original_title = $object->getOriginalTitle();
 
     $subject = "D{$id}: {$title}";
     $thread_topic = "D{$id}: {$original_title}";
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject($subject)
       ->addHeader('Thread-Topic', $thread_topic);
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = parent::buildMailBody($object, $xactions);
 
     $body->addTextSection(
       pht('REVISION DETAIL'),
       PhabricatorEnv::getProductionURI('/D'.$object->getID()));
 
     return $body;
   }
 
   protected function supportsSearch() {
     return true;
   }
 
   protected function extractFilePHIDsFromCustomTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
     }
 
     return parent::extractFilePHIDsFromCustomTransaction($object, $xaction);
   }
 
 }
diff --git a/src/applications/differential/storage/DifferentialTransaction.php b/src/applications/differential/storage/DifferentialTransaction.php
index 7e1d0a5ada..14848d01ef 100644
--- a/src/applications/differential/storage/DifferentialTransaction.php
+++ b/src/applications/differential/storage/DifferentialTransaction.php
@@ -1,162 +1,168 @@
 <?php
 
 final class DifferentialTransaction extends PhabricatorApplicationTransaction {
 
   const TYPE_INLINE = 'differential:inline';
   const TYPE_UPDATE = 'differential:update';
   const TYPE_ACTION = 'differential:action';
 
   public function getApplicationName() {
     return 'differential';
   }
 
   public function getApplicationTransactionType() {
     return DifferentialPHIDTypeRevision::TYPECONST;
   }
 
   public function getApplicationTransactionCommentObject() {
     return new DifferentialTransactionComment();
   }
 
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
     $author_handle = $this->renderHandleLink($author_phid);
 
     $old = $this->getOldValue();
     $new = $this->getNewValue();
 
     switch ($this->getTransactionType()) {
       case self::TYPE_INLINE:
         return pht(
           '%s added inline comments.',
           $author_handle);
       case self::TYPE_UPDATE:
         if ($new) {
           // TODO: Migrate to PHIDs and use handles here?
           // TODO: Link this?
           return pht(
             '%s updated this revision to Diff #%d.',
             $author_handle,
             $new);
         } else {
           return pht(
             '%s updated this revision.',
             $author_handle);
         }
       case self::TYPE_ACTION:
         return DifferentialAction::getBasicStoryText($new, $author_handle);
     }
 
     return parent::getTitle();
   }
 
   public function getIcon() {
     switch ($this->getTransactionType()) {
       case self::TYPE_INLINE:
         return 'comment';
       case self::TYPE_UPDATE:
         return 'refresh';
       case self::TYPE_ACTION:
         switch ($this->getNewValue()) {
           case DifferentialAction::ACTION_CLOSE:
             return 'ok';
           case DifferentialAction::ACTION_ACCEPT:
             return 'enable';
           case DifferentialAction::ACTION_REJECT:
           case DifferentialAction::ACTION_ABANDON:
             return 'delete';
           case DifferentialAction::ACTION_RETHINK:
             return 'disable';
           case DifferentialAction::ACTION_REQUEST:
             return 'refresh';
           case DifferentialAction::ACTION_RECLAIM:
           case DifferentialAction::ACTION_REOPEN:
             return 'new';
           case DifferentialAction::ACTION_RESIGN:
             return 'undo';
           case DifferentialAction::ACTION_CLAIM:
             return 'user';
         }
     }
 
     return parent::getIcon();
   }
 
   public function getColor() {
     switch ($this->getTransactionType()) {
       case self::TYPE_UPDATE:
         return PhabricatorTransactions::COLOR_SKY;
       case self::TYPE_ACTION:
         switch ($this->getNewValue()) {
           case DifferentialAction::ACTION_CLOSE:
             return PhabricatorTransactions::COLOR_BLUE;
           case DifferentialAction::ACTION_ACCEPT:
             return PhabricatorTransactions::COLOR_GREEN;
           case DifferentialAction::ACTION_REJECT:
             return PhabricatorTransactions::COLOR_RED;
           case DifferentialAction::ACTION_ABANDON:
             return PhabricatorTransactions::COLOR_BLACK;
           case DifferentialAction::ACTION_RETHINK:
             return PhabricatorTransactions::COLOR_RED;
           case DifferentialAction::ACTION_REQUEST:
             return PhabricatorTransactions::COLOR_SKY;
           case DifferentialAction::ACTION_RECLAIM:
             return PhabricatorTransactions::COLOR_SKY;
           case DifferentialAction::ACTION_REOPEN:
             return PhabricatorTransactions::COLOR_SKY;
           case DifferentialAction::ACTION_RESIGN:
             return PhabricatorTransactions::COLOR_ORANGE;
           case DifferentialAction::ACTION_CLAIM:
             return PhabricatorTransactions::COLOR_YELLOW;
         }
     }
 
 
     return parent::getColor();
   }
 
   public function getNoEffectDescription() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_EDGE:
         switch ($this->getMetadataValue('edge:type')) {
           case PhabricatorEdgeConfig::TYPE_DREV_HAS_REVIEWER:
             return pht(
               'The reviewers you are trying to add are already reviewing '.
               'this revision.');
         }
         break;
       case DifferentialTransaction::TYPE_ACTION:
         switch ($this->getNewValue()) {
           case DifferentialAction::ACTION_CLOSE:
             return pht('This revision is already closed.');
           case DifferentialAction::ACTION_ABANDON:
             return pht('This revision has already been abandoned.');
           case DifferentialAction::ACTION_RECLAIM:
             return pht(
               'You can not reclaim this revision because his revision is '.
               'not abandoned.');
           case DifferentialAction::ACTION_REOPEN:
             return pht(
               'You can not reopen this revision because this revision is '.
               'not closed.');
           case DifferentialAction::ACTION_RETHINK:
             return pht('This revision already requires changes.');
           case DifferentialAction::ACTION_REQUEST:
             return pht('Review is already requested for this revision.');
           case DifferentialAction::ACTION_RESIGN:
             return pht(
               'You can not resign from this revision because you are not '.
               'a reviewer.');
           case DifferentialAction::ACTION_CLAIM:
             return pht(
               'You can not commandeer this revision because you already own '.
               'it.');
+          case DifferentialAction::ACTION_ACCEPT:
+            return pht(
+              'You have already accepted this revision.');
+          case DifferentialAction::ACTION_REJECT:
+            return pht(
+              'You have already requested changes to this revision.');
         }
         break;
     }
 
     return parent::getNoEffectDescription();
   }
 
 
 }
diff --git a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
index a862dd5595..bef24bed2b 100644
--- a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
+++ b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
@@ -1,710 +1,714 @@
 <?php
 
 abstract class PhabricatorApplicationTransaction
   extends PhabricatorLiskDAO
   implements PhabricatorPolicyInterface {
 
   const TARGET_TEXT = 'text';
   const TARGET_HTML = 'html';
 
   protected $phid;
   protected $objectPHID;
   protected $authorPHID;
   protected $viewPolicy;
   protected $editPolicy;
 
   protected $commentPHID;
   protected $commentVersion = 0;
   protected $transactionType;
   protected $oldValue;
   protected $newValue;
   protected $metadata = array();
 
   protected $contentSource;
 
   private $comment;
   private $commentNotLoaded;
 
   private $handles;
   private $renderingTarget = self::TARGET_HTML;
   private $transactionGroup = array();
   private $viewer = self::ATTACHABLE;
   private $object = self::ATTACHABLE;
 
   private $ignoreOnNoEffect;
 
 
   /**
    * Flag this transaction as a pure side-effect which should be ignored when
    * applying transactions if it has no effect, even if transaction application
    * would normally fail. This both provides users with better error messages
    * and allows transactions to perform optional side effects.
    */
   public function setIgnoreOnNoEffect($ignore) {
     $this->ignoreOnNoEffect = $ignore;
     return $this;
   }
 
   public function getIgnoreOnNoEffect() {
     return $this->ignoreOnNoEffect;
   }
 
   abstract public function getApplicationTransactionType();
 
   private function getApplicationObjectTypeName() {
     $types = PhabricatorPHIDType::getAllTypes();
 
     $type = idx($types, $this->getApplicationTransactionType());
     if ($type) {
       return $type->getTypeName();
     }
 
     return pht('Object');
   }
 
   public function getApplicationTransactionCommentObject() {
     throw new Exception("Not implemented!");
   }
 
   public function getApplicationTransactionViewObject() {
     return new PhabricatorApplicationTransactionView();
   }
 
   public function getMetadataValue($key, $default = null) {
     return idx($this->metadata, $key, $default);
   }
 
   public function setMetadataValue($key, $value) {
     $this->metadata[$key] = $value;
     return $this;
   }
 
   public function generatePHID() {
     $type = PhabricatorApplicationTransactionPHIDTypeTransaction::TYPECONST;
     $subtype = $this->getApplicationTransactionType();
 
     return PhabricatorPHID::generateNewPHID($type, $subtype);
   }
 
   public function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_SERIALIZATION => array(
         'oldValue' => self::SERIALIZATION_JSON,
         'newValue' => self::SERIALIZATION_JSON,
         'metadata' => self::SERIALIZATION_JSON,
       ),
     ) + parent::getConfiguration();
   }
 
   public function setContentSource(PhabricatorContentSource $content_source) {
     $this->contentSource = $content_source->serialize();
     return $this;
   }
 
   public function getContentSource() {
     return PhabricatorContentSource::newFromSerialized($this->contentSource);
   }
 
   public function hasComment() {
     return $this->getComment() && strlen($this->getComment()->getContent());
   }
 
   public function getComment() {
     if ($this->commentNotLoaded) {
       throw new Exception("Comment for this transaction was not loaded.");
     }
     return $this->comment;
   }
 
   public function attachComment(
     PhabricatorApplicationTransactionComment $comment) {
     $this->comment = $comment;
     $this->commentNotLoaded = false;
     return $this;
   }
 
   public function setCommentNotLoaded($not_loaded) {
     $this->commentNotLoaded = $not_loaded;
     return $this;
   }
 
   public function attachObject($object) {
     $this->object = $object;
     return $this;
   }
 
   public function getObject() {
     return $this->assertAttached($this->object);
   }
 
 /* -(  Rendering  )---------------------------------------------------------- */
 
   public function setRenderingTarget($rendering_target) {
     $this->renderingTarget = $rendering_target;
     return $this;
   }
 
   public function getRenderingTarget() {
     return $this->renderingTarget;
   }
 
   public function attachViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   public function getViewer() {
     return $this->assertAttached($this->viewer);
   }
 
   public function getRequiredHandlePHIDs() {
     $phids = array();
 
     $old = $this->getOldValue();
     $new = $this->getNewValue();
 
     $phids[] = array($this->getAuthorPHID());
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getTransactionCustomField();
         if ($field) {
           $phids[] = $field->getApplicationTransactionRequiredHandlePHIDs(
             $this);
         }
         break;
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         $phids[] = $old;
         $phids[] = $new;
         break;
       case PhabricatorTransactions::TYPE_EDGE:
         $phids[] = ipull($old, 'dst');
         $phids[] = ipull($new, 'dst');
         break;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         if (!PhabricatorPolicyQuery::isGlobalPolicy($old)) {
           $phids[] = array($old);
         }
         if (!PhabricatorPolicyQuery::isGlobalPolicy($new)) {
           $phids[] = array($new);
         }
         break;
     }
 
     return array_mergev($phids);
   }
 
   public function setHandles(array $handles) {
     $this->handles = $handles;
     return $this;
   }
 
   public function getHandle($phid) {
     if (empty($this->handles[$phid])) {
       throw new Exception(
         pht(
           'Transaction ("%s") requires a handle ("%s") that it did not '.
           'load.',
           $this->getPHID(),
           $phid));
     }
     return $this->handles[$phid];
   }
 
   public function getHandleIfExists($phid) {
     return idx($this->handles, $phid);
   }
 
   public function getHandles() {
     if ($this->handles === null) {
       throw new Exception(
         'Transaction requires handles and it did not load them.'
       );
     }
     return $this->handles;
   }
 
   public function renderHandleLink($phid) {
     if ($this->renderingTarget == self::TARGET_HTML) {
       return $this->getHandle($phid)->renderLink();
     } else {
       return $this->getHandle($phid)->getLinkName();
     }
   }
 
   public function renderHandleList(array $phids) {
     $links = array();
     foreach ($phids as $phid) {
       $links[] = $this->renderHandleLink($phid);
     }
     if ($this->renderingTarget == self::TARGET_HTML) {
       return phutil_implode_html(', ', $links);
     } else {
       return implode(', ', $links);
     }
   }
 
   public function renderPolicyName($phid) {
     $policy = PhabricatorPolicy::newFromPolicyAndHandle(
       $phid,
       $this->getHandleIfExists($phid));
     if ($this->renderingTarget == self::TARGET_HTML) {
       $output = $policy->renderDescription();
     } else {
       $output = hsprintf('%s', $policy->getFullName());
     }
     return $output;
   }
 
   public function getIcon() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return 'comment';
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return 'message';
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return 'lock';
       case PhabricatorTransactions::TYPE_EDGE:
         return 'link';
     }
 
     return 'edit';
   }
 
   public function getColor() {
     return null;
   }
 
   protected function getTransactionCustomField() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $key = $this->getMetadataValue('customfield:key');
         if (!$key) {
           return null;
         }
 
         $field = PhabricatorCustomField::getObjectField(
           $this->getObject(),
           PhabricatorCustomField::ROLE_APPLICATIONTRANSACTIONS,
           $key);
         if (!$field) {
           return null;
         }
 
         $field->setViewer($this->getViewer());
         return $field;
     }
 
     return null;
   }
 
   public function shouldHide() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         if ($this->getOldValue() === null) {
           return true;
         } else {
           return false;
         }
         break;
     }
 
     return false;
   }
 
   public function shouldHideForMail() {
     return $this->shouldHide();
   }
 
   public function getNoEffectDescription() {
 
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return pht('You can not post an empty comment.');
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return pht(
           'This %s already has that view policy.',
           $this->getApplicationObjectTypeName());
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return pht(
           'This %s already has that edit policy.',
           $this->getApplicationObjectTypeName());
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return pht(
           'This %s already has that join policy.',
           $this->getApplicationObjectTypeName());
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return pht(
           'All users are already subscribed to this %s.',
           $this->getApplicationObjectTypeName());
       case PhabricatorTransactions::TYPE_EDGE:
         return pht('Edges already exist; transaction has no effect.');
     }
 
     return pht('Transaction has no effect.');
   }
 
   public function getTitle() {
     $author_phid = $this->getAuthorPHID();
 
     $old = $this->getOldValue();
     $new = $this->getNewValue();
 
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return pht(
           '%s added a comment.',
           $this->renderHandleLink($author_phid));
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return pht(
           '%s changed the visibility of this %s from "%s" to "%s".',
           $this->renderHandleLink($author_phid),
           $this->getApplicationObjectTypeName(),
           $this->renderPolicyName($old),
           $this->renderPolicyName($new));
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return pht(
           '%s changed the edit policy of this %s from "%s" to "%s".',
           $this->renderHandleLink($author_phid),
           $this->getApplicationObjectTypeName(),
           $this->renderPolicyName($old),
           $this->renderPolicyName($new));
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return pht(
           '%s changed the join policy of this %s from "%s" to "%s".',
           $this->renderHandleLink($author_phid),
           $this->getApplicationObjectTypeName(),
           $this->renderPolicyName($old),
           $this->renderPolicyName($new));
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         $add = array_diff($new, $old);
         $rem = array_diff($old, $new);
 
         if ($add && $rem) {
           return pht(
             '%s edited subscriber(s), added %d: %s; removed %d: %s.',
             $this->renderHandleLink($author_phid),
             count($add),
             $this->renderHandleList($add),
             count($rem),
             $this->renderHandleList($rem));
         } else if ($add) {
           return pht(
             '%s added %d subscriber(s): %s.',
             $this->renderHandleLink($author_phid),
             count($add),
             $this->renderHandleList($add));
         } else if ($rem) {
           return pht(
             '%s removed %d subscriber(s): %s.',
             $this->renderHandleLink($author_phid),
             count($rem),
             $this->renderHandleList($rem));
         } else {
           // This is used when rendering previews, before the user actually
           // selects any CCs.
           return pht(
             '%s updated subscribers...',
             $this->renderHandleLink($author_phid));
         }
         break;
       case PhabricatorTransactions::TYPE_EDGE:
         $new = ipull($new, 'dst');
         $old = ipull($old, 'dst');
         $add = array_diff($new, $old);
         $rem = array_diff($old, $new);
         $type = $this->getMetadata('edge:type');
         $type = head($type);
 
         if ($add && $rem) {
           $string = PhabricatorEdgeConfig::getEditStringForEdgeType($type);
           return pht(
             $string,
             $this->renderHandleLink($author_phid),
             count($add),
             $this->renderHandleList($add),
             count($rem),
             $this->renderHandleList($rem));
         } else if ($add) {
           $string = PhabricatorEdgeConfig::getAddStringForEdgeType($type);
           return pht(
             $string,
             $this->renderHandleLink($author_phid),
             count($add),
             $this->renderHandleList($add));
-        } else {
+        } else if ($rem) {
           $string = PhabricatorEdgeConfig::getRemoveStringForEdgeType($type);
           return pht(
             $string,
             $this->renderHandleLink($author_phid),
             count($rem),
             $this->renderHandleList($rem));
+        } else {
+          return pht(
+            '%s edited edge metadata.',
+            $this->renderHandleLink($author_phid));
         }
 
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getTransactionCustomField();
         if ($field) {
           return $field->getApplicationTransactionTitle($this);
         } else {
           return pht(
             '%s edited a custom field.',
             $this->renderHandleLink($author_phid));
         }
 
       default:
         return pht(
           '%s edited this %s.',
           $this->renderHandleLink($author_phid),
           $this->getApplicationObjectTypeName());
     }
   }
 
   public function getTitleForFeed(PhabricatorFeedStory $story) {
     $author_phid = $this->getAuthorPHID();
     $object_phid = $this->getObjectPHID();
 
     $old = $this->getOldValue();
     $new = $this->getNewValue();
 
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return pht(
           '%s added a comment to %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return pht(
           '%s changed the visibility for %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return pht(
           '%s changed the edit policy for %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return pht(
           '%s changed the join policy for %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return pht(
           '%s updated subscribers of %s.',
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_EDGE:
         $type = $this->getMetadata('edge:type');
         $type = head($type);
         $string = PhabricatorEdgeConfig::getFeedStringForEdgeType($type);
         return pht(
           $string,
           $this->renderHandleLink($author_phid),
           $this->renderHandleLink($object_phid));
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getTransactionCustomField();
         if ($field) {
           return $field->getApplicationTransactionTitleForFeed($this, $story);
         } else {
           return pht(
             '%s edited a custom field on %s.',
             $this->renderHandleLink($author_phid),
             $this->renderHandleLink($object_phid));
         }
 
     }
 
     return $this->getTitle();
   }
 
   public function getBodyForFeed(PhabricatorFeedStory $story) {
     $old = $this->getOldValue();
     $new = $this->getNewValue();
 
     $body = null;
 
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         $text = $this->getComment()->getContent();
         $body = phutil_escape_html_newlines(
           phutil_utf8_shorten($text, 128));
         break;
     }
     return $body;
   }
 
   public function getActionStrength() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return 0.5;
     }
     return 1.0;
   }
 
   public function isCommentTransaction() {
     if ($this->hasComment()) {
       return true;
     }
 
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return true;
     }
 
     return false;
   }
 
   public function getActionName() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return pht('Commented On');
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return pht('Changed Policy');
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return pht('Changed Subscribers');
       default:
         return pht('Updated');
     }
   }
 
   public function getMailTags() {
     return array();
   }
 
   public function hasChangeDetails() {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getTransactionCustomField();
         if ($field) {
           return $field->getApplicationTransactionHasChangeDetails($this);
         }
         break;
     }
     return false;
   }
 
   public function renderChangeDetails(PhabricatorUser $viewer) {
     switch ($this->getTransactionType()) {
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getTransactionCustomField();
         if ($field) {
           return $field->getApplicationTransactionChangeDetails($this, $viewer);
         }
         break;
     }
 
     return $this->renderTextCorpusChangeDetails();
   }
 
   public function renderTextCorpusChangeDetails(
     PhabricatorUser $viewer,
     $old,
     $new) {
 
     require_celerity_resource('differential-changeset-view-css');
 
     $view = id(new PhabricatorApplicationTransactionTextDiffDetailView())
       ->setUser($viewer)
       ->setOldText($old)
       ->setNewText($new);
 
     return $view->render();
   }
 
   public function attachTransactionGroup(array $group) {
     assert_instances_of($group, 'PhabricatorApplicationTransaction');
     $this->transactionGroup = $group;
     return $this;
   }
 
   public function getTransactionGroup() {
     return $this->transactionGroup;
   }
 
   /**
    * Should this transaction be visually grouped with an existing transaction
    * group?
    *
    * @param list<PhabricatorApplicationTransaction> List of transactions.
    * @return bool True to display in a group with the other transactions.
    */
   public function shouldDisplayGroupWith(array $group) {
     $this_source = null;
     if ($this->getContentSource()) {
       $this_source = $this->getContentSource()->getSource();
     }
 
     foreach ($group as $xaction) {
       // Don't group transactions by different authors.
       if ($xaction->getAuthorPHID() != $this->getAuthorPHID()) {
         return false;
       }
 
       // Don't group transactions for different objects.
       if ($xaction->getObjectPHID() != $this->getObjectPHID()) {
         return false;
       }
 
       // Don't group anything into a group which already has a comment.
       if ($xaction->isCommentTransaction()) {
         return false;
       }
 
       // Don't group transactions from different content sources.
       $other_source = null;
       if ($xaction->getContentSource()) {
         $other_source = $xaction->getContentSource()->getSource();
       }
 
       if ($other_source != $this_source) {
         return false;
       }
 
       // Don't group transactions which happened more than 2 minutes apart.
       $apart = abs($xaction->getDateCreated() - $this->getDateCreated());
       if ($apart > (60 * 2)) {
         return false;
       }
     }
 
     return true;
   }
 
 
 /* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
       PhabricatorPolicyCapability::CAN_EDIT,
     );
   }
 
   public function getPolicy($capability) {
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         return $this->getViewPolicy();
       case PhabricatorPolicyCapability::CAN_EDIT:
         return $this->getEditPolicy();
     }
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return ($viewer->getPHID() == $this->getAuthorPHID());
   }
 
   public function describeAutomaticCapability($capability) {
     // TODO: (T603) Exact policies are unclear here.
     return null;
   }
 
 
 }