diff --git a/externals/javelin b/externals/javelin
index a2672d3292..32c6e43f4b 160000
--- a/externals/javelin
+++ b/externals/javelin
@@ -1 +1 @@
-Subproject commit a2672d329212c90bda4f7979400a5149f9e967d2
+Subproject commit 32c6e43f4b8b84df940bed8ed8d073e67f6c2b28
diff --git a/src/__celerity_resource_map__.php b/src/__celerity_resource_map__.php
index ce9285077a..1d3933a04f 100644
--- a/src/__celerity_resource_map__.php
+++ b/src/__celerity_resource_map__.php
@@ -709,7 +709,7 @@ celerity_register_resource_map(array(
   ),
   'aphront-tooltip-css' =>
   array(
-    'uri' => '/res/32665c0e/rsrc/css/aphront/tooltip.css',
+    'uri' => '/res/79c36254/rsrc/css/aphront/tooltip.css',
     'type' => 'css',
     'requires' =>
     array(
@@ -1199,7 +1199,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-differential-populate' =>
   array(
-    'uri' => '/res/781dd9a5/rsrc/js/application/differential/behavior-populate.js',
+    'uri' => '/res/769b91da/rsrc/js/application/differential/behavior-populate.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1678,7 +1678,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-phabricator-transaction-comment-form' =>
   array(
-    'uri' => '/res/bdc362ee/rsrc/js/application/transactions/behavior-transaction-comment-form.js',
+    'uri' => '/res/acc3ada1/rsrc/js/application/transactions/behavior-transaction-comment-form.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1691,7 +1691,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-phabricator-transaction-list' =>
   array(
-    'uri' => '/res/212f97ba/rsrc/js/application/transactions/behavior-transaction-list.js',
+    'uri' => '/res/307a71af/rsrc/js/application/transactions/behavior-transaction-list.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1881,7 +1881,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-dom' =>
   array(
-    'uri' => '/res/4c79cf8a/rsrc/js/javelin/lib/DOM.js',
+    'uri' => '/res/2826c532/rsrc/js/javelin/lib/DOM.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -2063,7 +2063,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-stratcom' =>
   array(
-    'uri' => '/res/3ec22c29/rsrc/js/javelin/core/Stratcom.js',
+    'uri' => '/res/c81f64eb/rsrc/js/javelin/core/Stratcom.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -2869,7 +2869,7 @@ celerity_register_resource_map(array(
   ),
   'phabricator-tooltip' =>
   array(
-    'uri' => '/res/bcddf5de/rsrc/js/application/core/ToolTip.js',
+    'uri' => '/res/55d76b9b/rsrc/js/application/core/ToolTip.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -3214,7 +3214,7 @@ celerity_register_resource_map(array(
 ), array(
   'packages' =>
   array(
-    '6d338e1d' =>
+    '43f32e36' =>
     array(
       'name' => 'core.pkg.css',
       'symbols' =>
@@ -3259,10 +3259,10 @@ celerity_register_resource_map(array(
         37 => 'phabricator-object-item-list-view-css',
         38 => 'global-drag-and-drop-css',
       ),
-      'uri' => '/res/pkg/6d338e1d/core.pkg.css',
+      'uri' => '/res/pkg/43f32e36/core.pkg.css',
       'type' => 'css',
     ),
-    '70c8162b' =>
+    '2921e259' =>
     array(
       'name' => 'core.pkg.js',
       'symbols' =>
@@ -3300,7 +3300,7 @@ celerity_register_resource_map(array(
         30 => 'phabricator-file-upload',
         31 => 'javelin-behavior-global-drag-and-drop',
       ),
-      'uri' => '/res/pkg/70c8162b/core.pkg.js',
+      'uri' => '/res/pkg/2921e259/core.pkg.js',
       'type' => 'js',
     ),
     '8edbada5' =>
@@ -3338,7 +3338,7 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/380df740/differential.pkg.css',
       'type' => 'css',
     ),
-    '8b98837e' =>
+    '76556a8f' =>
     array(
       'name' => 'differential.pkg.js',
       'symbols' =>
@@ -3363,7 +3363,7 @@ celerity_register_resource_map(array(
         17 => 'javelin-behavior-differential-toggle-files',
         18 => 'javelin-behavior-differential-user-select',
       ),
-      'uri' => '/res/pkg/8b98837e/differential.pkg.js',
+      'uri' => '/res/pkg/76556a8f/differential.pkg.js',
       'type' => 'js',
     ),
     'c8ce2d88' =>
@@ -3389,7 +3389,7 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/5e68be89/diffusion.pkg.js',
       'type' => 'js',
     ),
-    'db6d724d' =>
+    'fbeded59' =>
     array(
       'name' => 'javelin.pkg.js',
       'symbols' =>
@@ -3414,7 +3414,7 @@ celerity_register_resource_map(array(
         17 => 'javelin-typeahead-ondemand-source',
         18 => 'javelin-tokenizer',
       ),
-      'uri' => '/res/pkg/db6d724d/javelin.pkg.js',
+      'uri' => '/res/pkg/fbeded59/javelin.pkg.js',
       'type' => 'js',
     ),
     '7839ae2d' =>
@@ -3448,23 +3448,23 @@ celerity_register_resource_map(array(
   'reverse' =>
   array(
     'aphront-attached-file-view-css' => '7839ae2d',
-    'aphront-crumbs-view-css' => '6d338e1d',
-    'aphront-dialog-view-css' => '6d338e1d',
-    'aphront-error-view-css' => '6d338e1d',
-    'aphront-form-view-css' => '6d338e1d',
+    'aphront-crumbs-view-css' => '43f32e36',
+    'aphront-dialog-view-css' => '43f32e36',
+    'aphront-error-view-css' => '43f32e36',
+    'aphront-form-view-css' => '43f32e36',
     'aphront-headsup-action-list-view-css' => '380df740',
-    'aphront-headsup-view-css' => '6d338e1d',
-    'aphront-list-filter-view-css' => '6d338e1d',
-    'aphront-pager-view-css' => '6d338e1d',
-    'aphront-panel-view-css' => '6d338e1d',
-    'aphront-side-nav-view-css' => '6d338e1d',
-    'aphront-table-view-css' => '6d338e1d',
-    'aphront-tokenizer-control-css' => '6d338e1d',
-    'aphront-tooltip-css' => '6d338e1d',
-    'aphront-typeahead-control-css' => '6d338e1d',
+    'aphront-headsup-view-css' => '43f32e36',
+    'aphront-list-filter-view-css' => '43f32e36',
+    'aphront-pager-view-css' => '43f32e36',
+    'aphront-panel-view-css' => '43f32e36',
+    'aphront-side-nav-view-css' => '43f32e36',
+    'aphront-table-view-css' => '43f32e36',
+    'aphront-tokenizer-control-css' => '43f32e36',
+    'aphront-tooltip-css' => '43f32e36',
+    'aphront-typeahead-control-css' => '43f32e36',
     'differential-changeset-view-css' => '380df740',
     'differential-core-view-css' => '380df740',
-    'differential-inline-comment-editor' => '8b98837e',
+    'differential-inline-comment-editor' => '76556a8f',
     'differential-local-commits-view-css' => '380df740',
     'differential-results-table-css' => '380df740',
     'differential-revision-add-comment-css' => '380df740',
@@ -3475,117 +3475,117 @@ celerity_register_resource_map(array(
     'differential-table-of-contents-css' => '380df740',
     'diffusion-commit-view-css' => 'c8ce2d88',
     'diffusion-icons-css' => 'c8ce2d88',
-    'global-drag-and-drop-css' => '6d338e1d',
+    'global-drag-and-drop-css' => '43f32e36',
     'inline-comment-summary-css' => '380df740',
-    'javelin-aphlict' => '70c8162b',
-    'javelin-behavior' => 'db6d724d',
-    'javelin-behavior-aphlict-dropdown' => '70c8162b',
-    'javelin-behavior-aphlict-listen' => '70c8162b',
-    'javelin-behavior-aphront-basic-tokenizer' => '70c8162b',
-    'javelin-behavior-aphront-drag-and-drop' => '8b98837e',
-    'javelin-behavior-aphront-drag-and-drop-textarea' => '8b98837e',
-    'javelin-behavior-aphront-form-disable-on-submit' => '70c8162b',
+    'javelin-aphlict' => '2921e259',
+    'javelin-behavior' => 'fbeded59',
+    'javelin-behavior-aphlict-dropdown' => '2921e259',
+    'javelin-behavior-aphlict-listen' => '2921e259',
+    'javelin-behavior-aphront-basic-tokenizer' => '2921e259',
+    'javelin-behavior-aphront-drag-and-drop' => '76556a8f',
+    'javelin-behavior-aphront-drag-and-drop-textarea' => '76556a8f',
+    'javelin-behavior-aphront-form-disable-on-submit' => '2921e259',
     'javelin-behavior-audit-preview' => '5e68be89',
     'javelin-behavior-dark-console' => '8edbada5',
     'javelin-behavior-dark-console-ajax' => '8edbada5',
-    'javelin-behavior-device' => '70c8162b',
-    'javelin-behavior-differential-accept-with-errors' => '8b98837e',
-    'javelin-behavior-differential-add-reviewers-and-ccs' => '8b98837e',
-    'javelin-behavior-differential-comment-jump' => '8b98837e',
-    'javelin-behavior-differential-diff-radios' => '8b98837e',
-    'javelin-behavior-differential-dropdown-menus' => '8b98837e',
-    'javelin-behavior-differential-edit-inline-comments' => '8b98837e',
-    'javelin-behavior-differential-feedback-preview' => '8b98837e',
-    'javelin-behavior-differential-keyboard-navigation' => '8b98837e',
-    'javelin-behavior-differential-populate' => '8b98837e',
-    'javelin-behavior-differential-show-more' => '8b98837e',
-    'javelin-behavior-differential-toggle-files' => '8b98837e',
-    'javelin-behavior-differential-user-select' => '8b98837e',
+    'javelin-behavior-device' => '2921e259',
+    'javelin-behavior-differential-accept-with-errors' => '76556a8f',
+    'javelin-behavior-differential-add-reviewers-and-ccs' => '76556a8f',
+    'javelin-behavior-differential-comment-jump' => '76556a8f',
+    'javelin-behavior-differential-diff-radios' => '76556a8f',
+    'javelin-behavior-differential-dropdown-menus' => '76556a8f',
+    'javelin-behavior-differential-edit-inline-comments' => '76556a8f',
+    'javelin-behavior-differential-feedback-preview' => '76556a8f',
+    'javelin-behavior-differential-keyboard-navigation' => '76556a8f',
+    'javelin-behavior-differential-populate' => '76556a8f',
+    'javelin-behavior-differential-show-more' => '76556a8f',
+    'javelin-behavior-differential-toggle-files' => '76556a8f',
+    'javelin-behavior-differential-user-select' => '76556a8f',
     'javelin-behavior-diffusion-commit-graph' => '5e68be89',
     'javelin-behavior-diffusion-pull-lastmodified' => '5e68be89',
     'javelin-behavior-error-log' => '8edbada5',
-    'javelin-behavior-global-drag-and-drop' => '70c8162b',
-    'javelin-behavior-konami' => '70c8162b',
-    'javelin-behavior-lightbox-attachments' => '70c8162b',
+    'javelin-behavior-global-drag-and-drop' => '2921e259',
+    'javelin-behavior-konami' => '2921e259',
+    'javelin-behavior-lightbox-attachments' => '2921e259',
     'javelin-behavior-maniphest-batch-selector' => '7707de41',
     'javelin-behavior-maniphest-subpriority-editor' => '7707de41',
     'javelin-behavior-maniphest-transaction-controls' => '7707de41',
     'javelin-behavior-maniphest-transaction-expand' => '7707de41',
     'javelin-behavior-maniphest-transaction-preview' => '7707de41',
-    'javelin-behavior-phabricator-active-nav' => '70c8162b',
-    'javelin-behavior-phabricator-autofocus' => '70c8162b',
-    'javelin-behavior-phabricator-keyboard-shortcuts' => '70c8162b',
-    'javelin-behavior-phabricator-nav' => '70c8162b',
-    'javelin-behavior-phabricator-object-selector' => '8b98837e',
-    'javelin-behavior-phabricator-oncopy' => '70c8162b',
-    'javelin-behavior-phabricator-remarkup-assist' => '70c8162b',
-    'javelin-behavior-phabricator-search-typeahead' => '70c8162b',
-    'javelin-behavior-phabricator-tooltips' => '70c8162b',
-    'javelin-behavior-phabricator-watch-anchor' => '70c8162b',
-    'javelin-behavior-refresh-csrf' => '70c8162b',
-    'javelin-behavior-repository-crossreference' => '8b98837e',
-    'javelin-behavior-toggle-class' => '70c8162b',
-    'javelin-behavior-workflow' => '70c8162b',
-    'javelin-dom' => 'db6d724d',
-    'javelin-event' => 'db6d724d',
-    'javelin-install' => 'db6d724d',
-    'javelin-json' => 'db6d724d',
-    'javelin-mask' => 'db6d724d',
-    'javelin-request' => 'db6d724d',
-    'javelin-resource' => 'db6d724d',
-    'javelin-stratcom' => 'db6d724d',
-    'javelin-tokenizer' => 'db6d724d',
-    'javelin-typeahead' => 'db6d724d',
-    'javelin-typeahead-normalizer' => 'db6d724d',
-    'javelin-typeahead-ondemand-source' => 'db6d724d',
-    'javelin-typeahead-preloaded-source' => 'db6d724d',
-    'javelin-typeahead-source' => 'db6d724d',
-    'javelin-uri' => 'db6d724d',
-    'javelin-util' => 'db6d724d',
-    'javelin-vector' => 'db6d724d',
-    'javelin-workflow' => 'db6d724d',
-    'lightbox-attachment-css' => '6d338e1d',
+    'javelin-behavior-phabricator-active-nav' => '2921e259',
+    'javelin-behavior-phabricator-autofocus' => '2921e259',
+    'javelin-behavior-phabricator-keyboard-shortcuts' => '2921e259',
+    'javelin-behavior-phabricator-nav' => '2921e259',
+    'javelin-behavior-phabricator-object-selector' => '76556a8f',
+    'javelin-behavior-phabricator-oncopy' => '2921e259',
+    'javelin-behavior-phabricator-remarkup-assist' => '2921e259',
+    'javelin-behavior-phabricator-search-typeahead' => '2921e259',
+    'javelin-behavior-phabricator-tooltips' => '2921e259',
+    'javelin-behavior-phabricator-watch-anchor' => '2921e259',
+    'javelin-behavior-refresh-csrf' => '2921e259',
+    'javelin-behavior-repository-crossreference' => '76556a8f',
+    'javelin-behavior-toggle-class' => '2921e259',
+    'javelin-behavior-workflow' => '2921e259',
+    'javelin-dom' => 'fbeded59',
+    'javelin-event' => 'fbeded59',
+    'javelin-install' => 'fbeded59',
+    'javelin-json' => 'fbeded59',
+    'javelin-mask' => 'fbeded59',
+    'javelin-request' => 'fbeded59',
+    'javelin-resource' => 'fbeded59',
+    'javelin-stratcom' => 'fbeded59',
+    'javelin-tokenizer' => 'fbeded59',
+    'javelin-typeahead' => 'fbeded59',
+    'javelin-typeahead-normalizer' => 'fbeded59',
+    'javelin-typeahead-ondemand-source' => 'fbeded59',
+    'javelin-typeahead-preloaded-source' => 'fbeded59',
+    'javelin-typeahead-source' => 'fbeded59',
+    'javelin-uri' => 'fbeded59',
+    'javelin-util' => 'fbeded59',
+    'javelin-vector' => 'fbeded59',
+    'javelin-workflow' => 'fbeded59',
+    'lightbox-attachment-css' => '43f32e36',
     'maniphest-task-summary-css' => '7839ae2d',
     'maniphest-transaction-detail-css' => '7839ae2d',
-    'phabricator-app-buttons-css' => '6d338e1d',
-    'phabricator-busy' => '70c8162b',
+    'phabricator-app-buttons-css' => '43f32e36',
+    'phabricator-busy' => '2921e259',
     'phabricator-content-source-view-css' => '380df740',
-    'phabricator-core-buttons-css' => '6d338e1d',
-    'phabricator-core-css' => '6d338e1d',
-    'phabricator-crumbs-view-css' => '6d338e1d',
-    'phabricator-directory-css' => '6d338e1d',
-    'phabricator-drag-and-drop-file-upload' => '8b98837e',
-    'phabricator-dropdown-menu' => '70c8162b',
-    'phabricator-file-upload' => '70c8162b',
-    'phabricator-filetree-view-css' => '6d338e1d',
-    'phabricator-flag-css' => '6d338e1d',
-    'phabricator-form-view-css' => '6d338e1d',
-    'phabricator-header-view-css' => '6d338e1d',
-    'phabricator-jump-nav' => '6d338e1d',
-    'phabricator-keyboard-shortcut' => '70c8162b',
-    'phabricator-keyboard-shortcut-manager' => '70c8162b',
-    'phabricator-main-menu-view' => '6d338e1d',
-    'phabricator-menu-item' => '70c8162b',
-    'phabricator-nav-view-css' => '6d338e1d',
-    'phabricator-notification' => '70c8162b',
-    'phabricator-notification-css' => '6d338e1d',
-    'phabricator-notification-menu-css' => '6d338e1d',
-    'phabricator-object-item-list-view-css' => '6d338e1d',
+    'phabricator-core-buttons-css' => '43f32e36',
+    'phabricator-core-css' => '43f32e36',
+    'phabricator-crumbs-view-css' => '43f32e36',
+    'phabricator-directory-css' => '43f32e36',
+    'phabricator-drag-and-drop-file-upload' => '76556a8f',
+    'phabricator-dropdown-menu' => '2921e259',
+    'phabricator-file-upload' => '2921e259',
+    'phabricator-filetree-view-css' => '43f32e36',
+    'phabricator-flag-css' => '43f32e36',
+    'phabricator-form-view-css' => '43f32e36',
+    'phabricator-header-view-css' => '43f32e36',
+    'phabricator-jump-nav' => '43f32e36',
+    'phabricator-keyboard-shortcut' => '2921e259',
+    'phabricator-keyboard-shortcut-manager' => '2921e259',
+    'phabricator-main-menu-view' => '43f32e36',
+    'phabricator-menu-item' => '2921e259',
+    'phabricator-nav-view-css' => '43f32e36',
+    'phabricator-notification' => '2921e259',
+    'phabricator-notification-css' => '43f32e36',
+    'phabricator-notification-menu-css' => '43f32e36',
+    'phabricator-object-item-list-view-css' => '43f32e36',
     'phabricator-object-selector-css' => '380df740',
-    'phabricator-paste-file-upload' => '70c8162b',
-    'phabricator-prefab' => '70c8162b',
+    'phabricator-paste-file-upload' => '2921e259',
+    'phabricator-prefab' => '2921e259',
     'phabricator-project-tag-css' => '7839ae2d',
-    'phabricator-remarkup-css' => '6d338e1d',
-    'phabricator-shaped-request' => '8b98837e',
-    'phabricator-side-menu-view-css' => '6d338e1d',
-    'phabricator-standard-page-view' => '6d338e1d',
-    'phabricator-textareautils' => '70c8162b',
-    'phabricator-tooltip' => '70c8162b',
-    'phabricator-transaction-view-css' => '6d338e1d',
-    'sprite-apps-large-css' => '6d338e1d',
-    'sprite-gradient-css' => '6d338e1d',
-    'sprite-icon-css' => '6d338e1d',
-    'sprite-menu-css' => '6d338e1d',
-    'syntax-highlighting-css' => '6d338e1d',
+    'phabricator-remarkup-css' => '43f32e36',
+    'phabricator-shaped-request' => '76556a8f',
+    'phabricator-side-menu-view-css' => '43f32e36',
+    'phabricator-standard-page-view' => '43f32e36',
+    'phabricator-textareautils' => '2921e259',
+    'phabricator-tooltip' => '2921e259',
+    'phabricator-transaction-view-css' => '43f32e36',
+    'sprite-apps-large-css' => '43f32e36',
+    'sprite-gradient-css' => '43f32e36',
+    'sprite-icon-css' => '43f32e36',
+    'sprite-menu-css' => '43f32e36',
+    'syntax-highlighting-css' => '43f32e36',
   ),
 ));
diff --git a/src/aphront/AphrontRequest.php b/src/aphront/AphrontRequest.php
index 762d2394cd..b98011305f 100644
--- a/src/aphront/AphrontRequest.php
+++ b/src/aphront/AphrontRequest.php
@@ -353,7 +353,16 @@ final class AphrontRequest {
    * @return  dict<string, string>  Original request parameters.
    */
   public function getPassthroughRequestParameters() {
-    $data = self::flattenData($this->getRequestData());
+    return self::flattenData($this->getPassthruRequestData());
+  }
+
+  /**
+   * Get request data other than "magic" parameters.
+   *
+   * @return dict<string, wild> Request data, with magic filtered out.
+   */
+  public function getPassthroughRequestData() {
+    $data = $this->getRequestData();
 
     // Remove magic parameters like __dialog__ and __ajax__.
     foreach ($data as $key => $value) {
diff --git a/src/applications/draft/storage/PhabricatorDraft.php b/src/applications/draft/storage/PhabricatorDraft.php
index ed952c0d48..21daa14b12 100644
--- a/src/applications/draft/storage/PhabricatorDraft.php
+++ b/src/applications/draft/storage/PhabricatorDraft.php
@@ -28,4 +28,53 @@ final class PhabricatorDraft extends PhabricatorDraftDAO {
     return parent::replace();
   }
 
+  public static function newFromUserAndKey(PhabricatorUser $user, $key) {
+    if ($user->getPHID() && strlen($key)) {
+      $draft = id(new PhabricatorDraft())->loadOneWhere(
+        'authorPHID = %s AND draftKey = %s',
+        $user->getPHID(),
+        $key);
+      if ($draft) {
+        return $draft;
+      }
+    }
+
+    $draft = new PhabricatorDraft();
+    if ($user->getPHID()) {
+      $draft
+        ->setAuthorPHID($user->getPHID())
+        ->setDraftKey($key);
+    }
+
+    return $draft;
+  }
+
+  public static function buildFromRequest(AphrontRequest $request) {
+    $user = $request->getUser();
+    if (!$user->getPHID()) {
+      return null;
+    }
+
+    if (!$request->getStr('__draft__')) {
+      return null;
+    }
+
+    $draft = id(new PhabricatorDraft())
+      ->setAuthorPHID($user->getPHID())
+      ->setDraftKey($request->getStr('__draft__'));
+
+    // If this is a preview, add other data. If not, leave the draft empty so
+    // that replaceOrDelete() will delete it.
+    if ($request->isPreviewRequest()) {
+      $other_data = $request->getPassthroughRequestData();
+      unset($other_data['comment']);
+
+      $draft
+        ->setDraft($request->getStr('comment'))
+        ->setMetadata($other_data);
+    }
+
+    return $draft;
+  }
+
 }
diff --git a/src/applications/macro/controller/PhabricatorMacroCommentController.php b/src/applications/macro/controller/PhabricatorMacroCommentController.php
index a1ba47212a..81844dc529 100644
--- a/src/applications/macro/controller/PhabricatorMacroCommentController.php
+++ b/src/applications/macro/controller/PhabricatorMacroCommentController.php
@@ -23,6 +23,7 @@ final class PhabricatorMacroCommentController
     }
 
     $is_preview = $request->isPreviewRequest();
+    $draft = PhabricatorDraft::buildFromRequest($request);
 
     $view_uri = $this->getApplicationURI('/view/'.$macro->getID().'/');
 
@@ -52,6 +53,10 @@ final class PhabricatorMacroCommentController
         ->setException($ex);
     }
 
+    if ($draft) {
+      $draft->replaceOrDelete();
+    }
+
     if ($request->isAjax()) {
       return id(new PhabricatorApplicationTransactionResponse())
         ->setViewer($user)
diff --git a/src/applications/macro/controller/PhabricatorMacroViewController.php b/src/applications/macro/controller/PhabricatorMacroViewController.php
index 547ba80c30..b7fb10d963 100644
--- a/src/applications/macro/controller/PhabricatorMacroViewController.php
+++ b/src/applications/macro/controller/PhabricatorMacroViewController.php
@@ -83,8 +83,11 @@ final class PhabricatorMacroViewController
       ? pht('Add Comment')
       : pht('Lavish Praise');
 
+    $draft = PhabricatorDraft::newFromUserAndKey($user, $macro->getPHID());
+
     $add_comment_form = id(new PhabricatorApplicationTransactionCommentView())
       ->setUser($user)
+      ->setDraft($draft)
       ->setAction($this->getApplicationURI('/comment/'.$macro->getID().'/'))
       ->setSubmitButtonName($submit_button_name);
 
diff --git a/src/applications/pholio/controller/PholioMockCommentController.php b/src/applications/pholio/controller/PholioMockCommentController.php
index 8ee3c8d218..51ade41e94 100644
--- a/src/applications/pholio/controller/PholioMockCommentController.php
+++ b/src/applications/pholio/controller/PholioMockCommentController.php
@@ -30,6 +30,8 @@ final class PholioMockCommentController extends PholioController {
 
     $is_preview = $request->isPreviewRequest();
 
+    $draft = PhabricatorDraft::buildFromRequest($request);
+
     $mock_uri = '/M'.$mock->getID();
 
     $comment = $request->getStr('comment');
@@ -61,6 +63,10 @@ final class PholioMockCommentController extends PholioController {
         ->setException($ex);
     }
 
+    if ($draft) {
+      $draft->replaceOrDelete();
+    }
+
     if ($request->isAjax()) {
       return id(new PhabricatorApplicationTransactionResponse())
         ->setViewer($user)
diff --git a/src/applications/pholio/controller/PholioMockViewController.php b/src/applications/pholio/controller/PholioMockViewController.php
index 9f23d46e1f..826402524c 100644
--- a/src/applications/pholio/controller/PholioMockViewController.php
+++ b/src/applications/pholio/controller/PholioMockViewController.php
@@ -159,6 +159,8 @@ final class PholioMockViewController extends PholioController {
   private function buildAddCommentView(PholioMock $mock) {
     $user = $this->getRequest()->getUser();
 
+    $draft = PhabricatorDraft::newFromUserAndKey($user, $mock->getPHID());
+
     $is_serious = PhabricatorEnv::getEnvConfig('phabricator.serious-business');
 
     $title = $is_serious
@@ -174,6 +176,7 @@ final class PholioMockViewController extends PholioController {
 
     $form = id(new PhabricatorApplicationTransactionCommentView())
       ->setUser($user)
+      ->setDraft($draft)
       ->setSubmitButtonName($button_name)
       ->setAction($this->getApplicationURI('/comment/'.$mock->getID().'/'));
 
diff --git a/src/applications/transactions/view/PhabricatorApplicationTransactionCommentView.php b/src/applications/transactions/view/PhabricatorApplicationTransactionCommentView.php
index 26e20c853c..86f947d43e 100644
--- a/src/applications/transactions/view/PhabricatorApplicationTransactionCommentView.php
+++ b/src/applications/transactions/view/PhabricatorApplicationTransactionCommentView.php
@@ -13,6 +13,17 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
   private $previewToggleID;
   private $formID;
   private $statusID;
+  private $commentID;
+  private $draft;
+
+  public function setDraft(PhabricatorDraft $draft) {
+    $this->draft = $draft;
+    return $this;
+  }
+
+  public function getDraft() {
+    return $this->draft;
+  }
 
   public function setSubmitButtonName($submit_button_name) {
     $this->submitButtonName = $submit_button_name;
@@ -47,12 +58,14 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
         'timelineID'    => $this->getPreviewTimelineID(),
         'panelID'       => $this->getPreviewPanelID(),
         'statusID'      => $this->getStatusID(),
+        'commentID'     => $this->getCommentID(),
 
         'loadingString' => pht('Loading Preview...'),
         'savingString'  => pht('Saving Draft...'),
         'draftString'   => pht('Saved Draft'),
 
         'actionURI'     => $this->getAction(),
+        'draftKey'      => $this->getDraft()->getDraftKey(),
       ));
 
     return self::renderSingleView(
@@ -70,6 +83,11 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
       ),
       '');
 
+    $draft_comment = '';
+    if ($this->getDraft()) {
+      $draft_comment = $this->getDraft()->getDraft();
+    }
+
     return id(new AphrontFormView())
       ->setUser($this->getUser())
       ->setFlexible(true)
@@ -79,9 +97,11 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
       ->setID($this->getFormID())
       ->appendChild(
         id(new PhabricatorRemarkupControl())
+          ->setID($this->getCommentID())
           ->setName('comment')
           ->setLabel(pht('Comment'))
           ->setUser($this->getUser()))
+          ->setValue($draft_comment)
       ->appendChild(
         id(new AphrontFormSubmitControl())
           ->setValue($this->getSubmitButtonName()))
@@ -143,5 +163,12 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
     return $this->statusID;
   }
 
+  private function getCommentID() {
+    if (!$this->commentID) {
+      $this->commentID = celerity_generate_unique_node_id();
+    }
+    return $this->commentID;
+  }
+
 }
 
diff --git a/webroot/rsrc/js/application/transactions/behavior-transaction-comment-form.js b/webroot/rsrc/js/application/transactions/behavior-transaction-comment-form.js
index 5459584557..2c740b8889 100644
--- a/webroot/rsrc/js/application/transactions/behavior-transaction-comment-form.js
+++ b/webroot/rsrc/js/application/transactions/behavior-transaction-comment-form.js
@@ -10,9 +10,19 @@ JX.behavior('phabricator-transaction-comment-form', function(config) {
 
   var form = JX.$(config.formID);
 
+  JX.DOM.listen(form, 'willClear', null, function(e) {
+    e.kill();
+    JX.$(config.commentID).value = '';
+  });
+
   var getdata = function() {
     var obj = JX.DOM.convertFormToDictionary(form);
     obj.__preview__ = 1;
+
+    if (config.draftKey) {
+      obj.__draft__ = config.draftKey;
+    }
+
     return obj;
   };
 
diff --git a/webroot/rsrc/js/application/transactions/behavior-transaction-list.js b/webroot/rsrc/js/application/transactions/behavior-transaction-list.js
index 481b39b8b5..0658ac2ebf 100644
--- a/webroot/rsrc/js/application/transactions/behavior-transaction-list.js
+++ b/webroot/rsrc/js/application/transactions/behavior-transaction-list.js
@@ -81,7 +81,11 @@ JX.behavior('phabricator-transaction-list', function(config) {
     JX.Workflow.newFromForm(form, {anchor: next_anchor})
       .setHandler(function(response) {
         ontransactions(response);
-        form.reset();
+
+        var e = JX.DOM.invoke(form, 'willClear');
+        if (!e.getPrevented()) {
+          form.reset();
+        }
       })
       .start();