diff --git a/src/applications/audit/editor/PhabricatorAuditCommentEditor.php b/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
index 6633e650a..25ef287a2 100644
--- a/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
+++ b/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
@@ -1,567 +1,568 @@
 <?php
 
 final class PhabricatorAuditCommentEditor extends PhabricatorEditor {
 
   private $commit;
 
   private $attachInlineComments;
   private $auditors = array();
   private $ccs = array();
 
   private $noEmail;
 
   public function __construct(PhabricatorRepositoryCommit $commit) {
     $this->commit = $commit;
     return $this;
   }
 
   public function addAuditors(array $auditor_phids) {
     $this->auditors = array_merge($this->auditors, $auditor_phids);
     return $this;
   }
 
   public function addCCs(array $cc_phids) {
     $this->ccs = array_merge($this->ccs, $cc_phids);
     return $this;
   }
 
   public function setAttachInlineComments($attach_inline_comments) {
     $this->attachInlineComments = $attach_inline_comments;
     return $this;
   }
 
   public function setNoEmail($no_email) {
     $this->noEmail = $no_email;
     return $this;
   }
 
   public function addComment(PhabricatorAuditComment $comment) {
 
     $commit = $this->commit;
     $actor = $this->getActor();
 
     $other_comments = id(new PhabricatorAuditComment())->loadAllWhere(
       'targetPHID = %s',
       $commit->getPHID());
 
     $inline_comments = array();
     if ($this->attachInlineComments) {
       $inline_comments = id(new PhabricatorAuditInlineComment())->loadAllWhere(
         'authorPHID = %s AND commitPHID = %s
           AND auditCommentID IS NULL',
         $actor->getPHID(),
         $commit->getPHID());
     }
 
     $comment
       ->setActorPHID($actor->getPHID())
       ->setTargetPHID($commit->getPHID())
       ->save();
 
     $content_blocks = array($comment->getContent());
 
     if ($inline_comments) {
       foreach ($inline_comments as $inline) {
         $inline->setAuditCommentID($comment->getID());
         $inline->save();
         $content_blocks[] = $inline->getContent();
       }
     }
 
     $ccs = $this->ccs;
     $auditors = $this->auditors;
 
     $metadata = $comment->getMetadata();
     $metacc = array();
 
     // Find any "@mentions" in the content blocks.
     $mention_ccs = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      $this->getActor(),
       $content_blocks);
     if ($mention_ccs) {
       $metacc = idx(
         $metadata,
         PhabricatorAuditComment::METADATA_ADDED_CCS,
         array());
       foreach ($mention_ccs as $cc_phid) {
         $metacc[] = $cc_phid;
       }
     }
 
     if ($metacc) {
       $ccs = array_merge($ccs, $metacc);
     }
 
     // When an actor submits an audit comment, we update all the audit requests
     // they have authority over to reflect the most recent status. The general
     // idea here is that if audit has triggered for, e.g., several packages, but
     // a user owns all of them, they can clear the audit requirement in one go
     // without auditing the commit for each trigger.
 
     $audit_phids = self::loadAuditPHIDsForUser($actor);
     $audit_phids = array_fill_keys($audit_phids, true);
 
     $requests = id(new PhabricatorRepositoryAuditRequest())
       ->loadAllWhere(
         'commitPHID = %s',
         $commit->getPHID());
 
     $action = $comment->getAction();
 
 
     // TODO: We should validate the action, currently we allow anyone to, e.g.,
     // close an audit if they muck with form parameters. I'll followup with this
     // and handle the no-effect cases (e.g., closing and already-closed audit).
 
 
     $actor_is_author = ($actor->getPHID() == $commit->getAuthorPHID());
 
     if ($action == PhabricatorAuditActionConstants::CLOSE) {
       if (!PhabricatorEnv::getEnvConfig('audit.can-author-close-audit')) {
           throw new Exception('Cannot Close Audit without enabling'.
           'audit.can-author-close-audit');
       }
       // "Close" means wipe out all the concerns.
       $concerned_status = PhabricatorAuditStatusConstants::CONCERNED;
       foreach ($requests as $request) {
         if ($request->getAuditStatus() == $concerned_status) {
           $request->setAuditStatus(PhabricatorAuditStatusConstants::CLOSED);
           $request->save();
         }
       }
     } else if ($action == PhabricatorAuditActionConstants::RESIGN) {
       // "Resign" has unusual rules for writing user rows, only affects the
       // user row (never package/project rows), and always affects the user
       // row (other actions don't, if they were able to affect a package/project
       // row).
       $actor_request = null;
       foreach ($requests as $request) {
         if ($request->getAuditorPHID() == $actor->getPHID()) {
           $actor_request = $request;
           break;
         }
       }
       if (!$actor_request) {
         $actor_request = id(new PhabricatorRepositoryAuditRequest())
           ->setCommitPHID($commit->getPHID())
           ->setAuditorPHID($actor->getPHID())
           ->setAuditReasons(array("Resigned"));
       }
 
       $actor_request
         ->setAuditStatus(PhabricatorAuditStatusConstants::RESIGNED)
         ->save();
 
       $requests[] = $actor_request;
     } else {
       $have_any_requests = false;
       foreach ($requests as $request) {
         if (empty($audit_phids[$request->getAuditorPHID()])) {
           continue;
         }
 
         $request_is_for_actor =
           ($request->getAuditorPHID() == $actor->getPHID());
 
         $have_any_requests = true;
         $new_status = null;
         switch ($action) {
           case PhabricatorAuditActionConstants::COMMENT:
           case PhabricatorAuditActionConstants::ADD_CCS:
           case PhabricatorAuditActionConstants::ADD_AUDITORS:
             // Commenting or adding cc's/auditors doesn't change status.
             break;
           case PhabricatorAuditActionConstants::ACCEPT:
             if (!$actor_is_author || $request_is_for_actor) {
               // When modifying your own commits, you act only on behalf of
               // yourself, not your packages/projects -- the idea being that
               // you can't accept your own commits.
               $new_status = PhabricatorAuditStatusConstants::ACCEPTED;
             }
             break;
           case PhabricatorAuditActionConstants::CONCERN:
             if (!$actor_is_author || $request_is_for_actor) {
               // See above.
               $new_status = PhabricatorAuditStatusConstants::CONCERNED;
             }
             break;
           default:
             throw new Exception("Unknown action '{$action}'!");
         }
         if ($new_status !== null) {
           $request->setAuditStatus($new_status);
           $request->save();
         }
       }
 
       // If the actor has no current authority over any audit trigger, make a
       // new one to represent their audit state.
       if (!$have_any_requests) {
         $new_status = null;
         switch ($action) {
           case PhabricatorAuditActionConstants::COMMENT:
           case PhabricatorAuditActionConstants::ADD_CCS:
           case PhabricatorAuditActionConstants::ADD_AUDITORS:
             $new_status = PhabricatorAuditStatusConstants::AUDIT_NOT_REQUIRED;
             break;
           case PhabricatorAuditActionConstants::ACCEPT:
             $new_status = PhabricatorAuditStatusConstants::ACCEPTED;
             break;
           case PhabricatorAuditActionConstants::CONCERN:
             $new_status = PhabricatorAuditStatusConstants::CONCERNED;
             break;
           case PhabricatorAuditActionConstants::CLOSE:
             // Impossible to reach this block with 'close'.
           default:
             throw new Exception("Unknown or invalid action '{$action}'!");
         }
 
         $request = id(new PhabricatorRepositoryAuditRequest())
           ->setCommitPHID($commit->getPHID())
           ->setAuditorPHID($actor->getPHID())
           ->setAuditStatus($new_status)
           ->setAuditReasons(array("Voluntary Participant"))
           ->save();
         $requests[] = $request;
       }
     }
 
     $requests_by_auditor = mpull($requests, null, 'getAuditorPHID');
     $requests_phids = array_keys($requests_by_auditor);
 
     $ccs = array_diff($ccs, $requests_phids);
     $auditors = array_diff($auditors, $requests_phids);
 
     if ($action == PhabricatorAuditActionConstants::ADD_CCS) {
       if ($ccs) {
         $metadata[PhabricatorAuditComment::METADATA_ADDED_CCS] = $ccs;
         $comment->setMetaData($metadata);
       } else {
         $comment->setAction(PhabricatorAuditActionConstants::COMMENT);
       }
     }
 
     if ($action == PhabricatorAuditActionConstants::ADD_AUDITORS) {
       if ($auditors) {
         $metadata[PhabricatorAuditComment::METADATA_ADDED_AUDITORS]
           = $auditors;
         $comment->setMetaData($metadata);
       } else {
         $comment->setAction(PhabricatorAuditActionConstants::COMMENT);
       }
     }
 
     $comment->save();
 
     if ($auditors) {
       foreach ($auditors as $auditor_phid) {
         $audit_requested = PhabricatorAuditStatusConstants::AUDIT_REQUESTED;
         $requests[] = id (new PhabricatorRepositoryAuditRequest())
           ->setCommitPHID($commit->getPHID())
           ->setAuditorPHID($auditor_phid)
           ->setAuditStatus($audit_requested)
           ->setAuditReasons(
             array('Added by ' . $actor->getUsername()))
           ->save();
       }
     }
 
     if ($ccs) {
       foreach ($ccs as $cc_phid) {
         $audit_cc = PhabricatorAuditStatusConstants::CC;
         $requests[] = id (new PhabricatorRepositoryAuditRequest())
           ->setCommitPHID($commit->getPHID())
           ->setAuditorPHID($cc_phid)
           ->setAuditStatus($audit_cc)
           ->setAuditReasons(
             array('Added by ' . $actor->getUsername()))
           ->save();
       }
     }
 
     $commit->updateAuditStatus($requests);
     $commit->save();
 
     $feed_dont_publish_phids = array();
     foreach ($requests as $request) {
       $status = $request->getAuditStatus();
       switch ($status) {
       case PhabricatorAuditStatusConstants::RESIGNED:
       case PhabricatorAuditStatusConstants::NONE:
       case PhabricatorAuditStatusConstants::AUDIT_NOT_REQUIRED:
       case PhabricatorAuditStatusConstants::CC:
         $feed_dont_publish_phids[$request->getAuditorPHID()] = 1;
         break;
       default:
         unset($feed_dont_publish_phids[$request->getAuditorPHID()]);
         break;
       }
     }
     $feed_dont_publish_phids = array_keys($feed_dont_publish_phids);
 
     $feed_phids = array_diff($requests_phids, $feed_dont_publish_phids);
     $this->publishFeedStory($comment, $feed_phids);
 
     id(new PhabricatorSearchIndexer())
       ->queueDocumentForIndexing($commit->getPHID());
 
     if (!$this->noEmail) {
       $this->sendMail($comment, $other_comments, $inline_comments, $requests);
     }
   }
 
 
   /**
    * Load the PHIDs for all objects the user has the authority to act as an
    * audit for. This includes themselves, and any packages they are an owner
    * of.
    */
   public static function loadAuditPHIDsForUser(PhabricatorUser $user) {
     $phids = array();
 
     // TODO: This method doesn't really use the right viewer, but in practice we
     // never issue this query of this type on behalf of another user and are
     // unlikely to do so in the future. This entire method should be refactored
     // into a Query class, however, and then we should use a proper viewer.
 
     // The user can audit on their own behalf.
     $phids[$user->getPHID()] = true;
 
     $owned_packages = id(new PhabricatorOwnersPackageQuery())
       ->setViewer($user)
       ->withOwnerPHIDs(array($user->getPHID()))
       ->execute();
     foreach ($owned_packages as $package) {
       $phids[$package->getPHID()] = true;
     }
 
     // The user can audit on behalf of all projects they are a member of.
     $projects = id(new PhabricatorProjectQuery())
       ->setViewer($user)
       ->withMemberPHIDs(array($user->getPHID()))
       ->execute();
     foreach ($projects as $project) {
       $phids[$project->getPHID()] = true;
     }
 
     return array_keys($phids);
   }
 
   private function publishFeedStory(
     PhabricatorAuditComment $comment,
     array $more_phids) {
 
     $commit = $this->commit;
     $actor = $this->getActor();
 
     $related_phids = array_merge(
       array(
         $actor->getPHID(),
         $commit->getPHID(),
       ),
       $more_phids);
 
     id(new PhabricatorFeedStoryPublisher())
       ->setRelatedPHIDs($related_phids)
       ->setStoryAuthorPHID($actor->getPHID())
       ->setStoryTime(time())
       ->setStoryType(PhabricatorFeedStoryTypeConstants::STORY_AUDIT)
       ->setStoryData(
         array(
           'commitPHID'    => $commit->getPHID(),
           'action'        => $comment->getAction(),
           'content'       => $comment->getContent(),
         ))
       ->publish();
   }
 
   private function sendMail(
     PhabricatorAuditComment $comment,
     array $other_comments,
     array $inline_comments,
     array $requests) {
 
     assert_instances_of($other_comments, 'PhabricatorAuditComment');
     assert_instances_of($inline_comments, 'PhabricatorInlineCommentInterface');
 
     $commit = $this->commit;
 
     $data = $commit->loadCommitData();
     $summary = $data->getSummary();
 
     $commit_phid = $commit->getPHID();
     $phids = array($commit_phid);
     $handles = id(new PhabricatorHandleQuery())
       ->setViewer($this->getActor())
       ->withPHIDs($phids)
       ->execute();
     $handle = $handles[$commit_phid];
 
     $name = $handle->getName();
 
     $map = array(
       PhabricatorAuditActionConstants::CONCERN  => 'Raised Concern',
       PhabricatorAuditActionConstants::ACCEPT   => 'Accepted',
       PhabricatorAuditActionConstants::RESIGN   => 'Resigned',
       PhabricatorAuditActionConstants::CLOSE    => 'Closed',
       PhabricatorAuditActionConstants::ADD_CCS => 'Added CCs',
       PhabricatorAuditActionConstants::ADD_AUDITORS => 'Added Auditors',
     );
     $verb = idx($map, $comment->getAction(), 'Commented On');
 
     $reply_handler = self::newReplyHandlerForCommit($commit);
 
     $prefix = PhabricatorEnv::getEnvConfig('metamta.diffusion.subject-prefix');
 
     $repository = id(new PhabricatorRepositoryQuery())
       ->setViewer($this->getActor())
       ->withIDs(array($commit->getRepositoryID()))
       ->executeOne();
     $threading = self::getMailThreading($repository, $commit);
     list($thread_id, $thread_topic) = $threading;
 
     $body = $this->renderMailBody(
       $comment,
       "{$name}: {$summary}",
       $handle,
       $reply_handler,
       $inline_comments);
 
     $email_to = array();
     $email_cc = array();
 
     $email_to[$comment->getActorPHID()] = true;
 
     $author_phid = $data->getCommitDetail('authorPHID');
     if ($author_phid) {
       $email_to[$author_phid] = true;
     }
 
     foreach ($other_comments as $other_comment) {
       $email_cc[$other_comment->getActorPHID()] = true;
     }
 
     foreach ($requests as $request) {
       switch ($request->getAuditStatus()) {
         case PhabricatorAuditStatusConstants::CC:
         case PhabricatorAuditStatusConstants::AUDIT_REQUIRED:
           $email_cc[$request->getAuditorPHID()] = true;
           break;
         case PhabricatorAuditStatusConstants::RESIGNED:
           unset($email_cc[$request->getAuditorPHID()]);
           break;
         case PhabricatorAuditStatusConstants::CONCERNED:
         case PhabricatorAuditStatusConstants::AUDIT_REQUESTED:
           $email_to[$request->getAuditorPHID()] = true;
           break;
       }
     }
 
     $email_to = array_keys($email_to);
     $email_cc = array_keys($email_cc);
 
     $phids = array_merge($email_to, $email_cc);
     $handles = id(new PhabricatorHandleQuery())
       ->setViewer($this->getActor())
       ->withPHIDs($phids)
       ->execute();
 
     // NOTE: Always set $is_new to false, because the "first" mail in the
     // thread is the Herald notification of the commit.
     $is_new = false;
 
     $template = id(new PhabricatorMetaMTAMail())
       ->setSubject("{$name}: {$summary}")
       ->setSubjectPrefix($prefix)
       ->setVarySubjectPrefix("[{$verb}]")
       ->setFrom($comment->getActorPHID())
       ->setThreadID($thread_id, $is_new)
       ->addHeader('Thread-Topic', $thread_topic)
       ->setRelatedPHID($commit->getPHID())
       ->setExcludeMailRecipientPHIDs($this->getExcludeMailRecipientPHIDs())
       ->setIsBulk(true)
       ->setBody($body);
 
     $mails = $reply_handler->multiplexMail(
       $template,
       array_select_keys($handles, $email_to),
       array_select_keys($handles, $email_cc));
 
     foreach ($mails as $mail) {
       $mail->saveAndSend();
     }
   }
 
   public static function getMailThreading(
     PhabricatorRepository $repository,
     PhabricatorRepositoryCommit $commit) {
 
     return array(
       'diffusion-audit-'.$commit->getPHID(),
       'Commit r'.$repository->getCallsign().$commit->getCommitIdentifier(),
     );
   }
 
   public static function newReplyHandlerForCommit($commit) {
     $reply_handler = PhabricatorEnv::newObjectFromConfig(
       'metamta.diffusion.reply-handler');
     $reply_handler->setMailReceiver($commit);
     return $reply_handler;
   }
 
   private function renderMailBody(
     PhabricatorAuditComment $comment,
     $cname,
     PhabricatorObjectHandle $handle,
     PhabricatorMailReplyHandler $reply_handler,
     array $inline_comments) {
     assert_instances_of($inline_comments, 'PhabricatorInlineCommentInterface');
 
     $commit = $this->commit;
     $actor = $this->getActor();
     $name = $actor->getUsername();
 
     $verb = PhabricatorAuditActionConstants::getActionPastTenseVerb(
       $comment->getAction());
 
     $body = new PhabricatorMetaMTAMailBody();
     $body->addRawSection("{$name} {$verb} commit {$cname}.");
     $body->addRawSection($comment->getContent());
 
     if ($inline_comments) {
       $block = array();
 
       $path_map = id(new DiffusionPathQuery())
         ->withPathIDs(mpull($inline_comments, 'getPathID'))
         ->execute();
       $path_map = ipull($path_map, 'path', 'id');
 
       foreach ($inline_comments as $inline) {
         $path = idx($path_map, $inline->getPathID());
         if ($path === null) {
           continue;
         }
 
         $start = $inline->getLineNumber();
         $len   = $inline->getLineLength();
         if ($len) {
           $range = $start.'-'.($start + $len);
         } else {
           $range = $start;
         }
 
         $content = $inline->getContent();
         $block[] = "{$path}:{$range} {$content}";
       }
 
       $body->addTextSection(pht('INLINE COMMENTS'), implode("\n", $block));
     }
 
     $body->addTextSection(
       pht('COMMIT'),
       PhabricatorEnv::getProductionURI($handle->getURI()));
     $body->addReplySection($reply_handler->getReplyHandlerInstructions());
 
     return $body->render();
   }
 
 }
diff --git a/src/applications/conpherence/conduit/ConduitAPI_conpherence_updatethread_Method.php b/src/applications/conpherence/conduit/ConduitAPI_conpherence_updatethread_Method.php
index 9d2022f27..229a50ce9 100644
--- a/src/applications/conpherence/conduit/ConduitAPI_conpherence_updatethread_Method.php
+++ b/src/applications/conpherence/conduit/ConduitAPI_conpherence_updatethread_Method.php
@@ -1,104 +1,107 @@
 <?php
 
 /**
  * @group conduit
  */
 final class ConduitAPI_conpherence_updatethread_Method
   extends ConduitAPI_conpherence_Method {
 
   public function getMethodDescription() {
     return pht('Update an existing conpherence thread.');
   }
 
   public function defineParamTypes() {
     return array(
       'id' => 'optional int',
       'phid' => 'optional phid',
       'title' => 'optional string',
       'message' => 'optional string',
       'addParticipantPHIDs' => 'optional list<phids>',
       'removeParticipantPHID' => 'optional phid'
     );
   }
 
   public function defineReturnType() {
     return 'bool';
   }
 
   public function defineErrorTypes() {
     return array(
       'ERR_USAGE_NO_THREAD_ID' => pht(
         'You must specify a thread id or thread phid to query transactions '.
         'from.'),
       'ERR_USAGE_THREAD_NOT_FOUND' => pht(
         'Thread does not exist or logged in user can not see it.'),
       'ERR_USAGE_ONLY_SELF_REMOVE' => pht(
         'Only a user can remove themselves from a thread.'),
       'ERR_USAGE_NO_UPDATES' => pht(
         'You must specify data that actually updates the conpherence.')
     );
   }
 
   protected function execute(ConduitAPIRequest $request) {
     $user = $request->getUser();
     $id = $request->getValue('id');
     $phid = $request->getValue('phid');
     $query = id(new ConpherenceThreadQuery())
       ->setViewer($user)
       ->needFilePHIDs(true);
     if ($id) {
       $query->withIDs(array($id));
     } else if ($phid) {
       $query->withPHIDs(array($phid));
     } else {
       throw new ConduitException('ERR_USAGE_NO_THREAD_ID');
     }
     $conpherence = $query->executeOne();
     if (!$conpherence) {
       throw new ConduitException('ERR_USAGE_THREAD_NOT_FOUND');
     }
 
     $source = PhabricatorContentSource::newFromConduitRequest($request);
     $editor = id(new ConpherenceEditor())
       ->setContentSource($source)
       ->setActor($user);
     $xactions = array();
     $add_participant_phids = $request->getValue('addParticipantPHIDs', array());
     $remove_participant_phid = $request->getValue('removeParticipantPHID');
     $message = $request->getValue('message');
     $title = $request->getValue('title');
     if ($add_participant_phids) {
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(
           ConpherenceTransactionType::TYPE_PARTICIPANTS)
         ->setNewValue(array('+' => $add_participant_phids));
     }
     if ($remove_participant_phid) {
       if ($remove_participant_phid != $user->getPHID()) {
         throw new ConduitException('ERR_USAGE_ONLY_SELF_REMOVE');
       }
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(
           ConpherenceTransactionType::TYPE_PARTICIPANTS)
         ->setNewValue(array('-' => array($remove_participant_phid)));
     }
     if ($title) {
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(ConpherenceTransactionType::TYPE_TITLE)
         ->setNewValue($title);
     }
     if ($message) {
       $xactions = array_merge(
         $xactions,
-        $editor->generateTransactionsFromText($conpherence, $message));
+        $editor->generateTransactionsFromText(
+          $user,
+          $conpherence,
+          $message));
     }
 
     try {
       $xactions = $editor->applyTransactions($conpherence, $xactions);
     } catch (PhabricatorApplicationTransactionNoEffectException $ex) {
       throw new ConduitException('ERR_USAGE_NO_UPDATES');
     }
 
     return true;
   }
 }
diff --git a/src/applications/conpherence/controller/ConpherenceUpdateController.php b/src/applications/conpherence/controller/ConpherenceUpdateController.php
index 2b631c313..9d87cfae1 100644
--- a/src/applications/conpherence/controller/ConpherenceUpdateController.php
+++ b/src/applications/conpherence/controller/ConpherenceUpdateController.php
@@ -1,346 +1,347 @@
 <?php
 
 final class ConpherenceUpdateController
   extends ConpherenceController {
 
   private $conpherenceID;
 
   public function setConpherenceID($conpherence_id) {
     $this->conpherenceID = $conpherence_id;
     return $this;
   }
   public function getConpherenceID() {
     return $this->conpherenceID;
   }
   public function willProcessRequest(array $data) {
     $this->setConpherenceID(idx($data, 'id'));
   }
 
   public function processRequest() {
     $request = $this->getRequest();
     $user = $request->getUser();
     $conpherence_id = $this->getConpherenceID();
     if (!$conpherence_id) {
       return new Aphront404Response();
     }
 
     $conpherence = id(new ConpherenceThreadQuery())
       ->setViewer($user)
       ->withIDs(array($conpherence_id))
       ->needFilePHIDs(true)
       ->executeOne();
 
     $action = $request->getStr('action', ConpherenceUpdateActions::METADATA);
     $latest_transaction_id = null;
     $response_mode = 'ajax';
     $error_view = null;
     $e_file = array();
     $errors = array();
     $delete_draft = false;
     $xactions = array();
     if ($request->isFormPost()) {
       $editor = id(new ConpherenceEditor())
         ->setContinueOnNoEffect($request->isContinueRequest())
         ->setContentSourceFromRequest($request)
         ->setActor($user);
 
       switch ($action) {
         case ConpherenceUpdateActions::DRAFT:
           $draft = PhabricatorDraft::newFromUserAndKey(
             $user,
             $conpherence->getPHID());
           $draft->setDraft($request->getStr('text'));
           $draft->replaceOrDelete();
           return new AphrontAjaxResponse();
         case ConpherenceUpdateActions::MESSAGE:
           $message = $request->getStr('text');
           $xactions = $editor->generateTransactionsFromText(
+            $user,
             $conpherence,
             $message);
           $delete_draft = true;
           break;
         case ConpherenceUpdateActions::ADD_PERSON:
           $person_phids = $request->getArr('add_person');
           if (!empty($person_phids)) {
             $xactions[] = id(new ConpherenceTransaction())
               ->setTransactionType(
                 ConpherenceTransactionType::TYPE_PARTICIPANTS)
               ->setNewValue(array('+' => $person_phids));
           }
           break;
         case ConpherenceUpdateActions::REMOVE_PERSON:
           if (!$request->isContinueRequest()) {
             // do nothing; we'll display a confirmation dialogue instead
             break;
           }
           $person_phid = $request->getStr('remove_person');
           if ($person_phid && $person_phid == $user->getPHID()) {
             $xactions[] = id(new ConpherenceTransaction())
               ->setTransactionType(
                 ConpherenceTransactionType::TYPE_PARTICIPANTS)
               ->setNewValue(array('-' => array($person_phid)));
             $response_mode = 'go-home';
           }
           break;
         case ConpherenceUpdateActions::NOTIFICATIONS:
           $notifications = $request->getStr('notifications');
           $participant = $conpherence->getParticipant($user->getPHID());
           $participant->setSettings(array('notifications' => $notifications));
           $participant->save();
           $result = pht(
             'Updated notification settings to "%s".',
             ConpherenceSettings::getHumanString($notifications));
           return id(new AphrontAjaxResponse())
             ->setContent($result);
           break;
         case ConpherenceUpdateActions::METADATA:
           $updated = false;
           // all metadata updates are continue requests
           if (!$request->isContinueRequest()) {
             break;
           }
 
           $title = $request->getStr('title');
           if ($title != $conpherence->getTitle()) {
             $xactions[] = id(new ConpherenceTransaction())
               ->setTransactionType(ConpherenceTransactionType::TYPE_TITLE)
               ->setNewValue($title);
             $updated = true;
             $response_mode = 'redirect';
           }
           if (!$updated) {
             $errors[] = pht(
               'That was a non-update. Try cancel.');
           }
           break;
         default:
           throw new Exception('Unknown action: '.$action);
           break;
       }
       if ($xactions) {
         try {
           $xactions = $editor->applyTransactions($conpherence, $xactions);
           if ($delete_draft) {
             $draft = PhabricatorDraft::newFromUserAndKey(
               $user,
               $conpherence->getPHID());
             $draft->delete();
           }
         } catch (PhabricatorApplicationTransactionNoEffectException $ex) {
           return id(new PhabricatorApplicationTransactionNoEffectResponse())
             ->setCancelURI($this->getApplicationURI($conpherence_id.'/'))
             ->setException($ex);
         }
         switch ($response_mode) {
           case 'ajax':
             $latest_transaction_id = $request->getInt('latest_transaction_id');
             $content = $this->loadAndRenderUpdates(
               $action,
               $conpherence_id,
               $latest_transaction_id);
             return id(new AphrontAjaxResponse())
               ->setContent($content);
             break;
           case 'go-home':
             return id(new AphrontRedirectResponse())
               ->setURI($this->getApplicationURI());
             break;
           case 'redirect':
           default:
             return id(new AphrontRedirectResponse())
               ->setURI($this->getApplicationURI($conpherence->getID().'/'));
             break;
         }
       }
     }
 
     if ($errors) {
       $error_view = id(new AphrontErrorView())
         ->setErrors($errors);
     }
 
     switch ($action) {
       case ConpherenceUpdateActions::ADD_PERSON:
         $dialogue = $this->renderAddPersonDialogue($conpherence);
         break;
       case ConpherenceUpdateActions::REMOVE_PERSON:
         $dialogue = $this->renderRemovePersonDialogue($conpherence);
         break;
       case ConpherenceUpdateActions::METADATA:
       default:
         $dialogue = $this->renderMetadataDialogue($conpherence, $error_view);
         break;
     }
 
     return id(new AphrontDialogResponse())
       ->setDialog($dialogue
         ->setUser($user)
         ->setWidth(AphrontDialogView::WIDTH_FORM)
         ->setSubmitURI($this->getApplicationURI('update/'.$conpherence_id.'/'))
         ->addSubmitButton()
         ->addCancelButton($this->getApplicationURI($conpherence->getID().'/')));
 
   }
 
   private function renderAddPersonDialogue(
     ConpherenceThread $conpherence) {
 
     $request = $this->getRequest();
     $user = $request->getUser();
     $add_person = $request->getStr('add_person');
 
     $form = id(new PHUIFormLayoutView())
       ->setUser($user)
       ->setFullWidth(true)
       ->appendChild(
         id(new AphrontFormTokenizerControl())
         ->setName('add_person')
         ->setUser($user)
         ->setDatasource('/typeahead/common/users/'));
 
     require_celerity_resource('conpherence-update-css');
     return id(new AphrontDialogView())
       ->setTitle(pht('Add Participants'))
       ->addHiddenInput('action', 'add_person')
       ->appendChild($form);
     }
 
   private function renderRemovePersonDialogue(
     ConpherenceThread $conpherence) {
 
     $request = $this->getRequest();
     $user = $request->getUser();
     $remove_person = $request->getStr('remove_person');
     $participants = $conpherence->getParticipants();
     $message = pht(
       'Are you sure you want to remove yourself from this conpherence? ');
     if (count($participants) == 1) {
       $message .= pht(
         'The conpherence will be inaccessible forever and ever.');
     } else {
       $message .= pht(
         'Someone else in the conpherence can add you back later.');
     }
     $body = phutil_tag(
       'p',
       array(
       ),
       $message);
 
     require_celerity_resource('conpherence-update-css');
     return id(new AphrontDialogView())
       ->setTitle(pht('Remove Participants'))
       ->addHiddenInput('action', 'remove_person')
       ->addHiddenInput('__continue__', true)
       ->addHiddenInput('remove_person', $remove_person)
       ->appendChild($body);
   }
 
   private function renderMetadataDialogue(
     ConpherenceThread $conpherence,
     $error_view) {
 
     $form = id(new PHUIFormLayoutView())
       ->appendChild($error_view)
       ->appendChild(
         id(new AphrontFormTextControl())
         ->setLabel(pht('Title'))
         ->setName('title')
         ->setValue($conpherence->getTitle()));
 
     require_celerity_resource('conpherence-update-css');
     return id(new AphrontDialogView())
       ->setTitle(pht('Update Conpherence'))
       ->addHiddenInput('action', 'metadata')
       ->addHiddenInput('__continue__', true)
       ->appendChild($form);
   }
 
   private function loadAndRenderUpdates(
     $action,
     $conpherence_id,
     $latest_transaction_id) {
 
     $need_widget_data = false;
     $need_transactions = false;
     switch ($action) {
       case ConpherenceUpdateActions::METADATA:
         $need_transactions = true;
         break;
       case ConpherenceUpdateActions::MESSAGE:
       case ConpherenceUpdateActions::ADD_PERSON:
         $need_transactions = true;
         $need_widget_data = true;
         break;
       case ConpherenceUpdateActions::REMOVE_PERSON:
       case ConpherenceUpdateActions::NOTIFICATIONS:
       default:
         break;
 
     }
     $user = $this->getRequest()->getUser();
     $conpherence = id(new ConpherenceThreadQuery())
       ->setViewer($user)
       ->setAfterTransactionID($latest_transaction_id)
       ->needWidgetData($need_widget_data)
       ->needTransactions($need_transactions)
       ->withIDs(array($conpherence_id))
       ->executeOne();
 
     if ($need_transactions) {
       $data = $this->renderConpherenceTransactions($conpherence);
     } else {
       $data = array();
     }
     $rendered_transactions = idx($data, 'transactions');
     $new_latest_transaction_id = idx($data, 'latest_transaction_id');
 
     $widget_uri = $this->getApplicationURI('update/'.$conpherence->getID().'/');
     $nav_item = null;
     $header = null;
     $people_widget = null;
     $file_widget = null;
     switch ($action) {
       case ConpherenceUpdateActions::METADATA:
         $header = $this->buildHeaderPaneContent($conpherence);
         $nav_item = id(new ConpherenceThreadListView())
           ->setUser($user)
           ->setBaseURI($this->getApplicationURI())
           ->renderSingleThread($conpherence);
         break;
       case ConpherenceUpdateActions::MESSAGE:
         $file_widget = id(new ConpherenceFileWidgetView())
           ->setUser($this->getRequest()->getUser())
           ->setConpherence($conpherence)
           ->setUpdateURI($widget_uri);
         break;
       case ConpherenceUpdateActions::ADD_PERSON:
         $people_widget = id(new ConpherencePeopleWidgetView())
           ->setUser($user)
           ->setConpherence($conpherence)
           ->setUpdateURI($widget_uri);
         break;
       case ConpherenceUpdateActions::REMOVE_PERSON:
       case ConpherenceUpdateActions::NOTIFICATIONS:
       default:
         break;
     }
 
     $people_html = null;
     if ($people_widget) {
       $people_html = hsprintf('%s', $people_widget->render());
     }
     $content = array(
       'transactions' => hsprintf('%s', $rendered_transactions),
       'latest_transaction_id' => $new_latest_transaction_id,
       'nav_item' => hsprintf('%s', $nav_item),
       'conpherence_phid' => $conpherence->getPHID(),
       'header' => hsprintf('%s', $header),
       'file_widget' => $file_widget ? $file_widget->render() : null,
       'people_widget' => $people_html,
     );
 
     return $content;
   }
 
 }
diff --git a/src/applications/conpherence/editor/ConpherenceEditor.php b/src/applications/conpherence/editor/ConpherenceEditor.php
index 249a87836..813fda858 100644
--- a/src/applications/conpherence/editor/ConpherenceEditor.php
+++ b/src/applications/conpherence/editor/ConpherenceEditor.php
@@ -1,412 +1,413 @@
 <?php
 
 /**
  * @group conpherence
  */
 final class ConpherenceEditor extends PhabricatorApplicationTransactionEditor {
 
   const ERROR_EMPTY_PARTICIPANTS = 'error-empty-participants';
   const ERROR_EMPTY_MESSAGE = 'error-empty-message';
 
   public static function createConpherence(
     PhabricatorUser $creator,
     array $participant_phids,
     $title,
     $message,
     PhabricatorContentSource $source) {
 
     $conpherence = id(new ConpherenceThread())
       ->attachParticipants(array())
       ->attachFilePHIDs(array())
       ->setMessageCount(0);
     $files = array();
     $errors = array();
     if (empty($participant_phids)) {
       $errors[] = self::ERROR_EMPTY_PARTICIPANTS;
     } else {
       $participant_phids[] = $creator->getPHID();
       $participant_phids = array_unique($participant_phids);
       $conpherence->setRecentParticipantPHIDs(
         array_slice($participant_phids, 0, 10));
     }
 
     if (empty($message)) {
       $errors[] = self::ERROR_EMPTY_MESSAGE;
     }
 
-    $file_phids =
-      PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
-        array($message));
+    $file_phids = PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
+      $creator,
+      array($message));
     if ($file_phids) {
       $files = id(new PhabricatorFileQuery())
         ->setViewer($creator)
         ->withPHIDs($file_phids)
         ->execute();
     }
 
     if (!$errors) {
       $xactions = array();
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(ConpherenceTransactionType::TYPE_PARTICIPANTS)
         ->setNewValue(array('+' => $participant_phids));
       if ($files) {
         $xactions[] = id(new ConpherenceTransaction())
           ->setTransactionType(ConpherenceTransactionType::TYPE_FILES)
           ->setNewValue(array('+' => mpull($files, 'getPHID')));
       }
       if ($title) {
         $xactions[] = id(new ConpherenceTransaction())
           ->setTransactionType(ConpherenceTransactionType::TYPE_TITLE)
           ->setNewValue($title);
       }
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
         ->attachComment(
           id(new ConpherenceTransactionComment())
           ->setContent($message)
           ->setConpherencePHID($conpherence->getPHID()));
 
       id(new ConpherenceEditor())
         ->setContentSource($source)
         ->setContinueOnNoEffect(true)
         ->setActor($creator)
         ->applyTransactions($conpherence, $xactions);
 
     }
 
     return array($errors, $conpherence);
   }
 
   public function generateTransactionsFromText(
+    PhabricatorUser $viewer,
     ConpherenceThread $conpherence,
     $text) {
 
     $files = array();
-    $file_phids =
-      PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
-        array($text));
+    $file_phids = PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
+      $viewer,
+      array($text));
     // Since these are extracted from text, we might be re-including the
     // same file -- e.g. a mock under discussion. Filter files we
     // already have.
     $existing_file_phids = $conpherence->getFilePHIDs();
     $file_phids = array_diff($file_phids, $existing_file_phids);
     if ($file_phids) {
       $files = id(new PhabricatorFileQuery())
         ->setViewer($this->getActor())
         ->withPHIDs($file_phids)
         ->execute();
     }
     $xactions = array();
     if ($files) {
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(ConpherenceTransactionType::TYPE_FILES)
         ->setNewValue(array('+' => mpull($files, 'getPHID')));
     }
     $xactions[] = id(new ConpherenceTransaction())
       ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
       ->attachComment(
         id(new ConpherenceTransactionComment())
         ->setContent($text)
         ->setConpherencePHID($conpherence->getPHID()));
     return $xactions;
   }
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
 
     $types[] = ConpherenceTransactionType::TYPE_TITLE;
     $types[] = ConpherenceTransactionType::TYPE_PARTICIPANTS;
     $types[] = ConpherenceTransactionType::TYPE_FILES;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ConpherenceTransactionType::TYPE_TITLE:
         return $object->getTitle();
       case ConpherenceTransactionType::TYPE_PARTICIPANTS:
         return $object->getParticipantPHIDs();
       case ConpherenceTransactionType::TYPE_FILES:
         return $object->getFilePHIDs();
     }
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ConpherenceTransactionType::TYPE_TITLE:
         return $xaction->getNewValue();
       case ConpherenceTransactionType::TYPE_PARTICIPANTS:
       case ConpherenceTransactionType::TYPE_FILES:
         return $this->getPHIDTransactionNewValue($xaction);
     }
   }
 
   /**
    * We really only need a read lock if we have a comment. In that case, we
    * must update the messagesCount field on the conpherence and
    * seenMessagesCount(s) for the participant(s).
    */
   protected function shouldReadLock(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $lock = false;
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         $lock =  true;
         break;
     }
 
     return $lock;
   }
 
   /**
    * We need to apply initial effects IFF the conpherence is new. We must
    * save the conpherence first thing to make sure we have an id and a phid.
    */
   protected function shouldApplyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return !$object->getID();
   }
 
   protected function applyInitialEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $object->save();
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         $object->setMessageCount((int)$object->getMessageCount() + 1);
         break;
       case ConpherenceTransactionType::TYPE_TITLE:
         $object->setTitle($xaction->getNewValue());
         break;
     }
     $this->updateRecentParticipantPHIDs($object, $xaction);
   }
 
   private function updateRecentParticipantPHIDs(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $participants = $object->getRecentParticipantPHIDs();
     array_unshift($participants, $xaction->getAuthorPHID());
     $participants = array_slice(array_unique($participants), 0, 10);
 
     $object->setRecentParticipantPHIDs($participants);
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case ConpherenceTransactionType::TYPE_FILES:
         $editor = id(new PhabricatorEdgeEditor())
           ->setActor($this->getActor());
         $edge_type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_FILE;
         $old = array_fill_keys($xaction->getOldValue(), true);
         $new = array_fill_keys($xaction->getNewValue(), true);
         $add_edges = array_keys(array_diff_key($new, $old));
         $remove_edges = array_keys(array_diff_key($old, $new));
         foreach ($add_edges as $file_phid) {
           $editor->addEdge(
             $object->getPHID(),
             $edge_type,
             $file_phid);
         }
         foreach ($remove_edges as $file_phid) {
           $editor->removeEdge(
             $object->getPHID(),
             $edge_type,
             $file_phid);
         }
         $editor->save();
         break;
       case ConpherenceTransactionType::TYPE_PARTICIPANTS:
         $participants = $object->getParticipants();
 
         $old_map = array_fuse($xaction->getOldValue());
         $new_map = array_fuse($xaction->getNewValue());
 
         $remove = array_keys(array_diff_key($old_map, $new_map));
         foreach ($remove as $phid) {
           $remove_participant = $participants[$phid];
           $remove_participant->delete();
           unset($participants[$phid]);
         }
 
         $add = array_keys(array_diff_key($new_map, $old_map));
         foreach ($add as $phid) {
           if ($phid == $this->getActor()->getPHID()) {
             $status = ConpherenceParticipationStatus::UP_TO_DATE;
             $message_count = $object->getMessageCount();
           } else {
             $status = ConpherenceParticipationStatus::BEHIND;
             $message_count = 0;
           }
           $participants[$phid] =
             id(new ConpherenceParticipant())
             ->setConpherencePHID($object->getPHID())
             ->setParticipantPHID($phid)
             ->setParticipationStatus($status)
             ->setDateTouched(time())
             ->setBehindTransactionPHID($xaction->getPHID())
             ->setSeenMessageCount($message_count)
             ->save();
         }
         $object->attachParticipants($participants);
         break;
     }
   }
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     // update everyone's participation status on the last xaction -only-
     $xaction = end($xactions);
     $xaction_phid = $xaction->getPHID();
     $behind = ConpherenceParticipationStatus::BEHIND;
     $up_to_date = ConpherenceParticipationStatus::UP_TO_DATE;
     $participants = $object->getParticipants();
     $user = $this->getActor();
     $time = time();
     foreach ($participants as $phid => $participant) {
       if ($phid != $user->getPHID()) {
         if ($participant->getParticipationStatus() != $behind) {
           $participant->setBehindTransactionPHID($xaction_phid);
           // decrement one as this is the message putting them behind!
           $participant->setSeenMessageCount($object->getMessageCount() - 1);
         }
         $participant->setParticipationStatus($behind);
         $participant->setDateTouched($time);
       } else {
         $participant->setSeenMessageCount($object->getMessageCount());
         $participant->setParticipationStatus($up_to_date);
         $participant->setDateTouched($time);
       }
       $participant->save();
     }
 
     return $xactions;
   }
 
   protected function mergeTransactions(
     PhabricatorApplicationTransaction $u,
     PhabricatorApplicationTransaction $v) {
 
     $type = $u->getTransactionType();
     switch ($type) {
       case ConpherenceTransactionType::TYPE_TITLE:
         return $v;
       case ConpherenceTransactionType::TYPE_FILES:
       case ConpherenceTransactionType::TYPE_PARTICIPANTS:
         return $this->mergePHIDOrEdgeTransactions($u, $v);
     }
 
     return parent::mergeTransactions($u, $v);
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new ConpherenceReplyHandler())
       ->setActor($this->getActor())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $title = $object->getTitle();
     if (!$title) {
       $title = pht(
         '%s sent you a message.',
         $this->getActor()->getUserName());
     }
     $phid = $object->getPHID();
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject("E{$id}: {$title}")
       ->addHeader('Thread-Topic', "E{$id}: {$phid}");
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     $to_phids = array();
     $participants = $object->getParticipants();
     if (empty($participants)) {
       return $to_phids;
     }
     $preferences = id(new PhabricatorUserPreferences())
       ->loadAllWhere('userPHID in (%Ls)', array_keys($participants));
     $preferences = mpull($preferences, null, 'getUserPHID');
     foreach ($participants as $phid => $participant) {
       $default = ConpherenceSettings::EMAIL_ALWAYS;
       $preference = idx($preferences, $phid);
       if ($preference) {
         $default = $preference->getPreference(
           PhabricatorUserPreferences::PREFERENCE_CONPH_NOTIFICATIONS,
           ConpherenceSettings::EMAIL_ALWAYS);
       }
       $settings = $participant->getSettings();
       $notifications = idx(
         $settings,
         'notifications',
         $default);
       if ($notifications == ConpherenceSettings::EMAIL_ALWAYS) {
         $to_phids[] = $phid;
       }
     }
     return $to_phids;
   }
 
   protected function getMailCC(PhabricatorLiskDAO $object) {
     return array();
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = parent::buildMailBody($object, $xactions);
     $body->addTextSection(
       pht('CONPHERENCE DETAIL'),
       PhabricatorEnv::getProductionURI('/conpherence/'.$object->getID().'/'));
 
     return $body;
   }
 
   protected function getMailSubjectPrefix() {
     return PhabricatorEnv::getEnvConfig('metamta.conpherence.subject-prefix');
   }
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return false;
   }
 
   protected function supportsSearch() {
     return false;
   }
 }
diff --git a/src/applications/conpherence/mail/ConpherenceReplyHandler.php b/src/applications/conpherence/mail/ConpherenceReplyHandler.php
index 5641d9d38..6c57db070 100644
--- a/src/applications/conpherence/mail/ConpherenceReplyHandler.php
+++ b/src/applications/conpherence/mail/ConpherenceReplyHandler.php
@@ -1,93 +1,94 @@
 <?php
 
 final class ConpherenceReplyHandler extends PhabricatorMailReplyHandler {
 
   private $mailAddedParticipantPHIDs;
 
   public function setMailAddedParticipantPHIDs(array $phids) {
     $this->mailAddedParticipantPHIDs = $phids;
     return $this;
   }
   public function getMailAddedParticipantPHIDs() {
     return $this->mailAddedParticipantPHIDs;
   }
 
   public function validateMailReceiver($mail_receiver) {
     if (!($mail_receiver instanceof ConpherenceThread)) {
       throw new Exception("Mail receiver is not a ConpherenceThread!");
     }
   }
 
   public function getPrivateReplyHandlerEmailAddress(
     PhabricatorObjectHandle $handle) {
     return $this->getDefaultPrivateReplyHandlerEmailAddress($handle, 'E');
   }
 
   public function getPublicReplyHandlerEmailAddress() {
     return $this->getDefaultPublicReplyHandlerEmailAddress('E');
   }
 
   public function getReplyHandlerInstructions() {
     if ($this->supportsReplies()) {
       return pht('Reply to comment and attach files.');
     } else {
       return null;
     }
   }
 
   protected function receiveEmail(PhabricatorMetaMTAReceivedMail $mail) {
     $conpherence = $this->getMailReceiver();
     $user = $this->getActor();
     if (!$conpherence->getPHID()) {
       $conpherence
         ->attachParticipants(array())
         ->attachFilePHIDs(array());
     } else {
       $edge_type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_FILE;
       $file_phids = PhabricatorEdgeQuery::loadDestinationPHIDs(
         $conpherence->getPHID(),
         $edge_type);
       $conpherence->attachFilePHIDs($file_phids);
       $participants = id(new ConpherenceParticipant())
         ->loadAllWhere('conpherencePHID = %s', $conpherence->getPHID());
       $participants = mpull($participants, null, 'getParticipantPHID');
       $conpherence->attachParticipants($participants);
     }
 
     $content_source = PhabricatorContentSource::newForSource(
       PhabricatorContentSource::SOURCE_EMAIL,
       array(
         'id' => $mail->getID(),
       ));
 
     $editor = id(new ConpherenceEditor())
       ->setActor($user)
       ->setContentSource($content_source)
       ->setParentMessageID($mail->getMessageID());
 
     $body = $mail->getCleanTextBody();
     $file_phids = $mail->getAttachments();
     $body = $this->enhanceBodyWithAttachments(
       $body,
       $file_phids,
       '{F%d}');
 
     $xactions = array();
     if ($this->getMailAddedParticipantPHIDs()) {
       $xactions[] = id(new ConpherenceTransaction())
         ->setTransactionType(ConpherenceTransactionType::TYPE_PARTICIPANTS)
         ->setNewValue(array('+' => $this->getMailAddedParticipantPHIDs()));
     }
 
     $xactions = array_merge(
       $xactions,
       $editor->generateTransactionsFromText(
+        $user,
         $conpherence,
         $body));
 
     $editor->applyTransactions($conpherence, $xactions);
 
     return $conpherence;
   }
 
 }
diff --git a/src/applications/maniphest/controller/ManiphestTransactionSaveController.php b/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
index 48686842e..3a623612d 100644
--- a/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
+++ b/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
@@ -1,213 +1,214 @@
 <?php
 
 final class ManiphestTransactionSaveController extends ManiphestController {
 
   public function processRequest() {
     $request = $this->getRequest();
     $user = $request->getUser();
 
     $task = id(new ManiphestTaskQuery())
       ->setViewer($user)
       ->withIDs(array($request->getStr('taskID')))
       ->executeOne();
     if (!$task) {
       return new Aphront404Response();
     }
 
     $task_uri = '/'.$task->getMonogram();
 
     $transactions = array();
 
     $action = $request->getStr('action');
 
     // Compute new CCs added by @mentions. Several things can cause CCs to
     // be added as side effects: mentions, explicit CCs, users who aren't
     // CC'd interacting with the task, and ownership changes. We build up a
     // list of all the CCs and then construct a transaction for them at the
     // end if necessary.
     $added_ccs = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      $user,
       array(
         $request->getStr('comments'),
       ));
 
     $cc_transaction = new ManiphestTransaction();
     $cc_transaction
       ->setTransactionType(ManiphestTransaction::TYPE_CCS);
 
     $transaction = new ManiphestTransaction();
     $transaction
       ->setTransactionType($action);
 
     switch ($action) {
       case ManiphestTransaction::TYPE_STATUS:
         $transaction->setNewValue($request->getStr('resolution'));
         break;
       case ManiphestTransaction::TYPE_OWNER:
         $assign_to = $request->getArr('assign_to');
         $assign_to = reset($assign_to);
         $transaction->setNewValue($assign_to);
         break;
       case ManiphestTransaction::TYPE_PROJECTS:
         $projects = $request->getArr('projects');
         $projects = array_merge($projects, $task->getProjectPHIDs());
         $projects = array_filter($projects);
         $projects = array_unique($projects);
         $transaction->setNewValue($projects);
         break;
       case ManiphestTransaction::TYPE_CCS:
         // Accumulate the new explicit CCs into the array that we'll add in
         // the CC transaction later.
         $added_ccs = array_merge($added_ccs, $request->getArr('ccs'));
 
         // Throw away the primary transaction.
         $transaction = null;
         break;
       case ManiphestTransaction::TYPE_PRIORITY:
         $transaction->setNewValue($request->getInt('priority'));
         break;
       case PhabricatorTransactions::TYPE_COMMENT:
         // Nuke this, we're going to create it below.
         $transaction = null;
         break;
       default:
         throw new Exception('unknown action');
     }
 
     if ($transaction) {
       $transactions[] = $transaction;
     }
 
     $resolution = $request->getStr('resolution');
     $did_scuttle = false;
     if ($action !== ManiphestTransaction::TYPE_STATUS) {
       if ($request->getStr('scuttle')) {
         $transactions[] = id(new ManiphestTransaction())
           ->setTransactionType(ManiphestTransaction::TYPE_STATUS)
           ->setNewValue(ManiphestTaskStatus::getDefaultClosedStatus());
         $did_scuttle = true;
         $resolution = ManiphestTaskStatus::getDefaultClosedStatus();
       }
     }
 
     // When you interact with a task, we add you to the CC list so you get
     // further updates, and possibly assign the task to you if you took an
     // ownership action (closing it) but it's currently unowned. We also move
     // previous owners to CC if ownership changes. Detect all these conditions
     // and create side-effect transactions for them.
 
     $implicitly_claimed = false;
     if ($action == ManiphestTransaction::TYPE_OWNER) {
       if ($task->getOwnerPHID() == $transaction->getNewValue()) {
         // If this is actually no-op, don't generate the side effect.
       } else {
         // Otherwise, when a task is reassigned, move the previous owner to CC.
         $added_ccs[] = $task->getOwnerPHID();
       }
     }
 
     if ($did_scuttle || ($action == ManiphestTransaction::TYPE_STATUS)) {
       if (!$task->getOwnerPHID() &&
           ManiphestTaskStatus::isClosedStatus($resolution)) {
         // Closing an unassigned task. Assign the user as the owner of
         // this task.
         $assign = new ManiphestTransaction();
         $assign->setTransactionType(ManiphestTransaction::TYPE_OWNER);
         $assign->setNewValue($user->getPHID());
         $transactions[] = $assign;
 
         $implicitly_claimed = true;
       }
     }
 
     $user_owns_task = false;
     if ($implicitly_claimed) {
       $user_owns_task = true;
     } else {
       if ($action == ManiphestTransaction::TYPE_OWNER) {
         if ($transaction->getNewValue() == $user->getPHID()) {
           $user_owns_task = true;
         }
       } else if ($task->getOwnerPHID() == $user->getPHID()) {
         $user_owns_task = true;
       }
     }
 
     if (!$user_owns_task) {
       // If we aren't making the user the new task owner and they aren't the
       // existing task owner, add them to CC unless they're aleady CC'd.
       if (!in_array($user->getPHID(), $task->getCCPHIDs())) {
         $added_ccs[] = $user->getPHID();
       }
     }
 
     // Evade no-effect detection in the new editor stuff until we can switch
     // to subscriptions.
     $added_ccs = array_filter(array_diff($added_ccs, $task->getCCPHIDs()));
 
     if ($added_ccs) {
       // We've added CCs, so include a CC transaction.
       $all_ccs = array_merge($task->getCCPHIDs(), $added_ccs);
       $cc_transaction->setNewValue($all_ccs);
       $transactions[] = $cc_transaction;
     }
 
     $comments = $request->getStr('comments');
     if (strlen($comments) || !$transactions) {
       $transactions[] = id(new ManiphestTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
         ->attachComment(
           id(new ManiphestTransactionComment())
             ->setContent($comments));
     }
 
     $event = new PhabricatorEvent(
       PhabricatorEventType::TYPE_MANIPHEST_WILLEDITTASK,
       array(
         'task'          => $task,
         'new'           => false,
         'transactions'  => $transactions,
       ));
     $event->setUser($user);
     $event->setAphrontRequest($request);
     PhutilEventEngine::dispatchEvent($event);
 
     $task = $event->getValue('task');
     $transactions = $event->getValue('transactions');
 
     $editor = id(new ManiphestTransactionEditor())
       ->setActor($user)
       ->setContentSourceFromRequest($request)
       ->setContinueOnMissingFields(true)
       ->setContinueOnNoEffect($request->isContinueRequest());
 
     try {
       $editor->applyTransactions($task, $transactions);
     } catch (PhabricatorApplicationTransactionNoEffectException $ex) {
       return id(new PhabricatorApplicationTransactionNoEffectResponse())
         ->setCancelURI($task_uri)
         ->setException($ex);
     }
 
     $draft = id(new PhabricatorDraft())->loadOneWhere(
       'authorPHID = %s AND draftKey = %s',
       $user->getPHID(),
       $task->getPHID());
     if ($draft) {
       $draft->delete();
     }
 
     $event = new PhabricatorEvent(
       PhabricatorEventType::TYPE_MANIPHEST_DIDEDITTASK,
       array(
         'task'          => $task,
         'new'           => false,
         'transactions'  => $transactions,
       ));
     $event->setUser($user);
     $event->setAphrontRequest($request);
     PhutilEventEngine::dispatchEvent($event);
 
     return id(new AphrontRedirectResponse())->setURI($task_uri);
   }
 
 }
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
index dc43764c7..ff1399fd4 100644
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -1,2240 +1,2243 @@
 <?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;
   private $disableEmail;
 
   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;
   }
 
   public 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;
   }
 
   /**
    * Prevent this editor from generating email when applying transactions.
    *
    * @param bool  True to disable email.
    * @return this
    */
   public function setDisableEmail($disable_email) {
     $this->disableEmail = $disable_email;
     return $this;
   }
 
   public function getDisableEmail() {
     return $this->disableEmail;
   }
 
   public function getTransactionTypes() {
     $types = array();
 
     if ($this->object instanceof PhabricatorSubscribableInterface) {
       $types[] = PhabricatorTransactions::TYPE_SUBSCRIBERS;
     }
 
     if ($this->object instanceof PhabricatorCustomFieldInterface) {
       $types[] = PhabricatorTransactions::TYPE_CUSTOMFIELD;
     }
 
     if ($this->object instanceof HarbormasterBuildableInterface) {
       $types[] = PhabricatorTransactions::TYPE_BUILDABLE;
     }
 
     if ($this->object instanceof PhabricatorTokenReceiverInterface) {
       $types[] = PhabricatorTransactions::TYPE_TOKEN;
     }
 
     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:
       case PhabricatorTransactions::TYPE_BUILDABLE:
       case PhabricatorTransactions::TYPE_TOKEN:
         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_BUILDABLE:
       case PhabricatorTransactions::TYPE_TOKEN:
         return;
       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_BUILDABLE:
       case PhabricatorTransactions::TYPE_TOKEN:
         return;
       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);
 
     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 setContentSourceFromConduitRequest(
     ConduitAPIRequest $request) {
 
     $content_source = PhabricatorContentSource::newForSource(
       PhabricatorContentSource::SOURCE_CONDUIT,
       array());
 
     return $this->setContentSource($content_source);
   }
 
   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);
       }
 
       $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) {
         $xscript_id = $this->getHeraldTranscript()->getID();
         foreach ($herald_xactions as $herald_xaction) {
           $herald_xaction->setMetadataValue('herald:transcriptID', $xscript_id);
         }
 
         // 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);
       }
     }
 
     // Before sending mail or publishing feed stories, reload the object
     // subscribers to pick up changes caused by Herald (or by other side effects
     // in various transaction phases).
     $this->loadSubscribers($object);
 
     $this->loadHandles($xactions);
 
     $mail = null;
     if (!$this->getDisableEmail()) {
       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)));
       }
     }
   }
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     if ($this->getIsNewObject()) {
       return;
     }
 
     $actor = $this->requireActor();
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_COMMENT:
         PhabricatorPolicyFilter::requireCapability(
           $actor,
           $object,
           PhabricatorPolicyCapability::CAN_VIEW);
         break;
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         PhabricatorPolicyFilter::requireCapability(
           $actor,
           $object,
           PhabricatorPolicyCapability::CAN_EDIT);
         break;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         PhabricatorPolicyFilter::requireCapability(
           $actor,
           $object,
           PhabricatorPolicyCapability::CAN_EDIT);
         break;
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         PhabricatorPolicyFilter::requireCapability(
           $actor,
           $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);
+    $phids = PhabricatorMarkupEngine::extractPHIDsFromMentions(
+      $this->getActor(),
+      $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_VIEW_POLICY:
         $errors[] = $this->validatePolicyTransaction(
           $object,
           $xactions,
           $type,
           PhabricatorPolicyCapability::CAN_VIEW);
         break;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $errors[] = $this->validatePolicyTransaction(
           $object,
           $xactions,
           $type,
           PhabricatorPolicyCapability::CAN_EDIT);
         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);
         $field_list->setViewer($this->getActor());
 
         $role_xactions = PhabricatorCustomField::ROLE_APPLICATIONTRANSACTIONS;
         foreach ($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);
   }
 
   private function validatePolicyTransaction(
     PhabricatorLiskDAO $object,
     array $xactions,
     $transaction_type,
     $capability) {
 
     $actor = $this->requireActor();
     $errors = array();
     // Note $this->xactions is necessary; $xactions is $this->xactions of
     // $transaction_type
     $policy_object = $this->adjustObjectForPolicyChecks(
       $object,
       $this->xactions);
 
     // Make sure the user isn't editing away their ability to $capability this
     // object.
     foreach ($xactions as $xaction) {
       try {
         PhabricatorPolicyFilter::requireCapabilityWithForcedPolicy(
           $actor,
           $policy_object,
           $capability,
           $xaction->getNewValue());
       } catch (PhabricatorPolicyException $ex) {
         $errors[] = new PhabricatorApplicationTransactionValidationError(
           $transaction_type,
           pht('Invalid'),
           pht(
             'You can not select this %s policy, because you would no longer '.
             'be able to %s the object.',
             $capability,
             $capability),
           $xaction);
       }
     }
 
     if ($this->getIsNewObject()) {
       if (!$xactions) {
         $has_capability = PhabricatorPolicyFilter::hasCapability(
           $actor,
           $policy_object,
           $capability);
         if (!$has_capability) {
           $errors[] = new PhabricatorApplicationTransactionValidationError(
             $transaction_type,
             pht('Invalid'),
             pht('The selected %s policy excludes you. Choose a %s policy '.
                 'which allows you to %s the object.',
             $capability,
             $capability,
             $capability));
         }
       }
     }
 
     return $errors;
   }
 
   protected function adjustObjectForPolicyChecks(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     return clone $object;
   }
 
   /**
    * 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) {
 
     // Check if any of the transactions are visible. If we don't have any
     // visible transactions, don't send the mail.
 
     $any_visible = false;
     foreach ($xactions as $xaction) {
       if (!$xaction->shouldHideForMail($xactions)) {
         $any_visible = true;
         break;
       }
     }
 
     if (!$any_visible) {
       return;
     }
 
     $email_to = array_filter(array_unique($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 = $this->getMailAction($object, $xactions);
 
     $reply_handler = $this->buildReplyHandler($object);
     $reply_section = $reply_handler->getReplyHandlerInstructions();
     if ($reply_section !== null) {
       $body->addReplySection($reply_section);
     }
 
     $template
       ->setFrom($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());
 
     foreach ($body->getAttachments() as $attachment) {
       $template->addAttachment($attachment);
     }
 
     $herald_xscript = $this->getHeraldTranscript();
     if ($herald_xscript) {
       $herald_header = $herald_xscript->getXHeraldRulesHeader();
       $herald_header = HeraldTranscript::saveXHeraldRulesHeader(
         $object->getPHID(),
         $herald_header);
     } else {
       $herald_header = HeraldTranscript::loadXHeraldRulesHeader(
         $object->getPHID());
     }
 
     if ($herald_header) {
       $template->addHeader('X-Herald-Rules', $herald_header);
     }
 
     if ($this->getParentMessageID()) {
       $template->setParentMessageID($this->getParentMessageID());
     }
 
     $mails = $reply_handler->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 getMailAction(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return $this->getStrongestAction($object, $xactions)->getActionName();
   }
 
 
   /**
    * @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);
     }
 
     if ($object instanceof PhabricatorCustomFieldInterface) {
       $field_list = PhabricatorCustomField::getObjectFields(
         $object,
         PhabricatorCustomField::ROLE_TRANSACTIONMAIL);
       $field_list->setViewer($this->getActor());
       $field_list->readFieldsFromStorage($object);
 
       foreach ($field_list->getFields() as $field) {
         $field->updateTransactionMailBody(
           $body,
           $this,
           $xactions);
       }
     }
 
     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);
 
     if (!$xactions) {
       return;
     }
 
     $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 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);
 
     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(
+        $this->getActor(),
         $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();
   }
 
 }
diff --git a/src/infrastructure/markup/PhabricatorMarkupEngine.php b/src/infrastructure/markup/PhabricatorMarkupEngine.php
index 20a211177..87555f1d6 100644
--- a/src/infrastructure/markup/PhabricatorMarkupEngine.php
+++ b/src/infrastructure/markup/PhabricatorMarkupEngine.php
@@ -1,593 +1,597 @@
 <?php
 
 /**
  * Manages markup engine selection, configuration, application, caching and
  * pipelining.
  *
  * @{class:PhabricatorMarkupEngine} can be used to render objects which
  * implement @{interface:PhabricatorMarkupInterface} in a batched, cache-aware
  * way. For example, if you have a list of comments written in remarkup (and
  * the objects implement the correct interface) you can render them by first
  * building an engine and adding the fields with @{method:addObject}.
  *
  *   $field  = 'field:body'; // Field you want to render. Each object exposes
  *                           // one or more fields of markup.
  *
  *   $engine = new PhabricatorMarkupEngine();
  *   foreach ($comments as $comment) {
  *     $engine->addObject($comment, $field);
  *   }
  *
  * Now, call @{method:process} to perform the actual cache/rendering
  * step. This is a heavyweight call which does batched data access and
  * transforms the markup into output.
  *
  *   $engine->process();
  *
  * Finally, do something with the results:
  *
  *   $results = array();
  *   foreach ($comments as $comment) {
  *     $results[] = $engine->getOutput($comment, $field);
  *   }
  *
  * If you have a single object to render, you can use the convenience method
  * @{method:renderOneObject}.
  *
  * @task markup Markup Pipeline
  * @task engine Engine Construction
  */
 final class PhabricatorMarkupEngine {
 
   private $objects = array();
   private $viewer;
   private $version = 8;
 
 
 /* -(  Markup Pipeline  )---------------------------------------------------- */
 
 
   /**
    * Convenience method for pushing a single object through the markup
    * pipeline.
    *
    * @param PhabricatorMarkupInterface  The object to render.
    * @param string                      The field to render.
    * @param PhabricatorUser             User viewing the markup.
    * @return string                     Marked up output.
    * @task markup
    */
   public static function renderOneObject(
     PhabricatorMarkupInterface $object,
     $field,
     PhabricatorUser $viewer) {
     return id(new PhabricatorMarkupEngine())
       ->setViewer($viewer)
       ->addObject($object, $field)
       ->process()
       ->getOutput($object, $field);
   }
 
 
   /**
    * Queue an object for markup generation when @{method:process} is
    * called. You can retrieve the output later with @{method:getOutput}.
    *
    * @param PhabricatorMarkupInterface  The object to render.
    * @param string                      The field to render.
    * @return this
    * @task markup
    */
   public function addObject(PhabricatorMarkupInterface $object, $field) {
     $key = $this->getMarkupFieldKey($object, $field);
     $this->objects[$key] = array(
       'object' => $object,
       'field'  => $field,
     );
 
     return $this;
   }
 
 
   /**
    * Process objects queued with @{method:addObject}. You can then retrieve
    * the output with @{method:getOutput}.
    *
    * @return this
    * @task markup
    */
   public function process() {
     $keys = array();
     foreach ($this->objects as $key => $info) {
       if (!isset($info['markup'])) {
         $keys[] = $key;
       }
     }
 
     if (!$keys) {
       return;
     }
 
     $objects = array_select_keys($this->objects, $keys);
 
     // Build all the markup engines. We need an engine for each field whether
     // we have a cache or not, since we still need to postprocess the cache.
     $engines = array();
     foreach ($objects as $key => $info) {
       $engines[$key] = $info['object']->newMarkupEngine($info['field']);
       $engines[$key]->setConfig('viewer', $this->viewer);
     }
 
     // Load or build the preprocessor caches.
     $blocks = $this->loadPreprocessorCaches($engines, $objects);
     $blocks = mpull($blocks, 'getCacheData');
 
     $this->engineCaches = $blocks;
 
     // Finalize the output.
     foreach ($objects as $key => $info) {
       $engine = $engines[$key];
       $field = $info['field'];
       $object = $info['object'];
 
       $output = $engine->postprocessText($blocks[$key]);
       $output = $object->didMarkupText($field, $output, $engine);
       $this->objects[$key]['output'] = $output;
     }
 
     return $this;
   }
 
 
   /**
    * Get the output of markup processing for a field queued with
    * @{method:addObject}. Before you can call this method, you must call
    * @{method:process}.
    *
    * @param PhabricatorMarkupInterface  The object to retrieve.
    * @param string                      The field to retrieve.
    * @return string                     Processed output.
    * @task markup
    */
   public function getOutput(PhabricatorMarkupInterface $object, $field) {
     $key = $this->getMarkupFieldKey($object, $field);
     $this->requireKeyProcessed($key);
 
     return $this->objects[$key]['output'];
   }
 
 
   /**
    * Retrieve engine metadata for a given field.
    *
    * @param PhabricatorMarkupInterface  The object to retrieve.
    * @param string                      The field to retrieve.
    * @param string                      The engine metadata field to retrieve.
    * @param wild                        Optional default value.
    * @task markup
    */
   public function getEngineMetadata(
     PhabricatorMarkupInterface $object,
     $field,
     $metadata_key,
     $default = null) {
 
     $key = $this->getMarkupFieldKey($object, $field);
     $this->requireKeyProcessed($key);
 
     return idx($this->engineCaches[$key]['metadata'], $metadata_key, $default);
   }
 
 
   /**
    * @task markup
    */
   private function requireKeyProcessed($key) {
     if (empty($this->objects[$key])) {
       throw new Exception(
         "Call addObject() before using results (key = '{$key}').");
     }
 
     if (!isset($this->objects[$key]['output'])) {
       throw new Exception(
         "Call process() before using results.");
     }
   }
 
 
   /**
    * @task markup
    */
   private function getMarkupFieldKey(
     PhabricatorMarkupInterface $object,
     $field) {
 
     static $custom;
     if ($custom === null) {
       $custom = array_merge(
         self::loadCustomInlineRules(),
         self::loadCustomBlockRules());
 
       $custom = mpull($custom, 'getRuleVersion', null);
       ksort($custom);
       $custom = PhabricatorHash::digestForIndex(serialize($custom));
     }
 
     return $object->getMarkupFieldKey($field).'@'.$this->version.'@'.$custom;
   }
 
 
   /**
    * @task markup
    */
   private function loadPreprocessorCaches(array $engines, array $objects) {
     $blocks = array();
 
     $use_cache = array();
     foreach ($objects as $key => $info) {
       if ($info['object']->shouldUseMarkupCache($info['field'])) {
         $use_cache[$key] = true;
       }
     }
 
     if ($use_cache) {
       try {
         $blocks = id(new PhabricatorMarkupCache())->loadAllWhere(
           'cacheKey IN (%Ls)',
           array_keys($use_cache));
         $blocks = mpull($blocks, null, 'getCacheKey');
       } catch (Exception $ex) {
         phlog($ex);
       }
     }
 
     foreach ($objects as $key => $info) {
       // False check in case MySQL doesn't support unicode characters
       // in the string (T1191), resulting in unserialize returning false.
       if (isset($blocks[$key]) && $blocks[$key]->getCacheData() !== false) {
         // If we already have a preprocessing cache, we don't need to rebuild
         // it.
         continue;
       }
 
       $text = $info['object']->getMarkupText($info['field']);
       $data = $engines[$key]->preprocessText($text);
 
       // NOTE: This is just debugging information to help sort out cache issues.
       // If one machine is misconfigured and poisoning caches you can use this
       // field to hunt it down.
 
       $metadata = array(
         'host' => php_uname('n'),
       );
 
       $blocks[$key] = id(new PhabricatorMarkupCache())
         ->setCacheKey($key)
         ->setCacheData($data)
         ->setMetadata($metadata);
 
       if (isset($use_cache[$key])) {
         // This is just filling a cache and always safe, even on a read pathway.
         $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
           $blocks[$key]->replace();
         unset($unguarded);
       }
     }
 
     return $blocks;
   }
 
 
   /**
    * Set the viewing user. Used to implement object permissions.
    *
    * @param PhabricatorUser The viewing user.
    * @return this
    * @task markup
    */
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
 
 /* -(  Engine Construction  )------------------------------------------------ */
 
 
 
   /**
    * @task engine
    */
   public static function newManiphestMarkupEngine() {
     return self::newMarkupEngine(array(
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newPhrictionMarkupEngine() {
     return self::newMarkupEngine(array(
       'header.generate-toc' => true,
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newPhameMarkupEngine() {
     return self::newMarkupEngine(array(
       'macros' => false,
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newFeedMarkupEngine() {
     return self::newMarkupEngine(
       array(
         'macros'      => false,
         'youtube'     => false,
 
       ));
   }
 
 
   /**
    * @task engine
    */
   public static function newDifferentialMarkupEngine(array $options = array()) {
     return self::newMarkupEngine(array(
       'differential.diff' => idx($options, 'differential.diff'),
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newDiffusionMarkupEngine(array $options = array()) {
     return self::newMarkupEngine(array(
       'header.generate-toc' => true,
     ));
   }
 
   /**
    * @task engine
    */
   public static function getEngine($ruleset = 'default') {
     static $engines = array();
     if (isset($engines[$ruleset])) {
       return $engines[$ruleset];
     }
 
     $engine = null;
     switch ($ruleset) {
       case 'default':
         $engine = self::newMarkupEngine(array());
         break;
       case 'nolinebreaks':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('preserve-linebreaks', false);
         break;
       case 'diviner':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('preserve-linebreaks', false);
   //    $engine->setConfig('diviner.renderer', new DivinerDefaultRenderer());
         $engine->setConfig('header.generate-toc', true);
         break;
       case 'extract':
         // Engine used for reference/edge extraction. Turn off anything which
         // is slow and doesn't change reference extraction.
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('pygments.enabled', false);
         break;
       default:
         throw new Exception("Unknown engine ruleset: {$ruleset}!");
     }
 
     $engines[$ruleset] = $engine;
     return $engine;
   }
 
   /**
    * @task engine
    */
   private static function getMarkupEngineDefaultConfiguration() {
     return array(
       'pygments'      => PhabricatorEnv::getEnvConfig('pygments.enabled'),
       'youtube'       => PhabricatorEnv::getEnvConfig(
         'remarkup.enable-embedded-youtube'),
       'differential.diff' => null,
       'header.generate-toc' => false,
       'macros'        => true,
       'uri.allowed-protocols' => PhabricatorEnv::getEnvConfig(
         'uri.allowed-protocols'),
       'syntax-highlighter.engine' => PhabricatorEnv::getEnvConfig(
         'syntax-highlighter.engine'),
       'preserve-linebreaks' => true,
     );
   }
 
 
   /**
    * @task engine
    */
   public static function newMarkupEngine(array $options) {
 
     $options += self::getMarkupEngineDefaultConfiguration();
 
     $engine = new PhutilRemarkupEngine();
 
     $engine->setConfig('preserve-linebreaks', $options['preserve-linebreaks']);
     $engine->setConfig('pygments.enabled', $options['pygments']);
     $engine->setConfig(
       'uri.allowed-protocols',
       $options['uri.allowed-protocols']);
     $engine->setConfig('differential.diff', $options['differential.diff']);
     $engine->setConfig('header.generate-toc', $options['header.generate-toc']);
     $engine->setConfig(
       'syntax-highlighter.engine',
       $options['syntax-highlighter.engine']);
 
     $rules = array();
     $rules[] = new PhutilRemarkupRuleEscapeRemarkup();
     $rules[] = new PhutilRemarkupRuleMonospace();
 
 
     $rules[] = new PhutilRemarkupRuleDocumentLink();
 
     if ($options['youtube']) {
       $rules[] = new PhabricatorRemarkupRuleYoutube();
     }
 
     $applications = PhabricatorApplication::getAllInstalledApplications();
     foreach ($applications as $application) {
       foreach ($application->getRemarkupRules() as $rule) {
         $rules[] = $rule;
       }
     }
 
     $rules[] = new PhutilRemarkupRuleHyperlink();
 
     if ($options['macros']) {
       $rules[] = new PhabricatorRemarkupRuleImageMacro();
       $rules[] = new PhabricatorRemarkupRuleMeme();
     }
 
     $rules[] = new PhutilRemarkupRuleBold();
     $rules[] = new PhutilRemarkupRuleItalic();
     $rules[] = new PhutilRemarkupRuleDel();
     $rules[] = new PhutilRemarkupRuleUnderline();
 
     foreach (self::loadCustomInlineRules() as $rule) {
       $rules[] = $rule;
     }
 
     $blocks = array();
     $blocks[] = new PhutilRemarkupEngineRemarkupQuotesBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupLiteralBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupHeaderBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupHorizontalRuleBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupListBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupCodeBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupNoteBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupTableBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupSimpleTableBlockRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupInterpreterRule();
     $blocks[] = new PhutilRemarkupEngineRemarkupDefaultBlockRule();
 
     foreach (self::loadCustomBlockRules() as $rule) {
       $blocks[] = $rule;
     }
 
     foreach ($blocks as $block) {
       $block->setMarkupRules($rules);
     }
 
     $engine->setBlockRules($blocks);
 
     return $engine;
   }
 
-  public static function extractPHIDsFromMentions(array $content_blocks) {
+  public static function extractPHIDsFromMentions(
+    PhabricatorUser $viewer,
+    array $content_blocks) {
+
     $mentions = array();
 
     $engine = self::newDifferentialMarkupEngine();
-    $engine->setConfig('viewer', PhabricatorUser::getOmnipotentUser());
+    $engine->setConfig('viewer', $viewer);
 
     foreach ($content_blocks as $content_block) {
       $engine->markupText($content_block);
       $phids = $engine->getTextMetadata(
         PhabricatorRemarkupRuleMention::KEY_MENTIONED,
         array());
       $mentions += $phids;
     }
 
     return $mentions;
   }
 
   public static function extractFilePHIDsFromEmbeddedFiles(
+    PhabricatorUser $viewer,
     array $content_blocks) {
     $files = array();
 
     $engine = self::newDifferentialMarkupEngine();
-    $engine->setConfig('viewer', PhabricatorUser::getOmnipotentUser());
+    $engine->setConfig('viewer', $viewer);
 
     foreach ($content_blocks as $content_block) {
       $engine->markupText($content_block);
       $ids = $engine->getTextMetadata(
         PhabricatorRemarkupRuleEmbedFile::KEY_EMBED_FILE_PHIDS,
         array());
       $files += $ids;
     }
 
     return $files;
   }
 
   /**
    * Produce a corpus summary, in a way that shortens the underlying text
    * without truncating it somewhere awkward.
    *
    * TODO: We could do a better job of this.
    *
    * @param string  Remarkup corpus to summarize.
    * @return string Summarized corpus.
    */
   public static function summarize($corpus) {
 
     // Major goals here are:
     //  - Don't split in the middle of a character (utf-8).
     //  - Don't split in the middle of, e.g., **bold** text, since
     //    we end up with hanging '**' in the summary.
     //  - Try not to pick an image macro, header, embedded file, etc.
     //  - Hopefully don't return too much text. We don't explicitly limit
     //    this right now.
 
     $blocks = preg_split("/\n *\n\s*/", trim($corpus));
 
     $best = null;
     foreach ($blocks as $block) {
       // This is a test for normal spaces in the block, i.e. a heuristic to
       // distinguish standard paragraphs from things like image macros. It may
       // not work well for non-latin text. We prefer to summarize with a
       // paragraph of normal words over an image macro, if possible.
       $has_space = preg_match('/\w\s\w/', $block);
 
       // This is a test to find embedded images and headers. We prefer to
       // summarize with a normal paragraph over a header or an embedded object,
       // if possible.
       $has_embed = preg_match('/^[{=]/', $block);
 
       if ($has_space && !$has_embed) {
         // This seems like a good summary, so return it.
         return $block;
       }
 
       if (!$best) {
         // This is the first block we found; if everything is garbage just
         // use the first block.
         $best = $block;
       }
     }
 
     return $best;
   }
 
   private static function loadCustomInlineRules() {
     return id(new PhutilSymbolLoader())
       ->setAncestorClass('PhabricatorRemarkupCustomInlineRule')
       ->loadObjects();
   }
 
   private static function loadCustomBlockRules() {
     return id(new PhutilSymbolLoader())
       ->setAncestorClass('PhabricatorRemarkupCustomBlockRule')
       ->loadObjects();
   }
 
 }