diff --git a/src/applications/maniphest/editor/ManiphestTransactionEditor.php b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
index 2c9463f928..2ef22808e7 100644
--- a/src/applications/maniphest/editor/ManiphestTransactionEditor.php
+++ b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
@@ -1,425 +1,435 @@
 <?php
 
 final class ManiphestTransactionEditor
   extends PhabricatorApplicationTransactionEditor {
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
     $types[] = ManiphestTransaction::TYPE_PRIORITY;
     $types[] = ManiphestTransaction::TYPE_STATUS;
     $types[] = ManiphestTransaction::TYPE_TITLE;
     $types[] = ManiphestTransaction::TYPE_DESCRIPTION;
     $types[] = ManiphestTransaction::TYPE_OWNER;
     $types[] = ManiphestTransaction::TYPE_CCS;
     $types[] = ManiphestTransaction::TYPE_PROJECTS;
     $types[] = ManiphestTransaction::TYPE_ATTACH;
     $types[] = ManiphestTransaction::TYPE_EDGE;
     $types[] = ManiphestTransaction::TYPE_SUBPRIORITY;
     $types[] = ManiphestTransaction::TYPE_PROJECT_COLUMN;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PRIORITY:
         if ($this->getIsNewObject()) {
           return null;
         }
         return (int)$object->getPriority();
       case ManiphestTransaction::TYPE_STATUS:
         if ($this->getIsNewObject()) {
           return null;
         }
         return (int)$object->getStatus();
       case ManiphestTransaction::TYPE_TITLE:
         if ($this->getIsNewObject()) {
           return null;
         }
         return $object->getTitle();
       case ManiphestTransaction::TYPE_DESCRIPTION:
         if ($this->getIsNewObject()) {
           return null;
         }
         return $object->getDescription();
       case ManiphestTransaction::TYPE_OWNER:
         return nonempty($object->getOwnerPHID(), null);
       case ManiphestTransaction::TYPE_CCS:
         return array_values(array_unique($object->getCCPHIDs()));
       case ManiphestTransaction::TYPE_PROJECTS:
         return array_values(array_unique($object->getProjectPHIDs()));
       case ManiphestTransaction::TYPE_ATTACH:
         return $object->getAttached();
       case ManiphestTransaction::TYPE_EDGE:
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         // These are pre-populated.
         return $xaction->getOldValue();
       case ManiphestTransaction::TYPE_SUBPRIORITY:
         return $object->getSubpriority();
     }
 
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PRIORITY:
       case ManiphestTransaction::TYPE_STATUS:
         return (int)$xaction->getNewValue();
       case ManiphestTransaction::TYPE_CCS:
       case ManiphestTransaction::TYPE_PROJECTS:
         return array_values(array_unique($xaction->getNewValue()));
       case ManiphestTransaction::TYPE_OWNER:
         return nonempty($xaction->getNewValue(), null);
       case ManiphestTransaction::TYPE_TITLE:
       case ManiphestTransaction::TYPE_DESCRIPTION:
       case ManiphestTransaction::TYPE_ATTACH:
       case ManiphestTransaction::TYPE_EDGE:
       case ManiphestTransaction::TYPE_SUBPRIORITY:
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         return $xaction->getNewValue();
     }
   }
 
 
   protected function transactionHasEffect(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $old = $xaction->getOldValue();
     $new = $xaction->getNewValue();
 
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PROJECTS:
       case ManiphestTransaction::TYPE_CCS:
         sort($old);
         sort($new);
         return ($old !== $new);
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         $new_column_phids = $new['columnPHIDs'];
         $old_column_phids = $old['columnPHIDs'];
         sort($new_column_phids);
         sort($old_column_phids);
         return ($old !== $new);
     }
 
     return parent::transactionHasEffect($object, $xaction);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PRIORITY:
         return $object->setPriority($xaction->getNewValue());
       case ManiphestTransaction::TYPE_STATUS:
         return $object->setStatus($xaction->getNewValue());
       case ManiphestTransaction::TYPE_TITLE:
         return $object->setTitle($xaction->getNewValue());
       case ManiphestTransaction::TYPE_DESCRIPTION:
         return $object->setDescription($xaction->getNewValue());
       case ManiphestTransaction::TYPE_OWNER:
         $phid = $xaction->getNewValue();
 
         // Update the "ownerOrdering" column to contain the full name of the
         // owner, if the task is assigned.
 
         $handle = null;
         if ($phid) {
           $handle = id(new PhabricatorHandleQuery())
             ->setViewer($this->getActor())
             ->withPHIDs(array($phid))
             ->executeOne();
         }
 
         if ($handle) {
           $object->setOwnerOrdering($handle->getName());
         } else {
           $object->setOwnerOrdering(null);
         }
 
         return $object->setOwnerPHID($phid);
       case ManiphestTransaction::TYPE_CCS:
         return $object->setCCPHIDs($xaction->getNewValue());
       case ManiphestTransaction::TYPE_PROJECTS:
         return $object->setProjectPHIDs($xaction->getNewValue());
       case ManiphestTransaction::TYPE_ATTACH:
         return $object->setAttached($xaction->getNewValue());
       case ManiphestTransaction::TYPE_EDGE:
         // These are a weird, funky mess and are already being applied by the
         // time we reach this.
         return;
       case ManiphestTransaction::TYPE_SUBPRIORITY:
         $data = $xaction->getNewValue();
         $new_sub = $this->getNextSubpriority(
           $data['newPriority'],
           $data['newSubpriorityBase']);
         $object->setSubpriority($new_sub);
         return;
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         // these do external (edge) updates
         return;
     }
 
   }
 
   protected function expandTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $xactions = parent::expandTransaction($object, $xaction);
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_SUBPRIORITY:
         $data = $xaction->getNewValue();
         $new_pri = $data['newPriority'];
         if ($new_pri != $object->getPriority()) {
           $xactions[] = id(new ManiphestTransaction())
             ->setTransactionType(ManiphestTransaction::TYPE_PRIORITY)
             ->setNewValue($new_pri);
         }
         break;
       default:
         break;
     }
 
     return $xactions;
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         $new = $xaction->getNewValue();
         $old = $xaction->getOldValue();
         $src = $object->getPHID();
         $dst = head($new['columnPHIDs']);
         $edges = $old['columnPHIDs'];
         $edge_type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_COLUMN;
         // NOTE: Normally, we expect only one edge to exist, but this works in
         // a general way so it will repair any stray edges.
         $remove = array();
         $edge_missing = true;
         foreach ($edges as $phid) {
           if ($phid == $dst) {
             $edge_missing = false;
           } else {
             $remove[] = $phid;
           }
         }
 
         $add = array();
         if ($edge_missing) {
           $add[] = $dst;
         }
 
         // This should never happen because of the code in
         // transactionHasEffect, but keep it for maximum conservativeness
         if (!$add && !$remove) {
           return;
         }
 
         $editor = id(new PhabricatorEdgeEditor())
           ->setActor($this->getActor())
           ->setSuppressEvents(true);
 
         foreach ($add as $phid) {
           $editor->addEdge($src, $edge_type, $phid);
         }
         foreach ($remove as $phid) {
           $editor->removeEdge($src, $edge_type, $phid);
         }
         $editor->save();
         break;
       default:
         break;
     }
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $xactions = mfilter($xactions, 'shouldHide', true);
     return $xactions;
   }
 
   protected function getMailSubjectPrefix() {
     return PhabricatorEnv::getEnvConfig('metamta.maniphest.subject-prefix');
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
     return 'maniphest-task-'.$object->getPHID();
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     return array(
       $object->getOwnerPHID(),
       $this->requireActor()->getPHID(),
     );
   }
 
   protected function getMailCC(PhabricatorLiskDAO $object) {
     return $object->getCCPHIDs();
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new ManiphestReplyHandler())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $title = $object->getTitle();
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject("T{$id}: {$title}")
       ->addHeader('Thread-Topic', "T{$id}: ".$object->getOriginalTitle());
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = parent::buildMailBody($object, $xactions);
 
     if ($this->getIsNewObject()) {
       $body->addTextSection(
         pht('TASK DESCRIPTION'),
         $object->getDescription());
     }
 
     $body->addTextSection(
       pht('TASK DETAIL'),
       PhabricatorEnv::getProductionURI('/T'.$object->getID()));
 
     return $body;
   }
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return $this->shouldSendMail($object, $xactions);
   }
 
   protected function supportsSearch() {
     return true;
   }
 
-  protected function supportsHerald() {
+  protected function shouldApplyHeraldRules(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
     return true;
   }
 
   protected function buildHeraldAdapter(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return id(new HeraldManiphestTaskAdapter())
       ->setTask($object);
   }
 
   protected function didApplyHeraldRules(
     PhabricatorLiskDAO $object,
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
 
+    // TODO: Convert these to transactions. The way Maniphest deals with these
+    // transactions is currently unconventional and messy.
+
     $save_again = false;
     $cc_phids = $adapter->getCcPHIDs();
     if ($cc_phids) {
       $existing_cc = $object->getCCPHIDs();
       $new_cc = array_unique(array_merge($cc_phids, $existing_cc));
       $object->setCCPHIDs($new_cc);
       $save_again = true;
     }
 
-    $assign_phid = $adapter->getAssignPHID();
-    if ($assign_phid) {
-      $object->setOwnerPHID($assign_phid);
-      $save_again = true;
-    }
-
     $project_phids = $adapter->getProjectPHIDs();
     if ($project_phids) {
       $existing_projects = $object->getProjectPHIDs();
       $new_projects = array_unique(
         array_merge($project_phids, $existing_projects));
       $object->setProjectPHIDs($new_projects);
       $save_again = true;
     }
 
     if ($save_again) {
       $object->save();
     }
+
+    $xactions = array();
+
+    $assign_phid = $adapter->getAssignPHID();
+    if ($assign_phid) {
+      $xactions[] = id(new ManiphestTransaction())
+        ->setTransactionType(ManiphestTransaction::TYPE_OWNER)
+        ->setNewValue($assign_phid);
+    }
+
+    return $xactions;
   }
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     parent::requireCapabilities($object, $xaction);
 
     $app_capability_map = array(
       ManiphestTransaction::TYPE_PRIORITY =>
         ManiphestCapabilityEditPriority::CAPABILITY,
       ManiphestTransaction::TYPE_STATUS =>
         ManiphestCapabilityEditStatus::CAPABILITY,
       ManiphestTransaction::TYPE_PROJECTS =>
         ManiphestCapabilityEditProjects::CAPABILITY,
       ManiphestTransaction::TYPE_OWNER =>
         ManiphestCapabilityEditAssign::CAPABILITY,
       PhabricatorTransactions::TYPE_EDIT_POLICY =>
         ManiphestCapabilityEditPolicies::CAPABILITY,
       PhabricatorTransactions::TYPE_VIEW_POLICY =>
         ManiphestCapabilityEditPolicies::CAPABILITY,
     );
 
     $transaction_type = $xaction->getTransactionType();
     $app_capability = idx($app_capability_map, $transaction_type);
 
     if ($app_capability) {
       $app = id(new PhabricatorApplicationQuery())
         ->setViewer($this->getActor())
         ->withClasses(array('PhabricatorApplicationManiphest'))
         ->executeOne();
       PhabricatorPolicyFilter::requireCapability(
         $this->getActor(),
         $app,
         $app_capability);
     }
   }
 
 
   private function getNextSubpriority($pri, $sub) {
 
     if ($sub === null) {
       $next = id(new ManiphestTask())->loadOneWhere(
         'priority = %d ORDER BY subpriority ASC LIMIT 1',
         $pri);
       if ($next) {
         return $next->getSubpriority() - ((double)(2 << 16));
       }
     } else {
       $next = id(new ManiphestTask())->loadOneWhere(
         'priority = %d AND subpriority > %s ORDER BY subpriority ASC LIMIT 1',
         $pri,
         $sub);
       if ($next) {
         return ($sub + $next->getSubpriority()) / 2;
       }
     }
 
     return (double)(2 << 32);
   }
 
 }
diff --git a/src/applications/metamta/contentsource/PhabricatorContentSource.php b/src/applications/metamta/contentsource/PhabricatorContentSource.php
index 8c062ba880..57ebb1b75d 100644
--- a/src/applications/metamta/contentsource/PhabricatorContentSource.php
+++ b/src/applications/metamta/contentsource/PhabricatorContentSource.php
@@ -1,96 +1,98 @@
 <?php
 
 final class PhabricatorContentSource {
 
   const SOURCE_UNKNOWN  = 'unknown';
   const SOURCE_WEB      = 'web';
   const SOURCE_EMAIL    = 'email';
   const SOURCE_CONDUIT  = 'conduit';
   const SOURCE_MOBILE   = 'mobile';
   const SOURCE_TABLET   = 'tablet';
   const SOURCE_FAX      = 'fax';
   const SOURCE_CONSOLE  = 'console';
+  const SOURCE_HERALD   = 'herald';
   const SOURCE_LEGACY   = 'legacy';
 
   private $source;
   private $params = array();
 
   private function __construct() {
     // <empty>
   }
 
   public static function newForSource($source, array $params) {
     $obj = new PhabricatorContentSource();
     $obj->source = $source;
     $obj->params = $params;
 
     return $obj;
   }
 
   public static function newFromSerialized($serialized) {
     $dict = json_decode($serialized, true);
     if (!is_array($dict)) {
       $dict = array();
     }
 
     $obj = new PhabricatorContentSource();
     $obj->source = idx($dict, 'source', self::SOURCE_UNKNOWN);
     $obj->params = idx($dict, 'params', array());
 
     return $obj;
   }
 
   public static function newConsoleSource() {
     return self::newForSource(
       PhabricatorContentSource::SOURCE_CONSOLE,
       array());
   }
 
   public static function newFromRequest(AphrontRequest $request) {
     return self::newForSource(
       PhabricatorContentSource::SOURCE_WEB,
       array(
         'ip' => $request->getRemoteAddr(),
       ));
   }
 
   public static function newFromConduitRequest(ConduitAPIRequest $request) {
     return self::newForSource(
       PhabricatorContentSource::SOURCE_CONDUIT,
       array());
   }
 
   public static function getSourceNameMap() {
     return array(
       self::SOURCE_WEB      => pht('Web'),
       self::SOURCE_EMAIL    => pht('Email'),
       self::SOURCE_CONDUIT  => pht('Conduit'),
       self::SOURCE_MOBILE   => pht('Mobile'),
       self::SOURCE_TABLET   => pht('Tablet'),
       self::SOURCE_FAX      => pht('Fax'),
       self::SOURCE_CONSOLE  => pht('Console'),
       self::SOURCE_LEGACY   => pht('Legacy'),
-      self::SOURCE_UNKNOWN  => pht('Other'),
+      self::SOURCE_HERALD   => pht('Herald'),
+      self::SOURCE_UNKNOWN  => pht('Old World'),
     );
   }
 
   public function serialize() {
     return json_encode(array(
       'source' => $this->getSource(),
       'params' => $this->getParams(),
     ));
   }
 
   public function getSource() {
     return $this->source;
   }
 
   public function getParams() {
     return $this->params;
   }
 
   public function getParam($key, $default = null) {
     return idx($this->params, $key, $default);
   }
 
 }
diff --git a/src/applications/metamta/contentsource/PhabricatorContentSourceView.php b/src/applications/metamta/contentsource/PhabricatorContentSourceView.php
index f519cf98f2..6a37e3c824 100644
--- a/src/applications/metamta/contentsource/PhabricatorContentSourceView.php
+++ b/src/applications/metamta/contentsource/PhabricatorContentSourceView.php
@@ -1,40 +1,32 @@
 <?php
 
 final class PhabricatorContentSourceView extends AphrontView {
 
   private $contentSource;
 
   public function setContentSource(PhabricatorContentSource $content_source) {
     $this->contentSource = $content_source;
     return $this;
   }
 
   public function render() {
     require_celerity_resource('phabricator-content-source-view-css');
 
-    $map = array(
-      PhabricatorContentSource::SOURCE_WEB      => pht('Web'),
-      PhabricatorContentSource::SOURCE_CONDUIT  => pht('Conduit'),
-      PhabricatorContentSource::SOURCE_EMAIL    => pht('Email'),
-      PhabricatorContentSource::SOURCE_MOBILE   => pht('Mobile'),
-      PhabricatorContentSource::SOURCE_TABLET   => pht('Tablet'),
-      PhabricatorContentSource::SOURCE_FAX      => pht('Fax'),
-      PhabricatorContentSource::SOURCE_LEGACY   => pht('Old World'),
-    );
+    $map = PhabricatorContentSource::getSourceNameMap();
 
     $source = $this->contentSource->getSource();
     $type = idx($map, $source, null);
 
     if (!$type) {
       return null;
     }
 
     return phutil_tag(
       'span',
       array(
         'class' => "phabricator-content-source-view",
       ),
       "Via {$type}");
   }
 
 }
diff --git a/src/applications/pholio/editor/PholioMockEditor.php b/src/applications/pholio/editor/PholioMockEditor.php
index 25a1369bec..6b6b9c8425 100644
--- a/src/applications/pholio/editor/PholioMockEditor.php
+++ b/src/applications/pholio/editor/PholioMockEditor.php
@@ -1,471 +1,477 @@
 <?php
 
 /**
  * @group pholio
  */
 final class PholioMockEditor extends PhabricatorApplicationTransactionEditor {
 
   private $newImages = array();
   private function setNewImages(array $new_images) {
     assert_instances_of($new_images, 'PholioImage');
     $this->newImages = $new_images;
     return $this;
   }
   private function getNewImages() {
     return $this->newImages;
   }
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_EDGE;
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
 
     $types[] = PholioTransactionType::TYPE_NAME;
     $types[] = PholioTransactionType::TYPE_DESCRIPTION;
     $types[] = PholioTransactionType::TYPE_INLINE;
 
     $types[] = PholioTransactionType::TYPE_IMAGE_FILE;
     $types[] = PholioTransactionType::TYPE_IMAGE_NAME;
     $types[] = PholioTransactionType::TYPE_IMAGE_DESCRIPTION;
     $types[] = PholioTransactionType::TYPE_IMAGE_REPLACE;
     $types[] = PholioTransactionType::TYPE_IMAGE_SEQUENCE;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_NAME:
         return $object->getName();
       case PholioTransactionType::TYPE_DESCRIPTION:
         return $object->getDescription();
       case PholioTransactionType::TYPE_IMAGE_FILE:
         $images = $object->getImages();
         return mpull($images, 'getPHID');
       case PholioTransactionType::TYPE_IMAGE_NAME:
         $name = null;
         $phid = null;
         $image = $this->getImageForXaction($object, $xaction);
         if ($image) {
           $name = $image->getName();
           $phid = $image->getPHID();
         }
         return array($phid => $name);
       case PholioTransactionType::TYPE_IMAGE_DESCRIPTION:
         $description = null;
         $phid = null;
         $image = $this->getImageForXaction($object, $xaction);
         if ($image) {
           $description = $image->getDescription();
           $phid = $image->getPHID();
         }
         return array($phid => $description);
       case PholioTransactionType::TYPE_IMAGE_REPLACE:
         $raw = $xaction->getNewValue();
         return $raw->getReplacesImagePHID();
       case PholioTransactionType::TYPE_IMAGE_SEQUENCE:
         $sequence = null;
         $phid = null;
         $image = $this->getImageForXaction($object, $xaction);
         if ($image) {
           $sequence = $image->getSequence();
           $phid = $image->getPHID();
         }
         return array($phid => $sequence);
     }
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_NAME:
       case PholioTransactionType::TYPE_DESCRIPTION:
       case PholioTransactionType::TYPE_IMAGE_NAME:
       case PholioTransactionType::TYPE_IMAGE_DESCRIPTION:
       case PholioTransactionType::TYPE_IMAGE_SEQUENCE:
         return $xaction->getNewValue();
       case PholioTransactionType::TYPE_IMAGE_REPLACE:
         $raw = $xaction->getNewValue();
         return $raw->getPHID();
       case PholioTransactionType::TYPE_IMAGE_FILE:
         $raw_new_value = $xaction->getNewValue();
         $new_value = array();
         foreach ($raw_new_value as $key => $images) {
           $new_value[$key] = mpull($images, 'getPHID');
         }
         $xaction->setNewValue($new_value);
         return $this->getPHIDTransactionNewValue($xaction);
     }
   }
 
   protected function extractFilePHIDsFromCustomTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_IMAGE_FILE:
         $new = $xaction->getNewValue();
         $phids = array();
         foreach ($new as $key => $images) {
           $phids[] = mpull($images, 'getFilePHID');
         }
         return array_mergev($phids);
       case PholioTransactionType::TYPE_IMAGE_REPLACE:
         return array($xaction->getNewValue()->getFilePHID());
     }
 
     return array();
   }
 
 
   protected function transactionHasEffect(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_INLINE:
         return true;
     }
 
     return parent::transactionHasEffect($object, $xaction);
   }
 
   protected function shouldApplyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case PholioTransactionType::TYPE_IMAGE_FILE:
         case PholioTransactionType::TYPE_IMAGE_REPLACE:
           return true;
           break;
       }
     }
     return false;
   }
 
   protected function applyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $new_images = array();
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case PholioTransactionType::TYPE_IMAGE_FILE:
           $new_value = $xaction->getNewValue();
           foreach ($new_value as $key => $txn_images) {
             if ($key != '+') {
               continue;
             }
             foreach ($txn_images as $image) {
               $image->save();
               $new_images[] = $image;
             }
           }
           break;
         case PholioTransactionType::TYPE_IMAGE_REPLACE:
           $image = $xaction->getNewValue();
           $image->save();
           $new_images[] = $image;
           break;
       }
     }
     $this->setNewImages($new_images);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_NAME:
         $object->setName($xaction->getNewValue());
         if ($object->getOriginalName() === null) {
           $object->setOriginalName($xaction->getNewValue());
         }
         break;
       case PholioTransactionType::TYPE_DESCRIPTION:
         $object->setDescription($xaction->getNewValue());
         break;
     }
   }
 
   private function getImageForXaction(
     PholioMock $mock,
     PhabricatorApplicationTransaction $xaction) {
     $raw_new_value = $xaction->getNewValue();
     $image_phid = key($raw_new_value);
     $images = $mock->getImages();
     foreach ($images as $image) {
       if ($image->getPHID() == $image_phid) {
         return $image;
       }
     }
     return null;
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_IMAGE_FILE:
         $old_map = array_fuse($xaction->getOldValue());
         $new_map = array_fuse($xaction->getNewValue());
 
         $obsolete_map = array_diff_key($old_map, $new_map);
         $images = $object->getImages();
         foreach ($images as $seq => $image) {
           if (isset($obsolete_map[$image->getPHID()])) {
             $image->setIsObsolete(1);
             $image->save();
             unset($images[$seq]);
           }
         }
         $object->attachImages($images);
         break;
       case PholioTransactionType::TYPE_IMAGE_REPLACE:
         $old = $xaction->getOldValue();
         $images = $object->getImages();
         foreach ($images as $seq => $image) {
           if ($image->getPHID() == $old) {
             $image->setIsObsolete(1);
             $image->save();
             unset($images[$seq]);
           }
         }
         $object->attachImages($images);
         break;
       case PholioTransactionType::TYPE_IMAGE_NAME:
         $image = $this->getImageForXaction($object, $xaction);
         $value = (string) head($xaction->getNewValue());
         $image->setName($value);
         $image->save();
         break;
       case PholioTransactionType::TYPE_IMAGE_DESCRIPTION:
         $image = $this->getImageForXaction($object, $xaction);
         $value = (string) head($xaction->getNewValue());
         $image->setDescription($value);
         $image->save();
         break;
       case PholioTransactionType::TYPE_IMAGE_SEQUENCE:
         $image = $this->getImageForXaction($object, $xaction);
         $value = (int) head($xaction->getNewValue());
         $image->setSequence($value);
         $image->save();
         break;
     }
   }
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $images = $this->getNewImages();
     foreach ($images as $image) {
       $image->setMockID($object->getID());
       $image->save();
     }
 
     return $xactions;
   }
 
   protected function mergeTransactions(
     PhabricatorApplicationTransaction $u,
     PhabricatorApplicationTransaction $v) {
 
     $type = $u->getTransactionType();
     switch ($type) {
       case PholioTransactionType::TYPE_NAME:
       case PholioTransactionType::TYPE_DESCRIPTION:
         return $v;
       case PholioTransactionType::TYPE_IMAGE_REPLACE:
         $u_img = $u->getNewValue();
         $v_img = $v->getNewValue();
         if ($u_img->getReplacesImagePHID() == $v_img->getReplacesImagePHID()) {
           return $v;
         }
         break;
       case PholioTransactionType::TYPE_IMAGE_FILE:
         return $this->mergePHIDOrEdgeTransactions($u, $v);
       case PholioTransactionType::TYPE_IMAGE_NAME:
       case PholioTransactionType::TYPE_IMAGE_DESCRIPTION:
       case PholioTransactionType::TYPE_IMAGE_SEQUENCE:
         $raw_new_value_u = $u->getNewValue();
         $raw_new_value_v = $v->getNewValue();
         $phid_u = key($raw_new_value_u);
         $phid_v = key($raw_new_value_v);
         if ($phid_u == $phid_v) {
           return $v;
         }
         break;
     }
 
     return parent::mergeTransactions($u, $v);
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new PholioReplyHandler())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $name = $object->getName();
     $original_name = $object->getOriginalName();
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject("M{$id}: {$name}")
       ->addHeader('Thread-Topic', "M{$id}: {$original_name}");
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     return array(
       $object->getAuthorPHID(),
       $this->requireActor()->getPHID(),
     );
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = new PhabricatorMetaMTAMailBody();
     $headers = array();
     $comments = array();
     $inline_comments = array();
 
     foreach ($xactions as $xaction) {
       if ($xaction->shouldHide()) {
         continue;
       }
       $comment = $xaction->getComment();
       switch ($xaction->getTransactionType()) {
         case PholioTransactionType::TYPE_INLINE:
           if ($comment && strlen($comment->getContent())) {
             $inline_comments[] = $comment;
           }
           break;
         case PhabricatorTransactions::TYPE_COMMENT:
           if ($comment && strlen($comment->getContent())) {
             $comments[] = $comment->getContent();
           }
         // fallthrough
         default:
           $headers[] = id(clone $xaction)
             ->setRenderingTarget('text')
             ->getTitle();
           break;
       }
     }
 
     $body->addRawSection(implode("\n", $headers));
 
     foreach ($comments as $comment) {
       $body->addRawSection($comment);
     }
 
     if ($inline_comments) {
       $body->addRawSection(pht('INLINE COMMENTS'));
       foreach ($inline_comments as $comment) {
         $text = pht(
           'Image %d: %s',
           $comment->getImageID(),
           $comment->getContent());
         $body->addRawSection($text);
       }
     }
 
     $body->addTextSection(
       pht('MOCK DETAIL'),
       PhabricatorEnv::getProductionURI('/M'.$object->getID()));
 
     return $body;
   }
 
   protected function getMailSubjectPrefix() {
     return PhabricatorEnv::getEnvConfig('metamta.pholio.subject-prefix');
   }
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function supportsSearch() {
     return true;
   }
 
-  protected function supportsHerald() {
+  protected function shouldApplyHeraldRules(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
     return true;
   }
 
   protected function buildHeraldAdapter(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return id(new HeraldPholioMockAdapter())
       ->setMock($object);
   }
 
   protected function didApplyHeraldRules(
     PhabricatorLiskDAO $object,
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
 
+    // TODO: Convert this to be transaction-based.
+
     $cc_phids = $adapter->getCcPHIDs();
     if ($cc_phids) {
       id(new PhabricatorSubscriptionsEditor())
         ->setObject($object)
         ->setActor($this->requireActor())
         ->subscribeImplicit($cc_phids)
         ->save();
     }
+
+    return array();
   }
 
   protected function sortTransactions(array $xactions) {
     $head = array();
     $tail = array();
 
     // Move inline comments to the end, so the comments precede them.
     foreach ($xactions as $xaction) {
       $type = $xaction->getTransactionType();
       if ($type == PholioTransactionType::TYPE_INLINE) {
         $tail[] = $xaction;
       } else {
         $head[] = $xaction;
       }
     }
 
     return array_values(array_merge($head, $tail));
   }
 
   protected function shouldImplyCC(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PholioTransactionType::TYPE_INLINE:
         return true;
     }
 
     return parent::shouldImplyCC($object, $xaction);
   }
 
 }
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
index 36d1e35009..12da96f964 100644
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -1,1970 +1,2053 @@
 <?php
 
 /**
  * @task mail   Sending Mail
  * @task feed   Publishing Feed Stories
  * @task search Search Index
  * @task files  Integration with Files
  */
 abstract class PhabricatorApplicationTransactionEditor
   extends PhabricatorEditor {
 
   private $contentSource;
   private $object;
   private $xactions;
 
   private $isNewObject;
   private $mentionedPHIDs;
   private $continueOnNoEffect;
   private $continueOnMissingFields;
   private $parentMessageID;
   private $heraldAdapter;
   private $heraldTranscript;
   private $subscribers;
 
   private $isPreview;
+  private $isHeraldEditor;
+  private $actingAsPHID;
+
+  public function setActingAsPHID($acting_as_phid) {
+    $this->actingAsPHID = $acting_as_phid;
+    return $this;
+  }
+
+  public function getActingAsPHID() {
+    if ($this->actingAsPHID) {
+      return $this->actingAsPHID;
+    }
+    return $this->getActor()->getPHID();
+  }
 
   /**
    * When the editor tries to apply transactions that have no effect, should
    * it raise an exception (default) or drop them and continue?
    *
    * Generally, you will set this flag for edits coming from "Edit" interfaces,
    * and leave it cleared for edits coming from "Comment" interfaces, so the
    * user will get a useful error if they try to submit a comment that does
    * nothing (e.g., empty comment with a status change that has already been
    * performed by another user).
    *
    * @param bool  True to drop transactions without effect and continue.
    * @return this
    */
   public function setContinueOnNoEffect($continue) {
     $this->continueOnNoEffect = $continue;
     return $this;
   }
 
   public function getContinueOnNoEffect() {
     return $this->continueOnNoEffect;
   }
 
 
   /**
    * When the editor tries to apply transactions which don't populate all of
    * an object's required fields, should it raise an exception (default) or
    * drop them and continue?
    *
    * For example, if a user adds a new required custom field (like "Severity")
    * to a task, all existing tasks won't have it populated. When users
    * manually edit existing tasks, it's usually desirable to have them provide
    * a severity. However, other operations (like batch editing just the
    * owner of a task) will fail by default.
    *
    * By setting this flag for edit operations which apply to specific fields
    * (like the priority, batch, and merge editors in Maniphest), these
    * operations can continue to function even if an object is outdated.
    *
    * @param bool  True to continue when transactions don't completely satisfy
    *              all required fields.
    * @return this
    */
   public function setContinueOnMissingFields($continue_on_missing_fields) {
     $this->continueOnMissingFields = $continue_on_missing_fields;
     return $this;
   }
 
   public function getContinueOnMissingFields() {
     return $this->continueOnMissingFields;
   }
 
 
   /**
    * Not strictly necessary, but reply handlers ideally set this value to
    * make email threading work better.
    */
   public function setParentMessageID($parent_message_id) {
     $this->parentMessageID = $parent_message_id;
     return $this;
   }
   public function getParentMessageID() {
     return $this->parentMessageID;
   }
 
   protected function getIsNewObject() {
     return $this->isNewObject;
   }
 
   protected function getMentionedPHIDs() {
     return $this->mentionedPHIDs;
   }
 
   public function setIsPreview($is_preview) {
     $this->isPreview = $is_preview;
     return $this;
   }
 
   public function getIsPreview() {
     return $this->isPreview;
   }
 
+  public function setIsHeraldEditor($is_herald_editor) {
+    $this->isHeraldEditor = $is_herald_editor;
+    return $this;
+  }
+
+  public function getIsHeraldEditor() {
+    return $this->isHeraldEditor;
+  }
+
   public function getTransactionTypes() {
     $types = array();
 
     if ($this->object instanceof PhabricatorSubscribableInterface) {
       $types[] = PhabricatorTransactions::TYPE_SUBSCRIBERS;
     }
 
     if ($this->object instanceof PhabricatorCustomFieldInterface) {
       $types[] = PhabricatorTransactions::TYPE_CUSTOMFIELD;
     }
 
     return $types;
   }
 
   private function adjustTransactionValues(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     if ($xaction->shouldGenerateOldValue()) {
       $old = $this->getTransactionOldValue($object, $xaction);
       $xaction->setOldValue($old);
     }
 
     $new = $this->getTransactionNewValue($object, $xaction);
     $xaction->setNewValue($new);
   }
 
   private function getTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return array_values($this->subscribers);
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         return $object->getViewPolicy();
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return $object->getEditPolicy();
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return $object->getJoinPolicy();
       case PhabricatorTransactions::TYPE_EDGE:
         $edge_type = $xaction->getMetadataValue('edge:type');
         if (!$edge_type) {
           throw new Exception("Edge transaction has no 'edge:type'!");
         }
 
         $old_edges = array();
         if ($object->getPHID()) {
           $edge_src = $object->getPHID();
 
           $old_edges = id(new PhabricatorEdgeQuery())
             ->withSourcePHIDs(array($edge_src))
             ->withEdgeTypes(array($edge_type))
             ->needEdgeData(true)
             ->execute();
 
           $old_edges = $old_edges[$edge_src][$edge_type];
         }
         return $old_edges;
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         // NOTE: Custom fields have their old value pre-populated when they are
         // built by PhabricatorCustomFieldList.
         return $xaction->getOldValue();
       case PhabricatorTransactions::TYPE_COMMENT:
         return null;
       default:
         return $this->getCustomTransactionOldValue($object, $xaction);
     }
   }
 
   private function getTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return $this->getPHIDTransactionNewValue($xaction);
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         return $xaction->getNewValue();
       case PhabricatorTransactions::TYPE_EDGE:
         return $this->getEdgeTransactionNewValue($xaction);
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getCustomFieldForTransaction($object, $xaction);
         return $field->getNewValueFromApplicationTransactions($xaction);
       case PhabricatorTransactions::TYPE_COMMENT:
         return null;
       default:
         return $this->getCustomTransactionNewValue($object, $xaction);
     }
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     throw new Exception("Capability not supported!");
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     throw new Exception("Capability not supported!");
   }
 
   protected function transactionHasEffect(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         return $xaction->hasComment();
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getCustomFieldForTransaction($object, $xaction);
         return $field->getApplicationTransactionHasEffect($xaction);
       case PhabricatorTransactions::TYPE_EDGE:
         // A straight value comparison here doesn't always get the right
         // result, because newly added edges aren't fully populated. Instead,
         // compare the changes in a more granular way.
         $old = $xaction->getOldValue();
         $new = $xaction->getNewValue();
 
         $old_dst = array_keys($old);
         $new_dst = array_keys($new);
 
         // NOTE: For now, we don't consider edge reordering to be a change.
         // We have very few order-dependent edges and effectively no order
         // oriented UI. This might change in the future.
         sort($old_dst);
         sort($new_dst);
 
         if ($old_dst !== $new_dst) {
           // We've added or removed edges, so this transaction definitely
           // has an effect.
           return true;
         }
 
         // We haven't added or removed edges, but we might have changed
         // edge data.
         foreach ($old as $key => $old_value) {
           $new_value = $new[$key];
           if ($old_value['data'] !== $new_value['data']) {
             return true;
           }
         }
 
         return false;
     }
 
     return ($xaction->getOldValue() !== $xaction->getNewValue());
   }
 
   protected function shouldApplyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
   protected function applyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
     throw new Exception('Not implemented.');
   }
 
   private function applyInternalEffects(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         $object->setViewPolicy($xaction->getNewValue());
         break;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $object->setEditPolicy($xaction->getNewValue());
         break;
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getCustomFieldForTransaction($object, $xaction);
         return $field->applyApplicationTransactionInternalEffects($xaction);
     }
     return $this->applyCustomInternalTransaction($object, $xaction);
   }
 
   private function applyExternalEffects(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         $subeditor = id(new PhabricatorSubscriptionsEditor())
           ->setObject($object)
           ->setActor($this->requireActor());
 
         $old_map = array_fuse($xaction->getOldValue());
         $new_map = array_fuse($xaction->getNewValue());
 
         $subeditor->unsubscribe(
           array_keys(
             array_diff_key($old_map, $new_map)));
 
         $subeditor->subscribeExplicit(
           array_keys(
             array_diff_key($new_map, $old_map)));
 
         $subeditor->save();
 
         // for the rest of these edits, subscribers should include those just
         // added as well as those just removed.
         $subscribers = array_unique(array_merge(
           $this->subscribers,
           $xaction->getOldValue(),
           $xaction->getNewValue()));
         $this->subscribers = $subscribers;
 
         break;
       case PhabricatorTransactions::TYPE_EDGE:
         $old = $xaction->getOldValue();
         $new = $xaction->getNewValue();
         $src = $object->getPHID();
         $type = $xaction->getMetadataValue('edge:type');
 
         foreach ($new as $dst_phid => $edge) {
           $new[$dst_phid]['src'] = $src;
         }
 
         $editor = id(new PhabricatorEdgeEditor())
           ->setActor($this->getActor());
 
         foreach ($old as $dst_phid => $edge) {
           if (!empty($new[$dst_phid])) {
             if ($old[$dst_phid]['data'] === $new[$dst_phid]['data']) {
               continue;
             }
           }
           $editor->removeEdge($src, $type, $dst_phid);
         }
 
         foreach ($new as $dst_phid => $edge) {
           if (!empty($old[$dst_phid])) {
             if ($old[$dst_phid]['data'] === $new[$dst_phid]['data']) {
               continue;
             }
           }
 
           $data = array(
             'data' => $edge['data'],
           );
 
           $editor->addEdge($src, $type, $dst_phid, $data);
         }
 
         $editor->save();
         break;
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $field = $this->getCustomFieldForTransaction($object, $xaction);
         return $field->applyApplicationTransactionExternalEffects($xaction);
     }
 
     return $this->applyCustomExternalTransaction($object, $xaction);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     $type = $xaction->getTransactionType();
     throw new Exception(
       "Transaction type '{$type}' is missing an internal apply ".
       "implementation!");
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     $type = $xaction->getTransactionType();
     throw new Exception(
       "Transaction type '{$type}' is missing an external apply ".
       "implementation!");
   }
 
   /**
    * Fill in a transaction's common values, like author and content source.
    */
   protected function populateTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $actor = $this->getActor();
 
     // TODO: This needs to be more sophisticated once we have meta-policies.
     $xaction->setViewPolicy(PhabricatorPolicies::POLICY_PUBLIC);
-    $xaction->setEditPolicy($actor->getPHID());
 
-    $xaction->setAuthorPHID($actor->getPHID());
+    if ($actor->isOmnipotent()) {
+      $xaction->setEditPolicy(PhabricatorPolicies::POLICY_NOONE);
+    } else {
+      $xaction->setEditPolicy($actor->getPHID());
+    }
+
+    $xaction->setAuthorPHID($this->getActingAsPHID());
     $xaction->setContentSource($this->getContentSource());
     $xaction->attachViewer($actor);
     $xaction->attachObject($object);
 
     if ($object->getPHID()) {
       $xaction->setObjectPHID($object->getPHID());
     }
 
     return $xaction;
   }
 
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return $xactions;
   }
 
   public function setContentSource(PhabricatorContentSource $content_source) {
     $this->contentSource = $content_source;
     return $this;
   }
 
   public function setContentSourceFromRequest(AphrontRequest $request) {
     return $this->setContentSource(
       PhabricatorContentSource::newFromRequest($request));
   }
 
   public function getContentSource() {
     return $this->contentSource;
   }
 
   final public function applyTransactions(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $this->object = $object;
     $this->xactions = $xactions;
     $this->isNewObject = ($object->getPHID() === null);
 
     $this->validateEditParameters($object, $xactions);
 
     $actor = $this->requireActor();
 
     // NOTE: Some transaction expansion requires that the edited object be
     // attached.
     foreach ($xactions as $xaction) {
       $xaction->attachObject($object);
       $xaction->attachViewer($actor);
     }
 
     $xactions = $this->expandTransactions($object, $xactions);
     $xactions = $this->expandSupportTransactions($object, $xactions);
     $xactions = $this->combineTransactions($xactions);
 
     foreach ($xactions as $xaction) {
       $xaction = $this->populateTransaction($object, $xaction);
     }
 
     $is_preview = $this->getIsPreview();
     $read_locking = false;
     $transaction_open = false;
 
     if (!$is_preview) {
       $errors = array();
       $type_map = mgroup($xactions, 'getTransactionType');
       foreach ($this->getTransactionTypes() as $type) {
         $type_xactions = idx($type_map, $type, array());
         $errors[] = $this->validateTransaction($object, $type, $type_xactions);
       }
 
       $errors = array_mergev($errors);
 
       $continue_on_missing = $this->getContinueOnMissingFields();
       foreach ($errors as $key => $error) {
         if ($continue_on_missing && $error->getIsMissingFieldError()) {
           unset($errors[$key]);
         }
       }
 
       if ($errors) {
         throw new PhabricatorApplicationTransactionValidationException($errors);
       }
 
       $file_phids = $this->extractFilePHIDs($object, $xactions);
 
       if ($object->getID()) {
         foreach ($xactions as $xaction) {
 
           // If any of the transactions require a read lock, hold one and
           // reload the object. We need to do this fairly early so that the
           // call to `adjustTransactionValues()` (which populates old values)
           // is based on the synchronized state of the object, which may differ
           // from the state when it was originally loaded.
 
           if ($this->shouldReadLock($object, $xaction)) {
             $object->openTransaction();
             $object->beginReadLocking();
             $transaction_open = true;
             $read_locking = true;
             $object->reload();
             break;
           }
         }
       }
 
       if ($this->shouldApplyInitialEffects($object, $xactions)) {
         if (!$transaction_open) {
           $object->openTransaction();
           $transaction_open = true;
         }
       }
     }
 
     if ($this->shouldApplyInitialEffects($object, $xactions)) {
       $this->applyInitialEffects($object, $xactions);
     }
 
     foreach ($xactions as $xaction) {
       $this->adjustTransactionValues($object, $xaction);
     }
 
     $xactions = $this->filterTransactions($object, $xactions);
 
     if (!$xactions) {
       if ($read_locking) {
         $object->endReadLocking();
         $read_locking = false;
       }
       if ($transaction_open) {
         $object->killTransaction();
         $transaction_open = false;
       }
       return array();
     }
 
     // Now that we've merged, filtered, and combined transactions, check for
     // required capabilities.
     foreach ($xactions as $xaction) {
       $this->requireCapabilities($object, $xaction);
     }
 
     $xactions = $this->sortTransactions($xactions);
 
     if ($is_preview) {
       $this->loadHandles($xactions);
       return $xactions;
     }
 
     $comment_editor = id(new PhabricatorApplicationTransactionCommentEditor())
       ->setActor($actor)
       ->setContentSource($this->getContentSource());
 
     if (!$transaction_open) {
       $object->openTransaction();
     }
 
       foreach ($xactions as $xaction) {
         $this->applyInternalEffects($object, $xaction);
       }
 
       $object->save();
 
       foreach ($xactions as $xaction) {
         $xaction->setObjectPHID($object->getPHID());
         if ($xaction->getComment()) {
           $xaction->setPHID($xaction->generatePHID());
           $comment_editor->applyEdit($xaction, $xaction->getComment());
         } else {
           $xaction->save();
         }
       }
 
       if ($file_phids) {
         $this->attachFiles($object, $file_phids);
       }
 
       foreach ($xactions as $xaction) {
         $this->applyExternalEffects($object, $xaction);
       }
 
-      if ($this->supportsHerald()) {
-        $this->applyHeraldRules($object, $xactions);
-      }
-
       $xactions = $this->applyFinalEffects($object, $xactions);
 
       if ($read_locking) {
         $object->endReadLocking();
         $read_locking = false;
       }
 
     $object->saveTransaction();
 
+    // Now that we've completely applied the core transaction set, try to apply
+    // Herald rules. Herald rules are allowed to either take direct actions on
+    // the database (like writing flags), or take indirect actions (like saving
+    // some targets for CC when we generate mail a little later), or return
+    // transactions which we'll apply normally using another Editor.
+
+    // First, check if *this* is a sub-editor which is itself applying Herald
+    // rules: if it is, stop working and return so we don't descend into
+    // madness.
+
+    // Otherwise, we're not a Herald editor, so process Herald rules (possibly
+    // using a Herald editor to apply resulting transactions) and then send out
+    // mail, notifications, and feed updates about everything.
+
+    if ($this->getIsHeraldEditor()) {
+      // We are the Herald editor, so stop work here and return the updated
+      // transactions.
+      return $xactions;
+    } else if ($this->shouldApplyHeraldRules($object, $xactions)) {
+      // We are not the Herald editor, so try to apply Herald rules.
+      $herald_xactions = $this->applyHeraldRules($object, $xactions);
+
+      if ($herald_xactions) {
+        // NOTE: We're acting as the omnipotent user because rules deal with
+        // their own policy issues. We use a synthetic author PHID (the
+        // Herald application) as the author of record, so that transactions
+        // will render in a reasonable way ("Herald assigned this task ...").
+        $herald_actor = PhabricatorUser::getOmnipotentUser();
+        $herald_phid = id(new PhabricatorApplicationHerald())->getPHID();
+
+        // TODO: It would be nice to give transactions a more specific source
+        // which points at the rule which generated them. You can figure this
+        // out from transcripts, but it would be cleaner if you didn't have to.
+
+        $herald_source = PhabricatorContentSource::newForSource(
+          PhabricatorContentSource::SOURCE_HERALD,
+          array());
+
+        $herald_editor = newv(get_class($this), array())
+          ->setContinueOnNoEffect(true)
+          ->setContinueOnMissingFields(true)
+          ->setParentMessageID($this->getParentMessageID())
+          ->setIsHeraldEditor(true)
+          ->setActor($herald_actor)
+          ->setActingAsPHID($herald_phid)
+          ->setContentSource($herald_source);
+
+        $herald_xactions = $herald_editor->applyTransactions(
+          $object,
+          $herald_xactions);
+
+        // Merge the new transactions into the transaction list: we want to
+        // send email and publish feed stories about them, too.
+        $xactions = array_merge($xactions, $herald_xactions);
+      }
+    }
+
     $this->loadHandles($xactions);
 
     $mail = null;
     if ($this->shouldSendMail($object, $xactions)) {
       $mail = $this->sendMail($object, $xactions);
     }
 
     if ($this->supportsSearch()) {
       id(new PhabricatorSearchIndexer())
         ->queueDocumentForIndexing($object->getPHID());
     }
 
     if ($this->shouldPublishFeedStory($object, $xactions)) {
       $mailed = array();
       if ($mail) {
         $mailed = $mail->buildRecipientList();
       }
       $this->publishFeedStory(
         $object,
         $xactions,
         $mailed);
     }
 
     $this->didApplyTransactions($xactions);
 
     if ($object instanceof PhabricatorCustomFieldInterface) {
       // Maybe this makes more sense to move into the search index itself? For
       // now I'm putting it here since I think we might end up with things that
       // need it to be up to date once the next page loads, but if we don't go
       // there we we could move it into search once search moves to the daemons.
 
       // It now happens in the search indexer as well, but the search indexer is
       // always daemonized, so the logic above still potentially holds. We could
       // possibly get rid of this. The major motivation for putting it in the
       // indexer was to enable reindexing to work.
 
       $fields = PhabricatorCustomField::getObjectFields(
         $object,
         PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
       $fields->readFieldsFromStorage($object);
       $fields->rebuildIndexes($object);
     }
 
     return $xactions;
   }
 
   protected function didApplyTransactions(array $xactions) {
     // Hook for subclasses.
     return;
   }
 
 
   /**
    * Determine if the editor should hold a read lock on the object while
    * applying a transaction.
    *
    * If the editor does not hold a lock, two editors may read an object at the
    * same time, then apply their changes without any synchronization. For most
    * transactions, this does not matter much. However, it is important for some
    * transactions. For example, if an object has a transaction count on it, both
    * editors may read the object with `count = 23`, then independently update it
    * and save the object with `count = 24` twice. This will produce the wrong
    * state: the object really has 25 transactions, but the count is only 24.
    *
    * Generally, transactions fall into one of four buckets:
    *
    *   - Append operations: Actions like adding a comment to an object purely
    *     add information to its state, and do not depend on the current object
    *     state in any way. These transactions never need to hold locks.
    *   - Overwrite operations: Actions like changing the title or description
    *     of an object replace the current value with a new value, so the end
    *     state is consistent without a lock. We currently do not lock these
    *     transactions, although we may in the future.
    *   - Edge operations: Edge and subscription operations have internal
    *     synchronization which limits the damage race conditions can cause.
    *     We do not currently lock these transactions, although we may in the
    *     future.
    *   - Update operations: Actions like incrementing a count on an object.
    *     These operations generally should use locks, unless it is not
    *     important that the state remain consistent in the presence of races.
    *
    * @param   PhabricatorLiskDAO  Object being updated.
    * @param   PhabricatorApplicationTransaction Transaction being applied.
    * @return  bool                True to synchronize the edit with a lock.
    */
   protected function shouldReadLock(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     return false;
   }
 
   private function loadHandles(array $xactions) {
     $phids = array();
     foreach ($xactions as $key => $xaction) {
       $phids[$key] = $xaction->getRequiredHandlePHIDs();
     }
     $handles = array();
     $merged = array_mergev($phids);
     if ($merged) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($this->requireActor())
         ->withPHIDs($merged)
         ->execute();
     }
     foreach ($xactions as $key => $xaction) {
       $xaction->setHandles(array_select_keys($handles, $phids[$key]));
     }
   }
 
   private function loadSubscribers(PhabricatorLiskDAO $object) {
     if ($object->getPHID() &&
         ($object instanceof PhabricatorSubscribableInterface)) {
       $subs = PhabricatorSubscribersQuery::loadSubscribersForPHID(
         $object->getPHID());
       $this->subscribers = array_fuse($subs);
     } else {
       $this->subscribers = array();
     }
   }
 
   private function validateEditParameters(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     if (!$this->getContentSource()) {
       throw new Exception(
         "Call setContentSource() before applyTransactions()!");
     }
 
     // Do a bunch of sanity checks that the incoming transactions are fresh.
     // They should be unsaved and have only "transactionType" and "newValue"
     // set.
 
     $types = array_fill_keys($this->getTransactionTypes(), true);
 
     assert_instances_of($xactions, 'PhabricatorApplicationTransaction');
     foreach ($xactions as $xaction) {
       if ($xaction->getPHID() || $xaction->getID()) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             "You can not apply transactions which already have IDs/PHIDs!"));
       }
       if ($xaction->getObjectPHID()) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             "You can not apply transactions which already have objectPHIDs!"));
       }
       if ($xaction->getAuthorPHID()) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'You can not apply transactions which already have authorPHIDs!'));
       }
       if ($xaction->getCommentPHID()) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'You can not apply transactions which already have '.
             'commentPHIDs!'));
       }
       if ($xaction->getCommentVersion() !== 0) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'You can not apply transactions which already have '.
             'commentVersions!'));
       }
 
       $expect_value = !$xaction->shouldGenerateOldValue();
       $has_value = $xaction->hasOldValue();
 
       if ($expect_value && !$has_value) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'This transaction is supposed to have an oldValue set, but '.
             'it does not!'));
       }
 
       if ($has_value && !$expect_value) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'This transaction should generate its oldValue automatically, '.
             'but has already had one set!'));
       }
 
       $type = $xaction->getTransactionType();
       if (empty($types[$type])) {
         throw new PhabricatorApplicationTransactionStructureException(
           $xaction,
           pht(
             'Transaction has type "%s", but that transaction type is not '.
             'supported by this editor (%s).',
             $type,
             get_class($this)));
       }
     }
 
     // The actor must have permission to view and edit the object.
 
     $actor = $this->requireActor();
 
     PhabricatorPolicyFilter::requireCapability(
       $actor,
       $object,
       PhabricatorPolicyCapability::CAN_VIEW);
   }
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         // You must have the edit capability to alter the edit policy of an
         // object. For other default transaction types, we don't enforce
         // anything for the moment.
 
         PhabricatorPolicyFilter::requireCapability(
           $this->requireActor(),
           $object,
           PhabricatorPolicyCapability::CAN_EDIT);
         break;
     }
   }
 
   private function buildMentionTransaction(
     PhabricatorLiskDAO $object,
     array $xactions,
     array $blocks) {
 
     if (!($object instanceof PhabricatorSubscribableInterface)) {
       return null;
     }
 
     $texts = array_mergev($blocks);
     $phids = PhabricatorMarkupEngine::extractPHIDsFromMentions($texts);
 
     $this->mentionedPHIDs = $phids;
 
     if ($object->getPHID()) {
       // Don't try to subscribe already-subscribed mentions: we want to generate
       // a dialog about an action having no effect if the user explicitly adds
       // existing CCs, but not if they merely mention existing subscribers.
       $phids = array_diff($phids, $this->subscribers);
     }
 
     foreach ($phids as $key => $phid) {
       if ($object->isAutomaticallySubscribed($phid)) {
         unset($phids[$key]);
       }
     }
     $phids = array_values($phids);
 
     if (!$phids) {
       return null;
     }
 
     $xaction = newv(get_class(head($xactions)), array());
     $xaction->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS);
     $xaction->setNewValue(array('+' => $phids));
 
     return $xaction;
   }
 
   protected function getRemarkupBlocksFromTransaction(
     PhabricatorApplicationTransaction $transaction) {
     return $transaction->getRemarkupBlocks();
   }
 
   protected function mergeTransactions(
     PhabricatorApplicationTransaction $u,
     PhabricatorApplicationTransaction $v) {
 
     $type = $u->getTransactionType();
 
     switch ($type) {
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         return $this->mergePHIDOrEdgeTransactions($u, $v);
       case PhabricatorTransactions::TYPE_EDGE:
         $u_type = $u->getMetadataValue('edge:type');
         $v_type = $v->getMetadataValue('edge:type');
         if ($u_type == $v_type) {
           return $this->mergePHIDOrEdgeTransactions($u, $v);
         }
         return null;
     }
 
     // By default, do not merge the transactions.
     return null;
   }
 
   /**
    * Optionally expand transactions which imply other effects. For example,
    * resigning from a revision in Differential implies removing yourself as
    * a reviewer.
    */
   private function expandTransactions(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $results = array();
     foreach ($xactions as $xaction) {
       foreach ($this->expandTransaction($object, $xaction) as $expanded) {
         $results[] = $expanded;
       }
     }
 
     return $results;
   }
 
   protected function expandTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     return array($xaction);
   }
 
 
   private function expandSupportTransactions(
     PhabricatorLiskDAO $object,
     array $xactions) {
     $this->loadSubscribers($object);
 
     $xactions = $this->applyImplicitCC($object, $xactions);
 
     $blocks = array();
     foreach ($xactions as $key => $xaction) {
       $blocks[$key] = $this->getRemarkupBlocksFromTransaction($xaction);
     }
 
     $mention_xaction = $this->buildMentionTransaction(
       $object,
       $xactions,
       $blocks);
     if ($mention_xaction) {
       $xactions[] = $mention_xaction;
     }
 
     // TODO: For now, this is just a placeholder.
     $engine = PhabricatorMarkupEngine::getEngine('extract');
 
     $block_xactions = $this->expandRemarkupBlockTransactions(
       $object,
       $xactions,
       $blocks,
       $engine);
 
     foreach ($block_xactions as $xaction) {
       $xactions[] = $xaction;
     }
 
     return $xactions;
   }
 
   private function expandRemarkupBlockTransactions(
     PhabricatorLiskDAO $object,
     array $xactions,
     $blocks,
     PhutilMarkupEngine $engine) {
     return $this->expandCustomRemarkupBlockTransactions(
       $object,
       $xactions,
       $blocks,
       $engine);
   }
 
   protected function expandCustomRemarkupBlockTransactions(
     PhabricatorLiskDAO $object,
     array $xactions,
     $blocks,
     PhutilMarkupEngine $engine) {
     return array();
   }
 
 
   /**
    * Attempt to combine similar transactions into a smaller number of total
    * transactions. For example, two transactions which edit the title of an
    * object can be merged into a single edit.
    */
   private function combineTransactions(array $xactions) {
     $stray_comments = array();
 
     $result = array();
     $types = array();
     foreach ($xactions as $key => $xaction) {
       $type = $xaction->getTransactionType();
       if (isset($types[$type])) {
         foreach ($types[$type] as $other_key) {
           $merged = $this->mergeTransactions($result[$other_key], $xaction);
           if ($merged) {
             $result[$other_key] = $merged;
 
             if ($xaction->getComment() &&
                 ($xaction->getComment() !== $merged->getComment())) {
               $stray_comments[] = $xaction->getComment();
             }
 
             if ($result[$other_key]->getComment() &&
                 ($result[$other_key]->getComment() !== $merged->getComment())) {
               $stray_comments[] = $result[$other_key]->getComment();
             }
 
             // Move on to the next transaction.
             continue 2;
           }
         }
       }
       $result[$key] = $xaction;
       $types[$type][] = $key;
     }
 
     // If we merged any comments away, restore them.
     foreach ($stray_comments as $comment) {
       $xaction = newv(get_class(head($result)), array());
       $xaction->setTransactionType(PhabricatorTransactions::TYPE_COMMENT);
       $xaction->setComment($comment);
       $result[] = $xaction;
     }
 
     return array_values($result);
   }
 
   protected function mergePHIDOrEdgeTransactions(
     PhabricatorApplicationTransaction $u,
     PhabricatorApplicationTransaction $v) {
 
     $result = $u->getNewValue();
     foreach ($v->getNewValue() as $key => $value) {
       if ($u->getTransactionType() == PhabricatorTransactions::TYPE_EDGE) {
         if (empty($result[$key])) {
           $result[$key] = $value;
         } else {
           // We're merging two lists of edge adds, sets, or removes. Merge
           // them by merging individual PHIDs within them.
           $merged = $result[$key];
 
           foreach ($value as $dst => $v_spec) {
             if (empty($merged[$dst])) {
               $merged[$dst] = $v_spec;
             } else {
               // Two transactions are trying to perform the same operation on
               // the same edge. Normalize the edge data and then merge it. This
               // allows transactions to specify how data merges execute in a
               // precise way.
 
               $u_spec = $merged[$dst];
 
               if (!is_array($u_spec)) {
                 $u_spec = array('dst' => $u_spec);
               }
               if (!is_array($v_spec)) {
                 $v_spec = array('dst' => $v_spec);
               }
 
               $ux_data = idx($u_spec, 'data', array());
               $vx_data = idx($v_spec, 'data', array());
 
               $merged_data = $this->mergeEdgeData(
                 $u->getMetadataValue('edge:type'),
                 $ux_data,
                 $vx_data);
 
               $u_spec['data'] = $merged_data;
               $merged[$dst] = $u_spec;
             }
           }
 
           $result[$key] = $merged;
         }
       } else {
         $result[$key] = array_merge($value, idx($result, $key, array()));
       }
     }
     $u->setNewValue($result);
 
     // When combining an "ignore" transaction with a normal transaction, make
     // sure we don't propagate the "ignore" flag.
     if (!$v->getIgnoreOnNoEffect()) {
       $u->setIgnoreOnNoEffect(false);
     }
 
     return $u;
   }
 
   protected function mergeEdgeData($type, array $u, array $v) {
     return $v + $u;
   }
 
   protected function getPHIDTransactionNewValue(
     PhabricatorApplicationTransaction $xaction) {
 
     $old = array_fuse($xaction->getOldValue());
 
     $new = $xaction->getNewValue();
     $new_add = idx($new, '+', array());
     unset($new['+']);
     $new_rem = idx($new, '-', array());
     unset($new['-']);
     $new_set = idx($new, '=', null);
     if ($new_set !== null) {
       $new_set = array_fuse($new_set);
     }
     unset($new['=']);
 
     if ($new) {
       throw new Exception(
         "Invalid 'new' value for PHID transaction. Value should contain only ".
         "keys '+' (add PHIDs), '-' (remove PHIDs) and '=' (set PHIDS).");
     }
 
     $result = array();
 
     foreach ($old as $phid) {
       if ($new_set !== null && empty($new_set[$phid])) {
         continue;
       }
       $result[$phid] = $phid;
     }
 
     if ($new_set !== null) {
       foreach ($new_set as $phid) {
         $result[$phid] = $phid;
       }
     }
 
     foreach ($new_add as $phid) {
       $result[$phid] = $phid;
     }
 
     foreach ($new_rem as $phid) {
       unset($result[$phid]);
     }
 
     return array_values($result);
   }
 
   protected function getEdgeTransactionNewValue(
     PhabricatorApplicationTransaction $xaction) {
 
     $new = $xaction->getNewValue();
     $new_add = idx($new, '+', array());
     unset($new['+']);
     $new_rem = idx($new, '-', array());
     unset($new['-']);
     $new_set = idx($new, '=', null);
     unset($new['=']);
 
     if ($new) {
       throw new Exception(
         "Invalid 'new' value for Edge transaction. Value should contain only ".
         "keys '+' (add edges), '-' (remove edges) and '=' (set edges).");
     }
 
     $old = $xaction->getOldValue();
 
     $lists = array($new_set, $new_add, $new_rem);
     foreach ($lists as $list) {
       $this->checkEdgeList($list);
     }
 
     $result = array();
     foreach ($old as $dst_phid => $edge) {
       if ($new_set !== null && empty($new_set[$dst_phid])) {
         continue;
       }
       $result[$dst_phid] = $this->normalizeEdgeTransactionValue(
         $xaction,
         $edge,
         $dst_phid);
     }
 
     if ($new_set !== null) {
       foreach ($new_set as $dst_phid => $edge) {
         $result[$dst_phid] = $this->normalizeEdgeTransactionValue(
           $xaction,
           $edge,
           $dst_phid);
       }
     }
 
     foreach ($new_add as $dst_phid => $edge) {
       $result[$dst_phid] = $this->normalizeEdgeTransactionValue(
         $xaction,
         $edge,
         $dst_phid);
     }
 
     foreach ($new_rem as $dst_phid => $edge) {
       unset($result[$dst_phid]);
     }
 
     return $result;
   }
 
   private function checkEdgeList($list) {
     if (!$list) {
       return;
     }
     foreach ($list as $key => $item) {
       if (phid_get_type($key) === PhabricatorPHIDConstants::PHID_TYPE_UNKNOWN) {
         throw new Exception(
           "Edge transactions must have destination PHIDs as in edge ".
           "lists (found key '{$key}').");
       }
       if (!is_array($item) && $item !== $key) {
         throw new Exception(
           "Edge transactions must have PHIDs or edge specs as values ".
           "(found value '{$item}').");
       }
     }
   }
 
   private function normalizeEdgeTransactionValue(
     PhabricatorApplicationTransaction $xaction,
     $edge,
     $dst_phid) {
 
     if (!is_array($edge)) {
       if ($edge != $dst_phid) {
         throw new Exception(
           pht(
             'Transaction edge data must either be the edge PHID or an edge '.
             'specification dictionary.'));
       }
       $edge = array();
     } else {
       foreach ($edge as $key => $value) {
         switch ($key) {
           case 'src':
           case 'dst':
           case 'type':
           case 'data':
           case 'dateCreated':
           case 'dateModified':
           case 'seq':
           case 'dataID':
             break;
           default:
             throw new Exception(
               pht(
                 'Transaction edge specification contains unexpected key '.
                 '"%s".',
                 $key));
         }
       }
     }
 
     $edge['dst'] = $dst_phid;
 
     $edge_type = $xaction->getMetadataValue('edge:type');
     if (empty($edge['type'])) {
       $edge['type'] = $edge_type;
     } else {
       if ($edge['type'] != $edge_type) {
         $this_type = $edge['type'];
         throw new Exception(
           "Edge transaction includes edge of type '{$this_type}', but ".
           "transaction is of type '{$edge_type}'. Each edge transaction must ".
           "alter edges of only one type.");
       }
     }
 
     if (!isset($edge['data'])) {
       $edge['data'] = array();
     }
 
     return $edge;
   }
 
   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 == PhabricatorTransactions::TYPE_COMMENT) {
         $tail[] = $xaction;
       } else {
         $head[] = $xaction;
       }
     }
 
     return array_values(array_merge($head, $tail));
   }
 
 
   protected function filterTransactions(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $type_comment = PhabricatorTransactions::TYPE_COMMENT;
 
     $no_effect = array();
     $has_comment = false;
     $any_effect = false;
     foreach ($xactions as $key => $xaction) {
       if ($this->transactionHasEffect($object, $xaction)) {
         if ($xaction->getTransactionType() != $type_comment) {
           $any_effect = true;
         }
       } else if ($xaction->getIgnoreOnNoEffect()) {
         unset($xactions[$key]);
       } else {
         $no_effect[$key] = $xaction;
       }
       if ($xaction->hasComment()) {
         $has_comment = true;
       }
     }
 
     if (!$no_effect) {
       return $xactions;
     }
 
     if (!$this->getContinueOnNoEffect() && !$this->getIsPreview()) {
       throw new PhabricatorApplicationTransactionNoEffectException(
         $no_effect,
         $any_effect,
         $has_comment);
     }
 
     if (!$any_effect && !$has_comment) {
       // If we only have empty comment transactions, just drop them all.
       return array();
     }
 
     foreach ($no_effect as $key => $xaction) {
       if ($xaction->getComment()) {
         $xaction->setTransactionType($type_comment);
         $xaction->setOldValue(null);
         $xaction->setNewValue(null);
       } else {
         unset($xactions[$key]);
       }
     }
 
     return $xactions;
   }
 
 
   /**
    * Hook for validating transactions. This callback will be invoked for each
    * available transaction type, even if an edit does not apply any transactions
    * of that type. This allows you to raise exceptions when required fields are
    * missing, by detecting that the object has no field value and there is no
    * transaction which sets one.
    *
    * @param PhabricatorLiskDAO Object being edited.
    * @param string Transaction type to validate.
    * @param list<PhabricatorApplicationTransaction> Transactions of given type,
    *   which may be empty if the edit does not apply any transactions of the
    *   given type.
    * @return list<PhabricatorApplicationTransactionValidationError> List of
    *   validation errors.
    */
   protected function validateTransaction(
     PhabricatorLiskDAO $object,
     $type,
     array $xactions) {
 
     $errors = array();
     switch ($type) {
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         // Make sure the user isn't editing away their ability to edit this
         // object.
         foreach ($xactions as $xaction) {
           try {
             PhabricatorPolicyFilter::requireCapabilityWithForcedPolicy(
               $this->requireActor(),
               $object,
               PhabricatorPolicyCapability::CAN_EDIT,
               $xaction->getNewValue());
           } catch (PhabricatorPolicyException $ex) {
             $errors[] = array(
               new PhabricatorApplicationTransactionValidationError(
                 $type,
                 pht('Invalid'),
                 pht(
                   'You can not select this edit policy, because you would '.
                   'no longer be able to edit the object.'),
                 $xaction),
             );
           }
         }
         break;
       case PhabricatorTransactions::TYPE_CUSTOMFIELD:
         $groups = array();
         foreach ($xactions as $xaction) {
           $groups[$xaction->getMetadataValue('customfield:key')][] = $xaction;
         }
 
         $field_list = PhabricatorCustomField::getObjectFields(
           $object,
           PhabricatorCustomField::ROLE_EDIT);
 
         $role_xactions = PhabricatorCustomField::ROLE_APPLICATIONTRANSACTIONS;
         foreach ($field_list->getFields() as $field) {
           if (!$field->shouldEnableForRole($role_xactions)) {
             continue;
           }
           $errors[] = $field->validateApplicationTransactions(
             $this,
             $type,
             idx($groups, $field->getFieldKey(), array()));
         }
         break;
     }
 
     return array_mergev($errors);
   }
 
 
   /**
    * Check for a missing text field.
    *
    * A text field is missing if the object has no value and there are no
    * transactions which set a value, or if the transactions remove the value.
    * This method is intended to make implementing @{method:validateTransaction}
    * more convenient:
    *
    *   $missing = $this->validateIsEmptyTextField(
    *     $object->getName(),
    *     $xactions);
    *
    * This will return `true` if the net effect of the object and transactions
    * is an empty field.
    *
    * @param wild Current field value.
    * @param list<PhabricatorApplicationTransaction> Transactions editing the
    *          field.
    * @return bool True if the field will be an empty text field after edits.
    */
   protected function validateIsEmptyTextField($field_value, array $xactions) {
     if (strlen($field_value) && empty($xactions)) {
       return false;
     }
 
     if ($xactions && strlen(last($xactions)->getNewValue())) {
       return false;
     }
 
     return true;
   }
 
 
 /* -(  Implicit CCs  )------------------------------------------------------- */
 
 
   /**
    * When a user interacts with an object, we might want to add them to CC.
    */
   final public function applyImplicitCC(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     if (!($object instanceof PhabricatorSubscribableInterface)) {
       // If the object isn't subscribable, we can't CC them.
       return $xactions;
     }
 
     $actor_phid = $this->requireActor()->getPHID();
     if ($object->isAutomaticallySubscribed($actor_phid)) {
       // If they're auto-subscribed, don't CC them.
       return $xactions;
     }
 
     $should_cc = false;
     foreach ($xactions as $xaction) {
       if ($this->shouldImplyCC($object, $xaction)) {
         $should_cc = true;
         break;
       }
     }
 
     if (!$should_cc) {
       // Only some types of actions imply a CC (like adding a comment).
       return $xactions;
     }
 
     if ($object->getPHID()) {
       if (isset($this->subscribers[$actor_phid])) {
         // If the user is already subscribed, don't implicitly CC them.
         return $xactions;
       }
 
       $unsub = PhabricatorEdgeQuery::loadDestinationPHIDs(
         $object->getPHID(),
         PhabricatorEdgeConfig::TYPE_OBJECT_HAS_UNSUBSCRIBER);
       $unsub = array_fuse($unsub);
       if (isset($unsub[$actor_phid])) {
         // If the user has previously unsubscribed from this object explicitly,
         // don't implicitly CC them.
         return $xactions;
       }
     }
 
     $xaction = newv(get_class(head($xactions)), array());
     $xaction->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS);
     $xaction->setNewValue(array('+' => array($actor_phid)));
 
     array_unshift($xactions, $xaction);
 
     return $xactions;
   }
 
   protected function shouldImplyCC(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     return $xaction->isCommentTransaction();
   }
 
 
 /* -(  Sending Mail  )------------------------------------------------------- */
 
 
   /**
    * @task mail
    */
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
 
   /**
    * @task mail
    */
   protected function sendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $email_to = array_filter(array_unique($this->getMailTo($object)));
     $email_cc = array_filter(array_unique($this->getMailCC($object)));
 
     $phids = array_merge($email_to, $email_cc);
     $handles = id(new PhabricatorHandleQuery())
       ->setViewer($this->requireActor())
       ->withPHIDs($phids)
       ->execute();
 
     $template = $this->buildMailTemplate($object);
     $body = $this->buildMailBody($object, $xactions);
 
     $mail_tags = $this->getMailTags($object, $xactions);
 
     $action = $this->getStrongestAction($object, $xactions)->getActionName();
 
     $template
       ->setFrom($this->requireActor()->getPHID())
       ->setSubjectPrefix($this->getMailSubjectPrefix())
       ->setVarySubjectPrefix('['.$action.']')
       ->setThreadID($this->getMailThreadID($object), $this->getIsNewObject())
       ->setRelatedPHID($object->getPHID())
       ->setExcludeMailRecipientPHIDs($this->getExcludeMailRecipientPHIDs())
       ->setMailTags($mail_tags)
       ->setIsBulk(true)
       ->setBody($body->render());
 
     if ($this->getParentMessageID()) {
       $template->setParentMessageID($this->getParentMessageID());
     }
 
     $mails = $this
       ->buildReplyHandler($object)
       ->multiplexMail(
         $template,
         array_select_keys($handles, $email_to),
         array_select_keys($handles, $email_cc));
 
     foreach ($mails as $mail) {
       $mail->saveAndSend();
     }
 
     $template->addTos($email_to);
     $template->addCCs($email_cc);
 
     return $template;
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
     return $object->getPHID();
   }
 
 
   /**
    * @task mail
    */
   protected function getStrongestAction(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return last(msort($xactions, 'getActionStrength'));
   }
 
 
   /**
    * @task mail
    */
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     throw new Exception("Capability not supported.");
   }
 
 
   /**
    * @task mail
    */
   protected function getMailSubjectPrefix() {
     throw new Exception("Capability not supported.");
   }
 
 
   /**
    * @task mail
    */
   protected function getMailTags(
     PhabricatorLiskDAO $object,
     array $xactions) {
     $tags = array();
 
     foreach ($xactions as $xaction) {
       $tags[] = $xaction->getMailTags();
     }
 
     return array_mergev($tags);
   }
 
 
   /**
    * @task mail
    */
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     throw new Exception("Capability not supported.");
   }
 
 
   /**
    * @task mail
    */
   protected function getMailTo(PhabricatorLiskDAO $object) {
     throw new Exception("Capability not supported.");
   }
 
 
   /**
    * @task mail
    */
   protected function getMailCC(PhabricatorLiskDAO $object) {
     if ($object instanceof PhabricatorSubscribableInterface) {
       return $this->subscribers;
     }
     throw new Exception("Capability not supported.");
   }
 
 
   /**
    * @task mail
    */
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $headers = array();
     $comments = array();
 
     foreach ($xactions as $xaction) {
       if ($xaction->shouldHideForMail($xactions)) {
         continue;
       }
 
       $header = $xaction->getTitleForMail();
       if ($header !== null) {
         $headers[] = $header;
       }
 
       $comment = $xaction->getBodyForMail();
       if ($comment !== null) {
         $comments[] = $comment;
       }
     }
 
     $body = new PhabricatorMetaMTAMailBody();
     $body->addRawSection(implode("\n", $headers));
 
     foreach ($comments as $comment) {
       $body->addRawSection($comment);
     }
 
     return $body;
   }
 
 
 /* -(  Publishing Feed Stories  )-------------------------------------------- */
 
 
   /**
    * @task feed
    */
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
 
   /**
    * @task feed
    */
   protected function getFeedStoryType() {
     return 'PhabricatorApplicationTransactionFeedStory';
   }
 
 
   /**
    * @task feed
    */
   protected function getFeedRelatedPHIDs(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return array(
       $object->getPHID(),
       $this->requireActor()->getPHID(),
     );
   }
 
 
   /**
    * @task feed
    */
   protected function getFeedNotifyPHIDs(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return array_unique(array_merge(
       $this->getMailTo($object),
       $this->getMailCC($object)));
   }
 
 
   /**
    * @task feed
    */
   protected function getFeedStoryData(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $xactions = msort($xactions, 'getActionStrength');
     $xactions = array_reverse($xactions);
 
     return array(
       'objectPHID'        => $object->getPHID(),
       'transactionPHIDs'  => mpull($xactions, 'getPHID'),
     );
   }
 
 
   /**
    * @task feed
    */
   protected function publishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions,
     array $mailed_phids) {
 
     $xactions = mfilter($xactions, 'shouldHideForFeed', true);
     $related_phids = $this->getFeedRelatedPHIDs($object, $xactions);
     $subscribed_phids = $this->getFeedNotifyPHIDs($object, $xactions);
 
     $story_type = $this->getFeedStoryType();
     $story_data = $this->getFeedStoryData($object, $xactions);
 
     id(new PhabricatorFeedStoryPublisher())
       ->setStoryType($story_type)
       ->setStoryData($story_data)
       ->setStoryTime(time())
       ->setStoryAuthorPHID($this->requireActor()->getPHID())
       ->setRelatedPHIDs($related_phids)
       ->setPrimaryObjectPHID($object->getPHID())
       ->setSubscribedPHIDs($subscribed_phids)
       ->setMailRecipientPHIDs($mailed_phids)
       ->publish();
   }
 
 
 /* -(  Search Index  )------------------------------------------------------- */
 
 
   /**
    * @task search
    */
   protected function supportsSearch() {
     return false;
   }
 
 
 /* -(  Herald Integration )-------------------------------------------------- */
 
 
-  protected function supportsHerald() {
+  protected function shouldApplyHeraldRules(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
     return false;
   }
 
   protected function buildHeraldAdapter(
     PhabricatorLiskDAO $object,
     array $xactions) {
     throw new Exception('No herald adapter specified.');
   }
 
   private function setHeraldAdapter(HeraldAdapter $adapter) {
     $this->heraldAdapter = $adapter;
     return $this;
   }
 
   protected function getHeraldAdapter() {
     return $this->heraldAdapter;
   }
 
   private function setHeraldTranscript(HeraldTranscript $transcript) {
     $this->heraldTranscript = $transcript;
     return $this;
   }
 
   protected function getHeraldTranscript() {
     return $this->heraldTranscript;
   }
 
   private function applyHeraldRules(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $adapter = $this->buildHeraldAdapter($object, $xactions);
     $adapter->setContentSource($this->getContentSource());
     $adapter->setIsNewObject($this->getIsNewObject());
     $xscript = HeraldEngine::loadAndApplyRules($adapter);
 
     $this->setHeraldAdapter($adapter);
     $this->setHeraldTranscript($xscript);
 
-    $this->didApplyHeraldRules($object, $adapter, $xscript);
+    return $this->didApplyHeraldRules($object, $adapter, $xscript);
   }
 
   protected function didApplyHeraldRules(
     PhabricatorLiskDAO $object,
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
-
+    return array();
   }
 
 
 /* -(  Custom Fields  )------------------------------------------------------ */
 
 
   /**
    * @task customfield
    */
   private function getCustomFieldForTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $field_key = $xaction->getMetadataValue('customfield:key');
     if (!$field_key) {
       throw new Exception(
         "Custom field transaction has no 'customfield:key'!");
     }
 
     $field = PhabricatorCustomField::getObjectField(
       $object,
       PhabricatorCustomField::ROLE_APPLICATIONTRANSACTIONS,
       $field_key);
 
     if (!$field) {
       throw new Exception(
         "Custom field transaction has invalid 'customfield:key'; field ".
         "'{$field_key}' is disabled or does not exist.");
     }
 
     if (!$field->shouldAppearInApplicationTransactions()) {
       throw new Exception(
         "Custom field transaction '{$field_key}' does not implement ".
         "integration for ApplicationTransactions.");
     }
 
     $field->setViewer($this->getActor());
 
     return $field;
   }
 
 
 /* -(  Files  )-------------------------------------------------------------- */
 
 
   /**
    * Extract the PHIDs of any files which these transactions attach.
    *
    * @task files
    */
   private function extractFilePHIDs(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $blocks = array();
     foreach ($xactions as $xaction) {
       $blocks[] = $this->getRemarkupBlocksFromTransaction($xaction);
     }
     $blocks = array_mergev($blocks);
 
     $phids = array();
     if ($blocks) {
       $phids[] = PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
         $blocks);
     }
 
     foreach ($xactions as $xaction) {
       $phids[] = $this->extractFilePHIDsFromCustomTransaction(
         $object,
         $xaction);
     }
 
     $phids = array_unique(array_filter(array_mergev($phids)));
     if (!$phids) {
       return array();
     }
 
     // Only let a user attach files they can actually see, since this would
     // otherwise let you access any file by attaching it to an object you have
     // view permission on.
 
     $files = id(new PhabricatorFileQuery())
       ->setViewer($this->getActor())
       ->withPHIDs($phids)
       ->execute();
 
     return mpull($files, 'getPHID');
   }
 
   /**
    * @task files
    */
   protected function extractFilePHIDsFromCustomTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     return array();
   }
 
 
   /**
    * @task files
    */
   private function attachFiles(
     PhabricatorLiskDAO $object,
     array $file_phids) {
 
     if (!$file_phids) {
       return;
     }
 
     $editor = id(new PhabricatorEdgeEditor())
       ->setActor($this->getActor());
 
     // TODO: Edge-based events were almost certainly a terrible idea. If we
     // don't suppress this event, the Maniphest listener reenters and adds
     // more transactions. Just suppress it until that can get cleaned up.
     $editor->setSuppressEvents(true);
 
     $src = $object->getPHID();
     $type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_FILE;
     foreach ($file_phids as $dst) {
       $editor->addEdge($src, $type, $dst);
     }
 
     $editor->save();
   }
 
 }