diff --git a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
index 1d7b646270..3eb1568a76 100644
--- a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
+++ b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
@@ -1,275 +1,282 @@
 <?php
 
 final class PhabricatorDifferentialConfigOptions
   extends PhabricatorApplicationConfigOptions {
 
   public function getName() {
     return pht('Differential');
   }
 
   public function getDescription() {
     return pht('Configure Differential code review.');
   }
 
   public function getIcon() {
     return 'fa-cog';
   }
 
   public function getGroup() {
     return 'apps';
   }
 
   public function getOptions() {
     $caches_href = PhabricatorEnv::getDoclink('Managing Caches');
 
     $custom_field_type = 'custom:PhabricatorCustomFieldConfigOptionType';
 
     $fields = array(
       new DifferentialNextStepField(),
 
       new DifferentialTitleField(),
       new DifferentialSummaryField(),
       new DifferentialTestPlanField(),
       new DifferentialAuthorField(),
       new DifferentialReviewersField(),
       new DifferentialProjectReviewersField(),
       new DifferentialReviewedByField(),
       new DifferentialSubscribersField(),
       new DifferentialRepositoryField(),
       new DifferentialProjectsField(),
       new DifferentialViewPolicyField(),
       new DifferentialEditPolicyField(),
 
       new DifferentialParentRevisionsField(),
       new DifferentialChildRevisionsField(),
       new DifferentialManiphestTasksField(),
       new DifferentialCommitsField(),
 
       new DifferentialJIRAIssuesField(),
       new DifferentialAsanaRepresentationField(),
 
       new DifferentialChangesSinceLastUpdateField(),
       new DifferentialBranchField(),
 
       new DifferentialBlameRevisionField(),
       new DifferentialPathField(),
       new DifferentialHostField(),
       new DifferentialLintField(),
       new DifferentialUnitField(),
       new DifferentialRevertPlanField(),
 
       new DifferentialApplyPatchField(),
 
       new DifferentialRevisionIDField(),
     );
 
     $default_fields = array();
     foreach ($fields as $field) {
       $default_fields[$field->getFieldKey()] = array(
         'disabled' => $field->shouldDisableByDefault(),
       );
     }
 
+    $inline_description = $this->deformat(
+      pht(<<<EOHELP
+To include patches inline in email bodies, set this option to a positive
+integer. Patches will be inlined if they are at most that many lines and at
+most 256 times that many bytes.
+
+For example, a value of 100 means "inline patches if they are at not more than
+100 lines long and not more than 25,600 bytes large".
+
+By default, patches are not inlined.
+EOHELP
+      ));
+
     return array(
       $this->newOption(
         'differential.fields',
         $custom_field_type,
         $default_fields)
         ->setCustomData(
           id(new DifferentialRevision())->getCustomFieldBaseClass())
         ->setDescription(
           pht(
             "Select and reorder revision fields.\n\n".
             "NOTE: This feature is under active development and subject ".
             "to change.")),
       $this->newOption(
         'differential.whitespace-matters',
         'list<regex>',
         array(
           '/\.py$/',
           '/\.l?hs$/',
         ))
         ->setDescription(
           pht(
             "List of file regexps where whitespace is meaningful and should ".
             "not use 'ignore-all' by default")),
       $this->newOption('differential.require-test-plan-field', 'bool', true)
         ->setBoolOptions(
           array(
             pht("Require 'Test Plan' field"),
             pht("Make 'Test Plan' field optional"),
           ))
         ->setSummary(pht('Require "Test Plan" field?'))
         ->setDescription(
           pht(
             "Differential has a required 'Test Plan' field by default. You ".
             "can make it optional by setting this to false. You can also ".
             "completely remove it above, if you prefer.")),
       $this->newOption('differential.enable-email-accept', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Enable Email "!accept" Action'),
             pht('Disable Email "!accept" Action'),
           ))
         ->setSummary(pht('Enable or disable "!accept" action via email.'))
         ->setDescription(
           pht(
             'If inbound email is configured, users can interact with '.
             'revisions by using "!actions" in email replies (for example, '.
             '"!resign" or "!rethink"). However, by default, users may not '.
             '"!accept" revisions via email: email authentication can be '.
             'configured to be very weak, and email "!accept" is kind of '.
             'sketchy and implies the revision may not actually be receiving '.
             'thorough review. You can enable "!accept" by setting this '.
             'option to true.')),
       $this->newOption('differential.generated-paths', 'list<regex>', array())
         ->setSummary(pht('File regexps to treat as automatically generated.'))
         ->setDescription(
           pht(
             'List of file regexps that should be treated as if they are '.
             'generated by an automatic process, and thus be hidden by '.
             'default in Differential.'.
             "\n\n".
             'NOTE: This property is cached, so you will need to purge the '.
             'cache after making changes if you want the new configuration '.
             'to affect existing revisions. For instructions, see '.
             '**[[ %s | Managing Caches ]]** in the documentation.',
             $caches_href))
         ->addExample("/config\.h$/\n#(^|/)autobuilt/#", pht('Valid Setting')),
       $this->newOption('differential.sticky-accept', 'bool', true)
         ->setBoolOptions(
           array(
             pht('Accepts persist across updates'),
             pht('Accepts are reset by updates'),
           ))
         ->setSummary(
           pht('Should "Accepted" revisions remain "Accepted" after updates?'))
         ->setDescription(
           pht(
             'Normally, when revisions that have been "Accepted" are updated, '.
             'they remain "Accepted". This allows reviewers to suggest minor '.
             'alterations when accepting, and encourages authors to update '.
             'if they make minor changes in response to this feedback.'.
             "\n\n".
             'If you want updates to always require re-review, you can disable '.
             'the "stickiness" of the "Accepted" status with this option. '.
             'This may make the process for minor changes much more burdensome '.
             'to both authors and reviewers.')),
       $this->newOption('differential.allow-self-accept', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Allow self-accept'),
             pht('Disallow self-accept'),
           ))
         ->setSummary(pht('Allows users to accept their own revisions.'))
         ->setDescription(
           pht(
             "If you set this to true, users can accept their own revisions. ".
             "This action is disabled by default because it's most likely not ".
             "a behavior you want, but it proves useful if you are working ".
             "alone on a project and want to make use of all of ".
             "differential's features.")),
       $this->newOption('differential.always-allow-close', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Allow any user'),
             pht('Restrict to submitter'),
           ))
         ->setSummary(pht('Allows any user to close accepted revisions.'))
         ->setDescription(
           pht(
             'If you set this to true, any user can close any revision so '.
             'long as it has been accepted. This can be useful depending on '.
             'your development model. For example, github-style pull requests '.
             'where the reviewer is often the actual committer can benefit '.
             'from turning this option to true. If false, only the submitter '.
             'can close a revision.')),
       $this->newOption('differential.always-allow-abandon', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Allow any user'),
             pht('Restrict to submitter'),
           ))
         ->setSummary(pht('Allows any user to abandon revisions.'))
         ->setDescription(
           pht(
             'If you set this to true, any user can abandon any revision. If '.
             'false, only the submitter can abandon a revision.')),
       $this->newOption('differential.allow-reopen', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Enable reopen'),
             pht('Disable reopen'),
           ))
         ->setSummary(pht('Allows any user to reopen a closed revision.'))
         ->setDescription(
           pht(
             'If you set this to true, any user can reopen a revision so '.
             'long as it has been closed. This can be useful if a revision '.
             'is accidentally closed or if a developer changes his or her '.
             'mind after closing a revision. If it is false, reopening '.
             'is not allowed.')),
       $this->newOption('differential.close-on-accept', 'bool', false)
         ->setBoolOptions(
           array(
             pht('Treat Accepted Revisions as "Closed"'),
             pht('Treat Accepted Revisions as "Open"'),
           ))
         ->setSummary(pht('Allows "Accepted" to act as a closed status.'))
         ->setDescription(
           pht(
             'Normally, Differential revisions remain on the dashboard when '.
             'they are "Accepted", and the author then commits the changes '.
             'to "Close" the revision and move it off the dashboard.'.
             "\n\n".
             'If you have an unusual workflow where Differential is used for '.
             'post-commit review (normally called "Audit", elsewhere in '.
             'Phabricator), you can set this flag to treat the "Accepted" '.
             'state as a "Closed" state and end the review workflow early.'.
             "\n\n".
             'This sort of workflow is very unusual. Very few installs should '.
             'need to change this option.')),
       $this->newOption(
         'metamta.differential.subject-prefix',
         'string',
         '[Differential]')
         ->setDescription(pht('Subject prefix for Differential mail.')),
       $this->newOption(
         'metamta.differential.attach-patches',
         'bool',
         false)
         ->setBoolOptions(
           array(
             pht('Attach Patches'),
             pht('Do Not Attach Patches'),
           ))
         ->setSummary(pht('Attach patches to email, as text attachments.'))
         ->setDescription(
           pht(
             'If you set this to true, Phabricator will attach patches to '.
             'Differential mail (as text attachments). This will not work if '.
             'you are using SendGrid as your mail adapter.')),
       $this->newOption(
         'metamta.differential.inline-patches',
         'int',
         0)
         ->setSummary(pht('Inline patches in email, as body text.'))
-        ->setDescription(
-          pht(
-            "To include patches inline in email bodies, set this to a ".
-            "positive integer. Patches will be inlined if they are at most ".
-            "that many lines. For instance, a value of 100 means 'inline ".
-            "patches if they are no longer than 100 lines'. By default, ".
-            "patches are not inlined.")),
+        ->setDescription($inline_description),
       $this->newOption(
         'metamta.differential.patch-format',
         'enum',
         'unified')
         ->setDescription(
           pht('Format for inlined or attached patches.'))
         ->setEnumOptions(
           array('unified' => 'unified', 'git' => 'git')),
     );
   }
 
 }
diff --git a/src/applications/differential/editor/DifferentialTransactionEditor.php b/src/applications/differential/editor/DifferentialTransactionEditor.php
index 3e9fe2b99f..b4828494c0 100644
--- a/src/applications/differential/editor/DifferentialTransactionEditor.php
+++ b/src/applications/differential/editor/DifferentialTransactionEditor.php
@@ -1,1906 +1,1925 @@
 <?php
 
 final class DifferentialTransactionEditor
   extends PhabricatorApplicationTransactionEditor {
 
   private $changedPriorToCommitURI;
   private $isCloseByCommit;
   private $repositoryPHIDOverride = false;
   private $didExpandInlineState = false;
   private $affectedPaths;
 
   public function getEditorApplicationClass() {
     return 'PhabricatorDifferentialApplication';
   }
 
   public function getEditorObjectsDescription() {
     return pht('Differential Revisions');
   }
 
   public function getDiffUpdateTransaction(array $xactions) {
     $type_update = DifferentialTransaction::TYPE_UPDATE;
 
     foreach ($xactions as $xaction) {
       if ($xaction->getTransactionType() == $type_update) {
         return $xaction;
       }
     }
 
     return null;
   }
 
   public function setIsCloseByCommit($is_close_by_commit) {
     $this->isCloseByCommit = $is_close_by_commit;
     return $this;
   }
 
   public function getIsCloseByCommit() {
     return $this->isCloseByCommit;
   }
 
   public function setChangedPriorToCommitURI($uri) {
     $this->changedPriorToCommitURI = $uri;
     return $this;
   }
 
   public function getChangedPriorToCommitURI() {
     return $this->changedPriorToCommitURI;
   }
 
   public function setRepositoryPHIDOverride($phid_or_null) {
     $this->repositoryPHIDOverride = $phid_or_null;
     return $this;
   }
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_COMMENT;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
 
     $types[] = DifferentialTransaction::TYPE_ACTION;
     $types[] = DifferentialTransaction::TYPE_INLINE;
     $types[] = DifferentialTransaction::TYPE_STATUS;
     $types[] = DifferentialTransaction::TYPE_UPDATE;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_ACTION:
         return null;
       case DifferentialTransaction::TYPE_INLINE:
         return null;
       case DifferentialTransaction::TYPE_UPDATE:
         if ($this->getIsNewObject()) {
           return null;
         } else {
           return $object->getActiveDiff()->getPHID();
         }
     }
 
     return parent::getCustomTransactionOldValue($object, $xaction);
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_ACTION:
       case DifferentialTransaction::TYPE_UPDATE:
         return $xaction->getNewValue();
       case DifferentialTransaction::TYPE_INLINE:
         return null;
     }
 
     return parent::getCustomTransactionNewValue($object, $xaction);
   }
 
   protected function transactionHasEffect(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $actor_phid = $this->getActingAsPHID();
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_INLINE:
         return $xaction->hasComment();
       case DifferentialTransaction::TYPE_ACTION:
         $status_closed = ArcanistDifferentialRevisionStatus::CLOSED;
         $status_abandoned = ArcanistDifferentialRevisionStatus::ABANDONED;
         $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
         $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
         $status_plan = ArcanistDifferentialRevisionStatus::CHANGES_PLANNED;
 
         $action_type = $xaction->getNewValue();
         switch ($action_type) {
           case DifferentialAction::ACTION_ACCEPT:
           case DifferentialAction::ACTION_REJECT:
             if ($action_type == DifferentialAction::ACTION_ACCEPT) {
               $new_status = DifferentialReviewerStatus::STATUS_ACCEPTED;
             } else {
               $new_status = DifferentialReviewerStatus::STATUS_REJECTED;
             }
 
             $actor = $this->getActor();
 
             // These transactions can cause effects in two ways: by altering the
             // status of an existing reviewer; or by adding the actor as a new
             // reviewer.
 
             $will_add_reviewer = true;
             foreach ($object->getReviewerStatus() as $reviewer) {
               if ($reviewer->hasAuthority($actor)) {
                 if ($reviewer->getStatus() != $new_status) {
                   return true;
                 }
               }
               if ($reviewer->getReviewerPHID() == $actor_phid) {
                 $will_add_reviwer = false;
               }
             }
 
             return $will_add_reviewer;
           case DifferentialAction::ACTION_CLOSE:
             return ($object->getStatus() != $status_closed);
           case DifferentialAction::ACTION_ABANDON:
             return ($object->getStatus() != $status_abandoned);
           case DifferentialAction::ACTION_RECLAIM:
             return ($object->getStatus() == $status_abandoned);
           case DifferentialAction::ACTION_REOPEN:
             return ($object->getStatus() == $status_closed);
           case DifferentialAction::ACTION_RETHINK:
             return ($object->getStatus() != $status_plan);
           case DifferentialAction::ACTION_REQUEST:
             return ($object->getStatus() != $status_review);
           case DifferentialAction::ACTION_RESIGN:
             foreach ($object->getReviewerStatus() as $reviewer) {
               if ($reviewer->getReviewerPHID() == $actor_phid) {
                 return true;
               }
             }
             return false;
           case DifferentialAction::ACTION_CLAIM:
             return ($actor_phid != $object->getAuthorPHID());
         }
     }
 
     return parent::transactionHasEffect($object, $xaction);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
     $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
     $status_plan = ArcanistDifferentialRevisionStatus::CHANGES_PLANNED;
     $status_abandoned = ArcanistDifferentialRevisionStatus::ABANDONED;
     $status_accepted = ArcanistDifferentialRevisionStatus::ACCEPTED;
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_INLINE:
         return;
       case DifferentialTransaction::TYPE_UPDATE:
         if (!$this->getIsCloseByCommit()) {
           switch ($object->getStatus()) {
             case $status_revision:
             case $status_plan:
             case $status_abandoned:
               $object->setStatus($status_review);
               break;
           }
         }
 
         $diff = $this->requireDiff($xaction->getNewValue());
 
         $object->setLineCount($diff->getLineCount());
         if ($this->repositoryPHIDOverride !== false) {
           $object->setRepositoryPHID($this->repositoryPHIDOverride);
         } else {
           $object->setRepositoryPHID($diff->getRepositoryPHID());
         }
         $object->attachActiveDiff($diff);
 
         // TODO: Update the `diffPHID` once we add that.
         return;
       case DifferentialTransaction::TYPE_ACTION:
         switch ($xaction->getNewValue()) {
           case DifferentialAction::ACTION_RESIGN:
           case DifferentialAction::ACTION_ACCEPT:
           case DifferentialAction::ACTION_REJECT:
             // These have no direct effects, and affect review status only
             // indirectly by altering reviewers with TYPE_EDGE transactions.
             return;
           case DifferentialAction::ACTION_ABANDON:
             $object->setStatus(ArcanistDifferentialRevisionStatus::ABANDONED);
             return;
           case DifferentialAction::ACTION_RETHINK:
             $object->setStatus($status_plan);
             return;
           case DifferentialAction::ACTION_RECLAIM:
             $object->setStatus($status_review);
             return;
           case DifferentialAction::ACTION_REOPEN:
             $object->setStatus($status_review);
             return;
           case DifferentialAction::ACTION_REQUEST:
             $object->setStatus($status_review);
             return;
           case DifferentialAction::ACTION_CLOSE:
             $old_status = $object->getStatus();
             $object->setStatus(ArcanistDifferentialRevisionStatus::CLOSED);
             $was_accepted = ($old_status == $status_accepted);
             $object->setProperty(
               DifferentialRevision::PROPERTY_CLOSED_FROM_ACCEPTED,
               $was_accepted);
             return;
           case DifferentialAction::ACTION_CLAIM:
             $object->setAuthorPHID($this->getActingAsPHID());
             return;
           default:
             throw new Exception(
               pht(
                 'Differential action "%s" is not a valid action!',
                 $xaction->getNewValue()));
         }
         break;
     }
 
     return parent::applyCustomInternalTransaction($object, $xaction);
   }
 
   protected function expandTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     $results = parent::expandTransaction($object, $xaction);
 
     $actor = $this->getActor();
     $actor_phid = $this->getActingAsPHID();
     $type_edge = PhabricatorTransactions::TYPE_EDGE;
 
     $status_plan = ArcanistDifferentialRevisionStatus::CHANGES_PLANNED;
 
     $edge_reviewer = DifferentialRevisionHasReviewerEdgeType::EDGECONST;
     $edge_ref_task = DifferentialRevisionHasTaskEdgeType::EDGECONST;
 
     $is_sticky_accept = PhabricatorEnv::getEnvConfig(
       'differential.sticky-accept');
 
     $downgrade_rejects = false;
     $downgrade_accepts = false;
     if ($this->getIsCloseByCommit()) {
       // Never downgrade reviewers when we're closing a revision after a
       // commit.
     } else {
       switch ($xaction->getTransactionType()) {
         case DifferentialTransaction::TYPE_UPDATE:
           $downgrade_rejects = true;
           if (!$is_sticky_accept) {
             // If "sticky accept" is disabled, also downgrade the accepts.
             $downgrade_accepts = true;
           }
           break;
         case DifferentialTransaction::TYPE_ACTION:
           switch ($xaction->getNewValue()) {
             case DifferentialAction::ACTION_REQUEST:
               $downgrade_rejects = true;
               if ((!$is_sticky_accept) ||
                   ($object->getStatus() != $status_plan)) {
                 // If the old state isn't "changes planned", downgrade the
                 // accepts. This exception allows an accepted revision to
                 // go through Plan Changes -> Request Review to return to
                 // "accepted" if the author didn't update the revision.
                 $downgrade_accepts = true;
               }
               break;
           }
           break;
       }
     }
 
     $new_accept = DifferentialReviewerStatus::STATUS_ACCEPTED;
     $new_reject = DifferentialReviewerStatus::STATUS_REJECTED;
     $old_accept = DifferentialReviewerStatus::STATUS_ACCEPTED_OLDER;
     $old_reject = DifferentialReviewerStatus::STATUS_REJECTED_OLDER;
 
     if ($downgrade_rejects || $downgrade_accepts) {
       // When a revision is updated, change all "reject" to "rejected older
       // revision". This means we won't immediately push the update back into
       // "needs review", but outstanding rejects will still block it from
       // moving to "accepted".
 
       // We also do this for "Request Review", even though the diff is not
       // updated directly. Essentially, this acts like an update which doesn't
       // actually change the diff text.
 
       $edits = array();
       foreach ($object->getReviewerStatus() as $reviewer) {
         if ($downgrade_rejects) {
           if ($reviewer->getStatus() == $new_reject) {
             $edits[$reviewer->getReviewerPHID()] = array(
               'data' => array(
                 'status' => $old_reject,
               ),
             );
           }
         }
 
         if ($downgrade_accepts) {
           if ($reviewer->getStatus() == $new_accept) {
             $edits[$reviewer->getReviewerPHID()] = array(
               'data' => array(
                 'status' => $old_accept,
               ),
             );
           }
         }
       }
 
       if ($edits) {
         $results[] = id(new DifferentialTransaction())
           ->setTransactionType($type_edge)
           ->setMetadataValue('edge:type', $edge_reviewer)
           ->setIgnoreOnNoEffect(true)
           ->setNewValue(array('+' => $edits));
       }
     }
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_UPDATE:
         if ($this->getIsCloseByCommit()) {
           // Don't bother with any of this if this update is a side effect of
           // commit detection.
           break;
         }
 
         // When a revision is updated and the diff comes from a branch named
         // "T123" or similar, automatically associate the commit with the
         // task that the branch names.
 
         $maniphest = 'PhabricatorManiphestApplication';
         if (PhabricatorApplication::isClassInstalled($maniphest)) {
           $diff = $this->requireDiff($xaction->getNewValue());
           $branch = $diff->getBranch();
 
           // No "$", to allow for branches like T123_demo.
           $match = null;
           if (preg_match('/^T(\d+)/i', $branch, $match)) {
             $task_id = $match[1];
             $tasks = id(new ManiphestTaskQuery())
               ->setViewer($this->getActor())
               ->withIDs(array($task_id))
               ->execute();
             if ($tasks) {
               $task = head($tasks);
               $task_phid = $task->getPHID();
 
               $results[] = id(new DifferentialTransaction())
                 ->setTransactionType($type_edge)
                 ->setMetadataValue('edge:type', $edge_ref_task)
                 ->setIgnoreOnNoEffect(true)
                 ->setNewValue(array('+' => array($task_phid => $task_phid)));
             }
           }
         }
         break;
 
       case PhabricatorTransactions::TYPE_COMMENT:
         // When a user leaves a comment, upgrade their reviewer status from
         // "added" to "commented" if they're also a reviewer. We may further
         // upgrade this based on other actions in the transaction group.
 
         $status_added = DifferentialReviewerStatus::STATUS_ADDED;
         $status_commented = DifferentialReviewerStatus::STATUS_COMMENTED;
 
         $data = array(
           'status' => $status_commented,
         );
 
         $edits = array();
         foreach ($object->getReviewerStatus() as $reviewer) {
           if ($reviewer->getReviewerPHID() == $actor_phid) {
             if ($reviewer->getStatus() == $status_added) {
               $edits[$actor_phid] = array(
                 'data' => $data,
               );
             }
           }
         }
 
         if ($edits) {
           $results[] = id(new DifferentialTransaction())
             ->setTransactionType($type_edge)
             ->setMetadataValue('edge:type', $edge_reviewer)
             ->setIgnoreOnNoEffect(true)
             ->setNewValue(array('+' => $edits));
         }
         break;
 
       case DifferentialTransaction::TYPE_ACTION:
         $action_type = $xaction->getNewValue();
 
         switch ($action_type) {
           case DifferentialAction::ACTION_ACCEPT:
           case DifferentialAction::ACTION_REJECT:
             if ($action_type == DifferentialAction::ACTION_ACCEPT) {
               $data = array(
                 'status' => DifferentialReviewerStatus::STATUS_ACCEPTED,
               );
             } else {
               $data = array(
                 'status' => DifferentialReviewerStatus::STATUS_REJECTED,
               );
             }
 
             $edits = array();
 
             foreach ($object->getReviewerStatus() as $reviewer) {
               if ($reviewer->hasAuthority($actor)) {
                 $edits[$reviewer->getReviewerPHID()] = array(
                   'data' => $data,
                 );
               }
             }
 
             // Also either update or add the actor themselves as a reviewer.
             $edits[$actor_phid] = array(
               'data' => $data,
             );
 
             $results[] = id(new DifferentialTransaction())
               ->setTransactionType($type_edge)
               ->setMetadataValue('edge:type', $edge_reviewer)
               ->setIgnoreOnNoEffect(true)
               ->setNewValue(array('+' => $edits));
             break;
 
           case DifferentialAction::ACTION_CLAIM:
             // If the user is commandeering, add the previous owner as a
             // reviewer and remove the actor.
 
             $edits = array(
               '-' => array(
                 $actor_phid => $actor_phid,
               ),
             );
 
             $owner_phid = $object->getAuthorPHID();
             if ($owner_phid) {
               $reviewer = new DifferentialReviewer(
                 $owner_phid,
                 array(
                   'status' => DifferentialReviewerStatus::STATUS_ADDED,
                 ));
 
               $edits['+'] = array(
                 $owner_phid => array(
                   'data' => $reviewer->getEdgeData(),
                 ),
               );
             }
 
             // NOTE: We're setting setIsCommandeerSideEffect() on this because
             // normally you can't add a revision's author as a reviewer, but
             // this action swaps them after validation executes.
 
             $results[] = id(new DifferentialTransaction())
               ->setTransactionType($type_edge)
               ->setMetadataValue('edge:type', $edge_reviewer)
               ->setIgnoreOnNoEffect(true)
               ->setIsCommandeerSideEffect(true)
               ->setNewValue($edits);
 
             break;
           case DifferentialAction::ACTION_RESIGN:
             // If the user is resigning, add a separate reviewer edit
             // transaction which removes them as a reviewer.
 
             $results[] = id(new DifferentialTransaction())
               ->setTransactionType($type_edge)
               ->setMetadataValue('edge:type', $edge_reviewer)
               ->setIgnoreOnNoEffect(true)
               ->setNewValue(
                 array(
                   '-' => array(
                     $actor_phid => $actor_phid,
                   ),
                 ));
 
             break;
         }
       break;
     }
 
     if (!$this->didExpandInlineState) {
       switch ($xaction->getTransactionType()) {
         case PhabricatorTransactions::TYPE_COMMENT:
         case DifferentialTransaction::TYPE_ACTION:
         case DifferentialTransaction::TYPE_UPDATE:
         case DifferentialTransaction::TYPE_INLINE:
           $this->didExpandInlineState = true;
 
           $actor_phid = $this->getActingAsPHID();
           $actor_is_author = ($object->getAuthorPHID() == $actor_phid);
           if (!$actor_is_author) {
             break;
           }
 
           $state_map = PhabricatorTransactions::getInlineStateMap();
 
           $inlines = id(new DifferentialDiffInlineCommentQuery())
             ->setViewer($this->getActor())
             ->withRevisionPHIDs(array($object->getPHID()))
             ->withFixedStates(array_keys($state_map))
             ->execute();
 
           if (!$inlines) {
             break;
           }
 
           $old_value = mpull($inlines, 'getFixedState', 'getPHID');
           $new_value = array();
           foreach ($old_value as $key => $state) {
             $new_value[$key] = $state_map[$state];
           }
 
           $results[] = id(new DifferentialTransaction())
             ->setTransactionType(PhabricatorTransactions::TYPE_INLINESTATE)
             ->setIgnoreOnNoEffect(true)
             ->setOldValue($old_value)
             ->setNewValue($new_value);
           break;
       }
     }
 
     return $results;
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case DifferentialTransaction::TYPE_ACTION:
         return;
       case DifferentialTransaction::TYPE_INLINE:
         $reply = $xaction->getComment()->getReplyToComment();
         if ($reply && !$reply->getHasReplies()) {
           $reply->setHasReplies(1)->save();
         }
         return;
       case DifferentialTransaction::TYPE_UPDATE:
         // Now that we're inside the transaction, do a final check.
         $diff = $this->requireDiff($xaction->getNewValue());
 
         // TODO: It would be slightly cleaner to just revalidate this
         // transaction somehow using the same validation code, but that's
         // not easy to do at the moment.
 
         $revision_id = $diff->getRevisionID();
         if ($revision_id && ($revision_id != $object->getID())) {
           throw new Exception(
             pht(
               'Diff is already attached to another revision. You lost '.
               'a race?'));
         }
 
         // TODO: This can race with diff updates, particularly those from
         // Harbormaster. See discussion in T8650.
         $diff->setRevisionID($object->getID());
         $diff->save();
 
         // Update Harbormaster to set the containerPHID correctly for any
         // existing buildables. We may otherwise have buildables stuck with
         // the old (`null`) container.
 
         // TODO: This is a bit iffy, maybe we can find a cleaner approach?
         // In particular, this could (rarely) be overwritten by Harbormaster
         // workers.
         $table = new HarbormasterBuildable();
         $conn_w = $table->establishConnection('w');
         queryfx(
           $conn_w,
           'UPDATE %T SET containerPHID = %s WHERE buildablePHID = %s',
           $table->getTableName(),
           $object->getPHID(),
           $diff->getPHID());
 
         return;
     }
 
     return parent::applyCustomExternalTransaction($object, $xaction);
   }
 
   protected function applyBuiltinExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_INLINESTATE:
         $table = new DifferentialTransactionComment();
         $conn_w = $table->establishConnection('w');
         foreach ($xaction->getNewValue() as $phid => $state) {
           queryfx(
             $conn_w,
             'UPDATE %T SET fixedState = %s WHERE phid = %s',
             $table->getTableName(),
             $state,
             $phid);
         }
         break;
     }
 
     return parent::applyBuiltinExternalTransaction($object, $xaction);
   }
 
   protected function mergeEdgeData($type, array $u, array $v) {
     $result = parent::mergeEdgeData($type, $u, $v);
 
     switch ($type) {
       case DifferentialRevisionHasReviewerEdgeType::EDGECONST:
         // When the same reviewer has their status updated by multiple
         // transactions, we want the strongest status to win. An example of
         // this is when a user adds a comment and also accepts a revision which
         // they are a reviewer on. The comment creates a "commented" status,
         // while the accept creates an "accepted" status. Since accept is
         // stronger, it should win and persist.
 
         $u_status = idx($u, 'status');
         $v_status = idx($v, 'status');
         $u_str = DifferentialReviewerStatus::getStatusStrength($u_status);
         $v_str = DifferentialReviewerStatus::getStatusStrength($v_status);
         if ($u_str > $v_str) {
           $result['status'] = $u_status;
         } else {
           $result['status'] = $v_status;
         }
         break;
     }
 
     return $result;
   }
 
   protected function applyFinalEffects(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     // Load the most up-to-date version of the revision and its reviewers,
     // so we don't need to try to deduce the state of reviewers by examining
     // all the changes made by the transactions. Then, update the reviewers
     // on the object to make sure we're acting on the current reviewer set
     // (and, for example, sending mail to the right people).
 
     $new_revision = id(new DifferentialRevisionQuery())
       ->setViewer($this->getActor())
       ->needReviewerStatus(true)
       ->needActiveDiffs(true)
       ->withIDs(array($object->getID()))
       ->executeOne();
     if (!$new_revision) {
       throw new Exception(
         pht('Failed to load revision from transaction finalization.'));
     }
 
     $object->attachReviewerStatus($new_revision->getReviewerStatus());
     $object->attachActiveDiff($new_revision->getActiveDiff());
     $object->attachRepository($new_revision->getRepository());
 
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case DifferentialTransaction::TYPE_UPDATE:
           $diff = $this->requireDiff($xaction->getNewValue(), true);
 
           // Update these denormalized index tables when we attach a new
           // diff to a revision.
 
           $this->updateRevisionHashTable($object, $diff);
           $this->updateAffectedPathTable($object, $diff);
           break;
       }
     }
 
     $status_accepted = ArcanistDifferentialRevisionStatus::ACCEPTED;
     $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
     $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
 
     $old_status = $object->getStatus();
     switch ($old_status) {
       case $status_accepted:
       case $status_revision:
       case $status_review:
         // Try to move a revision to "accepted". We look for:
         //
         //   - at least one accepting reviewer who is a user; and
         //   - no rejects; and
         //   - no rejects of older diffs; and
         //   - no blocking reviewers.
 
         $has_accepting_user = false;
         $has_rejecting_reviewer = false;
         $has_rejecting_older_reviewer = false;
         $has_blocking_reviewer = false;
         foreach ($object->getReviewerStatus() as $reviewer) {
           $reviewer_status = $reviewer->getStatus();
           switch ($reviewer_status) {
             case DifferentialReviewerStatus::STATUS_REJECTED:
               $has_rejecting_reviewer = true;
               break;
             case DifferentialReviewerStatus::STATUS_REJECTED_OLDER:
               $has_rejecting_older_reviewer = true;
               break;
             case DifferentialReviewerStatus::STATUS_BLOCKING:
               $has_blocking_reviewer = true;
               break;
             case DifferentialReviewerStatus::STATUS_ACCEPTED:
               if ($reviewer->isUser()) {
                 $has_accepting_user = true;
               }
               break;
           }
         }
 
         $new_status = null;
         if ($has_accepting_user &&
             !$has_rejecting_reviewer &&
             !$has_rejecting_older_reviewer &&
             !$has_blocking_reviewer) {
           $new_status = $status_accepted;
         } else if ($has_rejecting_reviewer) {
           // This isn't accepted, and there's at least one rejecting reviewer,
           // so the revision needs changes. This usually happens after a
           // "reject".
           $new_status = $status_revision;
         } else if ($old_status == $status_accepted) {
           // This revision was accepted, but it no longer satisfies the
           // conditions for acceptance. This usually happens after an accepting
           // reviewer resigns or is removed.
           $new_status = $status_review;
         }
 
         if ($new_status !== null && ($new_status != $old_status)) {
           $xaction = id(new DifferentialTransaction())
             ->setTransactionType(DifferentialTransaction::TYPE_STATUS)
             ->setOldValue($old_status)
             ->setNewValue($new_status);
 
           $xaction = $this->populateTransaction($object, $xaction)->save();
 
           $xactions[] = $xaction;
 
           $object->setStatus($new_status)->save();
         }
         break;
       default:
         // Revisions can't transition out of other statuses (like closed or
         // abandoned) as a side effect of reviewer status changes.
         break;
     }
 
     return $xactions;
   }
 
   protected function validateTransaction(
     PhabricatorLiskDAO $object,
     $type,
     array $xactions) {
 
     $errors = parent::validateTransaction($object, $type, $xactions);
 
     $config_self_accept_key = 'differential.allow-self-accept';
     $allow_self_accept = PhabricatorEnv::getEnvConfig($config_self_accept_key);
 
     foreach ($xactions as $xaction) {
       switch ($type) {
         case PhabricatorTransactions::TYPE_EDGE:
           switch ($xaction->getMetadataValue('edge:type')) {
             case DifferentialRevisionHasReviewerEdgeType::EDGECONST:
 
               // Prevent the author from becoming a reviewer.
 
               // NOTE: This is pretty gross, but this restriction is unusual.
               // If we end up with too much more of this, we should try to clean
               // this up -- maybe by moving validation to after transactions
               // are adjusted (so we can just examine the final value) or adding
               // a second phase there?
 
               $author_phid = $object->getAuthorPHID();
               $new = $xaction->getNewValue();
 
               $add = idx($new, '+', array());
               $eq = idx($new, '=', array());
               $phids = array_keys($add + $eq);
 
               foreach ($phids as $phid) {
                 if (($phid == $author_phid) &&
                     !$allow_self_accept &&
                     !$xaction->getIsCommandeerSideEffect()) {
                   $errors[] =
                     new PhabricatorApplicationTransactionValidationError(
                       $type,
                       pht('Invalid'),
                       pht('The author of a revision can not be a reviewer.'),
                       $xaction);
                 }
               }
               break;
           }
           break;
         case DifferentialTransaction::TYPE_UPDATE:
           $diff = $this->loadDiff($xaction->getNewValue());
           if (!$diff) {
             $errors[] = new PhabricatorApplicationTransactionValidationError(
               $type,
               pht('Invalid'),
               pht('The specified diff does not exist.'),
               $xaction);
           } else if (($diff->getRevisionID()) &&
             ($diff->getRevisionID() != $object->getID())) {
             $errors[] = new PhabricatorApplicationTransactionValidationError(
               $type,
               pht('Invalid'),
               pht(
                 'You can not update this revision to the specified diff, '.
                 'because the diff is already attached to another revision.'),
               $xaction);
           }
           break;
         case DifferentialTransaction::TYPE_ACTION:
           $error = $this->validateDifferentialAction(
             $object,
             $type,
             $xaction,
             $xaction->getNewValue());
           if ($error) {
             $errors[] = new PhabricatorApplicationTransactionValidationError(
               $type,
               pht('Invalid'),
               $error,
               $xaction);
           }
           break;
       }
     }
 
     return $errors;
   }
 
   private function validateDifferentialAction(
     DifferentialRevision $revision,
     $type,
     DifferentialTransaction $xaction,
     $action) {
 
     $author_phid = $revision->getAuthorPHID();
     $actor_phid = $this->getActingAsPHID();
     $actor_is_author = ($author_phid == $actor_phid);
 
     $config_abandon_key = 'differential.always-allow-abandon';
     $always_allow_abandon = PhabricatorEnv::getEnvConfig($config_abandon_key);
 
     $config_close_key = 'differential.always-allow-close';
     $always_allow_close = PhabricatorEnv::getEnvConfig($config_close_key);
 
     $config_reopen_key = 'differential.allow-reopen';
     $allow_reopen = PhabricatorEnv::getEnvConfig($config_reopen_key);
 
     $config_self_accept_key = 'differential.allow-self-accept';
     $allow_self_accept = PhabricatorEnv::getEnvConfig($config_self_accept_key);
 
     $revision_status = $revision->getStatus();
 
     $status_accepted = ArcanistDifferentialRevisionStatus::ACCEPTED;
     $status_abandoned = ArcanistDifferentialRevisionStatus::ABANDONED;
     $status_closed = ArcanistDifferentialRevisionStatus::CLOSED;
 
     switch ($action) {
       case DifferentialAction::ACTION_ACCEPT:
         if ($actor_is_author && !$allow_self_accept) {
           return pht(
             'You can not accept this revision because you are the owner.');
         }
 
         if ($revision_status == $status_abandoned) {
           return pht(
             'You can not accept this revision because it has been '.
             'abandoned.');
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             'You can not accept this revision because it has already been '.
             'closed.');
         }
 
         // TODO: It would be nice to make this generic at some point.
         $signatures = DifferentialRequiredSignaturesField::loadForRevision(
           $revision);
         foreach ($signatures as $phid => $signed) {
           if (!$signed) {
             return pht(
               'You can not accept this revision because the author has '.
               'not signed all of the required legal documents.');
           }
         }
 
         break;
 
       case DifferentialAction::ACTION_REJECT:
         if ($actor_is_author) {
           return pht('You can not request changes to your own revision.');
         }
 
         if ($revision_status == $status_abandoned) {
           return pht(
             'You can not request changes to this revision because it has been '.
             'abandoned.');
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             'You can not request changes to this revision because it has '.
             'already been closed.');
         }
         break;
 
       case DifferentialAction::ACTION_RESIGN:
         // You can always resign from a revision if you're a reviewer. If you
         // aren't, this is a no-op rather than invalid.
         break;
 
       case DifferentialAction::ACTION_CLAIM:
         // You can claim a revision if you're not the owner. If you are, this
         // is a no-op rather than invalid.
 
         if ($revision_status == $status_closed) {
           return pht(
             'You can not commandeer this revision because it has already been '.
             'closed.');
         }
         break;
 
       case DifferentialAction::ACTION_ABANDON:
         if (!$actor_is_author && !$always_allow_abandon) {
           return pht(
             'You can not abandon this revision because you do not own it. '.
             'You can only abandon revisions you own.');
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             'You can not abandon this revision because it has already been '.
             'closed.');
         }
 
         // NOTE: Abandons of already-abandoned revisions are treated as no-op
         // instead of invalid. Other abandons are OK.
 
         break;
 
       case DifferentialAction::ACTION_RECLAIM:
         if (!$actor_is_author) {
           return pht(
             'You can not reclaim this revision because you do not own '.
             'it. You can only reclaim revisions you own.');
         }
 
         if ($revision_status == $status_closed) {
           return pht(
             'You can not reclaim this revision because it has already been '.
             'closed.');
         }
 
         // NOTE: Reclaims of other non-abandoned revisions are treated as no-op
         // instead of invalid.
 
         break;
 
       case DifferentialAction::ACTION_REOPEN:
         if (!$allow_reopen) {
           return pht(
             'The reopen action is not enabled on this Phabricator install. '.
             'Adjust your configuration to enable it.');
         }
 
         // NOTE: If the revision is not closed, this is caught as a no-op
         // instead of an invalid transaction.
 
         break;
 
       case DifferentialAction::ACTION_RETHINK:
         if (!$actor_is_author) {
           return pht(
             'You can not plan changes to this revision because you do not '.
             'own it. To plan changes to a revision, you must be its owner.');
         }
 
         switch ($revision_status) {
           case ArcanistDifferentialRevisionStatus::ACCEPTED:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVISION:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVIEW:
             // These are OK.
             break;
           case ArcanistDifferentialRevisionStatus::CHANGES_PLANNED:
             // Let this through, it's a no-op.
             break;
           case ArcanistDifferentialRevisionStatus::ABANDONED:
             return pht(
               'You can not plan changes to this revision because it has '.
               'been abandoned.');
           case ArcanistDifferentialRevisionStatus::CLOSED:
             return pht(
               'You can not plan changes to this revision because it has '.
               'already been closed.');
           default:
             throw new Exception(
               pht(
                 'Encountered unexpected revision status ("%s") when '.
                 'validating "%s" action.',
                 $revision_status,
                 $action));
         }
         break;
 
       case DifferentialAction::ACTION_REQUEST:
         if (!$actor_is_author) {
           return pht(
             'You can not request review of this revision because you do '.
             'not own it. To request review of a revision, you must be its '.
             'owner.');
         }
 
         switch ($revision_status) {
           case ArcanistDifferentialRevisionStatus::ACCEPTED:
           case ArcanistDifferentialRevisionStatus::NEEDS_REVISION:
           case ArcanistDifferentialRevisionStatus::CHANGES_PLANNED:
             // These are OK.
             break;
           case ArcanistDifferentialRevisionStatus::NEEDS_REVIEW:
             // This will be caught as "no effect" later on.
             break;
           case ArcanistDifferentialRevisionStatus::ABANDONED:
             return pht(
               'You can not request review of this revision because it has '.
               'been abandoned. Instead, reclaim it.');
           case ArcanistDifferentialRevisionStatus::CLOSED:
             return pht(
               'You can not request review of this revision because it has '.
               'already been closed.');
           default:
             throw new Exception(
               pht(
                 'Encountered unexpected revision status ("%s") when '.
                 'validating "%s" action.',
                 $revision_status,
                 $action));
         }
         break;
 
       case DifferentialAction::ACTION_CLOSE:
         // We force revisions closed when we discover a corresponding commit.
         // In this case, revisions are allowed to transition to closed from
         // any state. This is an automated action taken by the daemons.
 
         if (!$this->getIsCloseByCommit()) {
           if (!$actor_is_author && !$always_allow_close) {
             return pht(
               'You can not close this revision because you do not own it. To '.
               'close a revision, you must be its owner.');
           }
 
           if ($revision_status != $status_accepted) {
             return pht(
               'You can not close this revision because it has not been '.
               'accepted. You can only close accepted revisions.');
           }
         }
         break;
     }
 
     return null;
   }
 
   protected function sortTransactions(array $xactions) {
     $xactions = parent::sortTransactions($xactions);
 
     $head = array();
     $tail = array();
 
     foreach ($xactions as $xaction) {
       $type = $xaction->getTransactionType();
       if ($type == DifferentialTransaction::TYPE_INLINE) {
         $tail[] = $xaction;
       } else {
         $head[] = $xaction;
       }
     }
 
     return array_values(array_merge($head, $tail));
   }
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {}
 
     return parent::requireCapabilities($object, $xaction);
   }
 
   protected function shouldPublishFeedStory(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function shouldSendMail(
     PhabricatorLiskDAO $object,
     array $xactions) {
     return true;
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
     $phids = array();
     $phids[] = $object->getAuthorPHID();
     foreach ($object->getReviewerStatus() as $reviewer) {
       $phids[] = $reviewer->getReviewerPHID();
     }
     return $phids;
   }
 
   protected function getMailAction(
     PhabricatorLiskDAO $object,
     array $xactions) {
     $action = parent::getMailAction($object, $xactions);
 
     $strongest = $this->getStrongestAction($object, $xactions);
     switch ($strongest->getTransactionType()) {
       case DifferentialTransaction::TYPE_UPDATE:
         $count = new PhutilNumber($object->getLineCount());
         $action = pht('%s, %s line(s)', $action, $count);
         break;
     }
 
     return $action;
   }
 
   protected function getMailSubjectPrefix() {
     return PhabricatorEnv::getEnvConfig('metamta.differential.subject-prefix');
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
     // This is nonstandard, but retains threading with older messages.
     $phid = $object->getPHID();
     return "differential-rev-{$phid}-req";
   }
 
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new DifferentialReplyHandler())
       ->setMailReceiver($object);
   }
 
   protected function buildMailTemplate(PhabricatorLiskDAO $object) {
     $id = $object->getID();
     $title = $object->getTitle();
 
     $original_title = $object->getOriginalTitle();
 
     $subject = "D{$id}: {$title}";
     $thread_topic = "D{$id}: {$original_title}";
 
     return id(new PhabricatorMetaMTAMail())
       ->setSubject($subject)
       ->addHeader('Thread-Topic', $thread_topic);
   }
 
   protected function buildMailBody(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $body = new PhabricatorMetaMTAMailBody();
     $body->setViewer($this->requireActor());
 
     $revision_uri = PhabricatorEnv::getProductionURI('/D'.$object->getID());
 
     $this->addHeadersAndCommentsToMailBody(
       $body,
       $xactions,
       pht('View Revision'),
       $revision_uri);
 
     $type_inline = DifferentialTransaction::TYPE_INLINE;
 
     $inlines = array();
     foreach ($xactions as $xaction) {
       if ($xaction->getTransactionType() == $type_inline) {
         $inlines[] = $xaction;
       }
     }
 
     if ($inlines) {
       $this->appendInlineCommentsForMail($object, $inlines, $body);
     }
 
     $changed_uri = $this->getChangedPriorToCommitURI();
     if ($changed_uri) {
       $body->addLinkSection(
         pht('CHANGED PRIOR TO COMMIT'),
         $changed_uri);
     }
 
     $this->addCustomFieldsToMailBody($body, $object, $xactions);
 
     $body->addLinkSection(
       pht('REVISION DETAIL'),
       $revision_uri);
 
     $update_xaction = null;
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case DifferentialTransaction::TYPE_UPDATE:
           $update_xaction = $xaction;
           break;
       }
     }
 
     if ($update_xaction) {
       $diff = $this->requireDiff($update_xaction->getNewValue(), true);
 
       $body->addTextSection(
         pht('AFFECTED FILES'),
         $this->renderAffectedFilesForMail($diff));
 
       $config_key_inline = 'metamta.differential.inline-patches';
       $config_inline = PhabricatorEnv::getEnvConfig($config_key_inline);
 
       $config_key_attach = 'metamta.differential.attach-patches';
       $config_attach = PhabricatorEnv::getEnvConfig($config_key_attach);
 
       if ($config_inline || $config_attach) {
-        $patch = $this->buildPatchForMail($diff);
-        $lines = substr_count($patch, "\n");
+        $body_limit = PhabricatorEnv::getEnvConfig('metamta.email-body-limit');
 
-        if ($config_inline && ($lines <= $config_inline)) {
-          $this->appendChangeDetailsForMail($object, $diff, $patch, $body);
+        $patch = $this->buildPatchForMail($diff);
+        if ($config_inline) {
+          $lines = substr_count($patch, "\n");
+          $bytes = strlen($patch);
+
+          // Limit the patch size to the smaller of 256 bytes per line or
+          // the mail body limit. This prevents degenerate behavior for patches
+          // with one line that is 10MB long. See T11748.
+          $byte_limits = array();
+          $byte_limits[] = (256 * $config_inline);
+          $byte_limits[] = $body_limit;
+          $byte_limit = min($byte_limits);
+
+          $lines_ok = ($lines <= $config_inline);
+          $bytes_ok = ($bytes <= $byte_limit);
+
+          if ($lines_ok && $bytes_ok) {
+            $this->appendChangeDetailsForMail($object, $diff, $patch, $body);
+          } else {
+            // TODO: Provide a helpful message about the patch being too
+            // large or lengthy here.
+          }
         }
 
         if ($config_attach) {
           $name = pht('D%s.%s.patch', $object->getID(), $diff->getID());
           $mime_type = 'text/x-patch; charset=utf-8';
           $body->addAttachment(
             new PhabricatorMetaMTAAttachment($patch, $name, $mime_type));
         }
       }
     }
 
     return $body;
   }
 
   public function getMailTagsMap() {
     return array(
       DifferentialTransaction::MAILTAG_REVIEW_REQUEST =>
         pht('A revision is created.'),
       DifferentialTransaction::MAILTAG_UPDATED =>
         pht('A revision is updated.'),
       DifferentialTransaction::MAILTAG_COMMENT =>
         pht('Someone comments on a revision.'),
       DifferentialTransaction::MAILTAG_CLOSED =>
         pht('A revision is closed.'),
       DifferentialTransaction::MAILTAG_REVIEWERS =>
         pht("A revision's reviewers change."),
       DifferentialTransaction::MAILTAG_CC =>
         pht("A revision's CCs change."),
       DifferentialTransaction::MAILTAG_OTHER =>
         pht('Other revision activity not listed above occurs.'),
     );
   }
 
   protected function supportsSearch() {
     return true;
   }
 
   protected function expandCustomRemarkupBlockTransactions(
     PhabricatorLiskDAO $object,
     array $xactions,
     array $changes,
     PhutilMarkupEngine $engine) {
 
     $flat_blocks = mpull($changes, 'getNewValue');
     $huge_block = implode("\n\n", $flat_blocks);
 
     $task_map = array();
     $task_refs = id(new ManiphestCustomFieldStatusParser())
       ->parseCorpus($huge_block);
     foreach ($task_refs as $match) {
       foreach ($match['monograms'] as $monogram) {
         $task_id = (int)trim($monogram, 'tT');
         $task_map[$task_id] = true;
       }
     }
 
     $rev_map = array();
     $rev_refs = id(new DifferentialCustomFieldDependsOnParser())
       ->parseCorpus($huge_block);
     foreach ($rev_refs as $match) {
       foreach ($match['monograms'] as $monogram) {
         $rev_id = (int)trim($monogram, 'dD');
         $rev_map[$rev_id] = true;
       }
     }
 
     $edges = array();
     $task_phids = array();
     $rev_phids = array();
 
     if ($task_map) {
       $tasks = id(new ManiphestTaskQuery())
         ->setViewer($this->getActor())
         ->withIDs(array_keys($task_map))
         ->execute();
 
       if ($tasks) {
         $task_phids = mpull($tasks, 'getPHID', 'getPHID');
         $edge_related = DifferentialRevisionHasTaskEdgeType::EDGECONST;
         $edges[$edge_related] = $task_phids;
       }
     }
 
     if ($rev_map) {
       $revs = id(new DifferentialRevisionQuery())
         ->setViewer($this->getActor())
         ->withIDs(array_keys($rev_map))
         ->execute();
       $rev_phids = mpull($revs, 'getPHID', 'getPHID');
 
       // NOTE: Skip any write attempts if a user cleverly implies a revision
       // depends upon itself.
       unset($rev_phids[$object->getPHID()]);
 
       if ($revs) {
         $depends = DifferentialRevisionDependsOnRevisionEdgeType::EDGECONST;
         $edges[$depends] = $rev_phids;
       }
     }
 
     $this->setUnmentionablePHIDMap(array_merge($task_phids, $rev_phids));
 
     $result = array();
     foreach ($edges as $type => $specs) {
       $result[] = id(new DifferentialTransaction())
         ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
         ->setMetadataValue('edge:type', $type)
         ->setNewValue(array('+' => $specs));
     }
 
     return $result;
   }
 
   private function appendInlineCommentsForMail(
     PhabricatorLiskDAO $object,
     array $inlines,
     PhabricatorMetaMTAMailBody $body) {
 
     $section = id(new DifferentialInlineCommentMailView())
       ->setViewer($this->getActor())
       ->setInlines($inlines)
       ->buildMailSection();
 
     $header = pht('INLINE COMMENTS');
 
     $section_text = "\n".$section->getPlaintext();
 
     $style = array(
       'margin: 6px 0 12px 0;',
     );
 
     $section_html = phutil_tag(
       'div',
       array(
         'style' => implode(' ', $style),
       ),
       $section->getHTML());
 
     $body->addPlaintextSection($header, $section_text, false);
     $body->addHTMLSection($header, $section_html);
   }
 
   private function appendChangeDetailsForMail(
     PhabricatorLiskDAO $object,
     DifferentialDiff $diff,
     $patch,
     PhabricatorMetaMTAMailBody $body) {
 
     $section = id(new DifferentialChangeDetailMailView())
       ->setViewer($this->getActor())
       ->setDiff($diff)
       ->setPatch($patch)
       ->buildMailSection();
 
     $header = pht('CHANGE DETAILS');
 
     $section_text = "\n".$section->getPlaintext();
 
     $style = array(
       'margin: 6px 0 12px 0;',
     );
 
     $section_html = phutil_tag(
       'div',
       array(
         'style' => implode(' ', $style),
       ),
       $section->getHTML());
 
     $body->addPlaintextSection($header, $section_text, false);
     $body->addHTMLSection($header, $section_html);
   }
 
   private function loadDiff($phid, $need_changesets = false) {
     $query = id(new DifferentialDiffQuery())
       ->withPHIDs(array($phid))
       ->setViewer($this->getActor());
 
     if ($need_changesets) {
       $query->needChangesets(true);
     }
 
     return $query->executeOne();
   }
 
   private function requireDiff($phid, $need_changesets = false) {
     $diff = $this->loadDiff($phid, $need_changesets);
     if (!$diff) {
       throw new Exception(pht('Diff "%s" does not exist!', $phid));
     }
 
     return $diff;
   }
 
 /* -(  Herald Integration  )------------------------------------------------- */
 
   protected function shouldApplyHeraldRules(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     if ($this->getIsNewObject()) {
       return true;
     }
 
     foreach ($xactions as $xaction) {
       switch ($xaction->getTransactionType()) {
         case DifferentialTransaction::TYPE_UPDATE:
           if (!$this->getIsCloseByCommit()) {
             return true;
           }
           break;
         case DifferentialTransaction::TYPE_ACTION:
           switch ($xaction->getNewValue()) {
             case DifferentialAction::ACTION_CLAIM:
               // When users commandeer revisions, we may need to trigger
               // signatures or author-based rules.
               return true;
           }
           break;
       }
     }
 
     return parent::shouldApplyHeraldRules($object, $xactions);
   }
 
   protected function didApplyHeraldRules(
     PhabricatorLiskDAO $object,
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
 
     $repository = $object->getRepository();
     if (!$repository) {
       return array();
     }
 
     if (!$this->affectedPaths) {
       return array();
     }
 
     $packages = PhabricatorOwnersPackage::loadAffectedPackages(
       $repository,
       $this->affectedPaths);
     if (!$packages) {
       return array();
     }
 
     // Remove packages that the revision author is an owner of. If you own
     // code, you don't need another owner to review it.
     $authority = id(new PhabricatorOwnersPackageQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withPHIDs(mpull($packages, 'getPHID'))
       ->withAuthorityPHIDs(array($object->getAuthorPHID()))
       ->execute();
     $authority = mpull($authority, null, 'getPHID');
 
     foreach ($packages as $key => $package) {
       $package_phid = $package->getPHID();
       if (isset($authority[$package_phid])) {
         unset($packages[$key]);
         continue;
       }
     }
 
     if (!$packages) {
       return array();
     }
 
     $auto_subscribe = array();
     $auto_review = array();
     $auto_block = array();
 
     foreach ($packages as $package) {
       switch ($package->getAutoReview()) {
         case PhabricatorOwnersPackage::AUTOREVIEW_SUBSCRIBE:
           $auto_subscribe[] = $package;
           break;
         case PhabricatorOwnersPackage::AUTOREVIEW_REVIEW:
           $auto_review[] = $package;
           break;
         case PhabricatorOwnersPackage::AUTOREVIEW_BLOCK:
           $auto_block[] = $package;
           break;
         case PhabricatorOwnersPackage::AUTOREVIEW_NONE:
         default:
           break;
       }
     }
 
     $owners_phid = id(new PhabricatorOwnersApplication())
       ->getPHID();
 
     $xactions = array();
     if ($auto_subscribe) {
       $xactions[] = $object->getApplicationTransactionTemplate()
         ->setAuthorPHID($owners_phid)
         ->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS)
         ->setNewValue(
           array(
             '+' => mpull($auto_subscribe, 'getPHID'),
           ));
     }
 
     $specs = array(
       array($auto_review, false),
       array($auto_block, true),
     );
 
     foreach ($specs as $spec) {
       list($reviewers, $blocking) = $spec;
       if (!$reviewers) {
         continue;
       }
 
       $phids = mpull($reviewers, 'getPHID');
       $xaction = $this->newAutoReviewTransaction($object, $phids, $blocking);
       if ($xaction) {
         $xactions[] = $xaction;
       }
     }
 
     return $xactions;
   }
 
   private function newAutoReviewTransaction(
     PhabricatorLiskDAO $object,
     array $phids,
     $is_blocking) {
 
     // TODO: This is substantially similar to DifferentialReviewersHeraldAction
     // and both are needlessly complex. This logic should live in the normal
     // transaction application pipeline. See T10967.
 
     $reviewers = $object->getReviewerStatus();
     $reviewers = mpull($reviewers, null, 'getReviewerPHID');
 
     if ($is_blocking) {
       $new_status = DifferentialReviewerStatus::STATUS_BLOCKING;
     } else {
       $new_status = DifferentialReviewerStatus::STATUS_ADDED;
     }
 
     $new_strength = DifferentialReviewerStatus::getStatusStrength(
       $new_status);
 
     $current = array();
     foreach ($phids as $phid) {
       if (!isset($reviewers[$phid])) {
         continue;
       }
 
       // If we're applying a stronger status (usually, upgrading a reviewer
       // into a blocking reviewer), skip this check so we apply the change.
       $old_strength = DifferentialReviewerStatus::getStatusStrength(
         $reviewers[$phid]->getStatus());
       if ($old_strength <= $new_strength) {
         continue;
       }
 
       $current[] = $phid;
     }
 
     $phids = array_diff($phids, $current);
 
     if (!$phids) {
       return null;
     }
 
     $phids = array_fuse($phids);
 
     $value = array();
     foreach ($phids as $phid) {
       $value[$phid] = array(
         'data' => array(
           'status' => $new_status,
         ),
       );
     }
 
     $edgetype_reviewer = DifferentialRevisionHasReviewerEdgeType::EDGECONST;
 
     $owners_phid = id(new PhabricatorOwnersApplication())
       ->getPHID();
 
     return $object->getApplicationTransactionTemplate()
       ->setAuthorPHID($owners_phid)
       ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
       ->setMetadataValue('edge:type', $edgetype_reviewer)
       ->setNewValue(
         array(
           '+' => $value,
         ));
   }
 
   protected function buildHeraldAdapter(
     PhabricatorLiskDAO $object,
     array $xactions) {
 
     $revision = id(new DifferentialRevisionQuery())
       ->setViewer($this->getActor())
       ->withPHIDs(array($object->getPHID()))
       ->needActiveDiffs(true)
       ->needReviewerStatus(true)
       ->executeOne();
     if (!$revision) {
       throw new Exception(
         pht('Failed to load revision for Herald adapter construction!'));
     }
 
     $adapter = HeraldDifferentialRevisionAdapter::newLegacyAdapter(
       $revision,
       $revision->getActiveDiff());
 
     return $adapter;
   }
 
   /**
    * Update the table which links Differential revisions to paths they affect,
    * so Diffusion can efficiently find pending revisions for a given file.
    */
   private function updateAffectedPathTable(
     DifferentialRevision $revision,
     DifferentialDiff $diff) {
 
     $repository = $revision->getRepository();
     if (!$repository) {
       // The repository where the code lives is untracked.
       return;
     }
 
     $path_prefix = null;
 
     $local_root = $diff->getSourceControlPath();
     if ($local_root) {
       // We're in a working copy which supports subdirectory checkouts (e.g.,
       // SVN) so we need to figure out what prefix we should add to each path
       // (e.g., trunk/projects/example/) to get the absolute path from the
       // root of the repository. DVCS systems like Git and Mercurial are not
       // affected.
 
       // Normalize both paths and check if the repository root is a prefix of
       // the local root. If so, throw it away. Note that this correctly handles
       // the case where the remote path is "/".
       $local_root = id(new PhutilURI($local_root))->getPath();
       $local_root = rtrim($local_root, '/');
 
       $repo_root = id(new PhutilURI($repository->getRemoteURI()))->getPath();
       $repo_root = rtrim($repo_root, '/');
 
       if (!strncmp($repo_root, $local_root, strlen($repo_root))) {
         $path_prefix = substr($local_root, strlen($repo_root));
       }
     }
 
     $changesets = $diff->getChangesets();
     $paths = array();
     foreach ($changesets as $changeset) {
       $paths[] = $path_prefix.'/'.$changeset->getFilename();
     }
 
     // Save the affected paths; we'll use them later to query Owners. This
     // uses the un-expanded paths.
     $this->affectedPaths = $paths;
 
     // Mark this as also touching all parent paths, so you can see all pending
     // changes to any file within a directory.
     $all_paths = array();
     foreach ($paths as $local) {
       foreach (DiffusionPathIDQuery::expandPathToRoot($local) as $path) {
         $all_paths[$path] = true;
       }
     }
     $all_paths = array_keys($all_paths);
 
     $path_ids =
       PhabricatorRepositoryCommitChangeParserWorker::lookupOrCreatePaths(
         $all_paths);
 
     $table = new DifferentialAffectedPath();
     $conn_w = $table->establishConnection('w');
 
     $sql = array();
     foreach ($path_ids as $path_id) {
       $sql[] = qsprintf(
         $conn_w,
         '(%d, %d, %d, %d)',
         $repository->getID(),
         $path_id,
         time(),
         $revision->getID());
     }
 
     queryfx(
       $conn_w,
       'DELETE FROM %T WHERE revisionID = %d',
       $table->getTableName(),
       $revision->getID());
     foreach (array_chunk($sql, 256) as $chunk) {
       queryfx(
         $conn_w,
         'INSERT INTO %T (repositoryID, pathID, epoch, revisionID) VALUES %Q',
         $table->getTableName(),
         implode(', ', $chunk));
     }
   }
 
   /**
    * Update the table connecting revisions to DVCS local hashes, so we can
    * identify revisions by commit/tree hashes.
    */
   private function updateRevisionHashTable(
     DifferentialRevision $revision,
     DifferentialDiff $diff) {
 
     $vcs = $diff->getSourceControlSystem();
     if ($vcs == DifferentialRevisionControlSystem::SVN) {
       // Subversion has no local commit or tree hash information, so we don't
       // have to do anything.
       return;
     }
 
     $property = id(new DifferentialDiffProperty())->loadOneWhere(
       'diffID = %d AND name = %s',
       $diff->getID(),
       'local:commits');
     if (!$property) {
       return;
     }
 
     $hashes = array();
 
     $data = $property->getData();
     switch ($vcs) {
       case DifferentialRevisionControlSystem::GIT:
         foreach ($data as $commit) {
           $hashes[] = array(
             ArcanistDifferentialRevisionHash::HASH_GIT_COMMIT,
             $commit['commit'],
           );
           $hashes[] = array(
             ArcanistDifferentialRevisionHash::HASH_GIT_TREE,
             $commit['tree'],
           );
         }
         break;
       case DifferentialRevisionControlSystem::MERCURIAL:
         foreach ($data as $commit) {
           $hashes[] = array(
             ArcanistDifferentialRevisionHash::HASH_MERCURIAL_COMMIT,
             $commit['rev'],
           );
         }
         break;
     }
 
     $conn_w = $revision->establishConnection('w');
 
     $sql = array();
     foreach ($hashes as $info) {
       list($type, $hash) = $info;
       $sql[] = qsprintf(
         $conn_w,
         '(%d, %s, %s)',
         $revision->getID(),
         $type,
         $hash);
     }
 
     queryfx(
       $conn_w,
       'DELETE FROM %T WHERE revisionID = %d',
       ArcanistDifferentialRevisionHash::TABLE_NAME,
       $revision->getID());
 
     if ($sql) {
       queryfx(
         $conn_w,
         'INSERT INTO %T (revisionID, type, hash) VALUES %Q',
         ArcanistDifferentialRevisionHash::TABLE_NAME,
         implode(', ', $sql));
     }
   }
 
   private function renderAffectedFilesForMail(DifferentialDiff $diff) {
     $changesets = $diff->getChangesets();
 
     $filenames = mpull($changesets, 'getDisplayFilename');
     sort($filenames);
 
     $count = count($filenames);
     $max = 250;
     if ($count > $max) {
       $filenames = array_slice($filenames, 0, $max);
       $filenames[] = pht('(%d more files...)', ($count - $max));
     }
 
     return implode("\n", $filenames);
   }
 
   private function renderPatchHTMLForMail($patch) {
     return phutil_tag('pre',
       array('style' => 'font-family: monospace;'), $patch);
   }
 
   private function buildPatchForMail(DifferentialDiff $diff) {
     $format = PhabricatorEnv::getEnvConfig('metamta.differential.patch-format');
 
     return id(new DifferentialRawDiffRenderer())
       ->setViewer($this->getActor())
       ->setFormat($format)
       ->setChangesets($diff->getChangesets())
       ->buildPatch();
   }
 
   protected function willPublish(PhabricatorLiskDAO $object, array $xactions) {
     // Reload to pick up the active diff and reviewer status.
     return id(new DifferentialRevisionQuery())
       ->setViewer($this->getActor())
       ->needReviewerStatus(true)
       ->needActiveDiffs(true)
       ->withIDs(array($object->getID()))
       ->executeOne();
   }
 
   protected function getCustomWorkerState() {
     return array(
       'changedPriorToCommitURI' => $this->changedPriorToCommitURI,
     );
   }
 
   protected function loadCustomWorkerState(array $state) {
     $this->changedPriorToCommitURI = idx($state, 'changedPriorToCommitURI');
     return $this;
   }
 
 }