Separate revision updates into two separate comments

Summary:
Ref T2222. Instead of writing one comment which performs both a diff update and adds a comment, write two comments, one for each action. These will translate directly into ApplicationTransactions writes.

This has a small impact on the UX: these updates now render in two rows, instead of one. After T2222, they'll automerge back together.

{F111909}

Test Plan: Updated a revision.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2222

Differential Revision: https://secure.phabricator.com/D8200

src/applications/differential/editor/DifferentialRevisionEditor.php

@@ -786,21 +786,29 @@ final class DifferentialRevisionEditor extends PhabricatorEditor {
 
 
   private function createComment() {
-    $comment = id(new DifferentialComment())
+    $template = id(new DifferentialComment())
       ->setAuthorPHID($this->getActorPHID())
-      ->setRevision($this->revision)
+      ->setRevision($this->revision);
-      ->setContent($this->getComments())
+    if ($this->contentSource) {
+      $template->setContentSource($this->contentSource);
+    }
+
+    // Write the "update active diff" transaction.
+    id(clone $template)
       ->setAction(DifferentialAction::ACTION_UPDATE)
       ->setMetadata(
         array(
           DifferentialComment::METADATA_DIFF_ID => $this->getDiff()->getID(),
-        ));
+        ))
+      ->save();
 
-    if ($this->contentSource) {
+    // If we have a comment, write the "add a comment" transaction.
-      $comment->setContentSource($this->contentSource);
+    if (strlen($this->getComments())) {
+      id(clone $template)
+        ->setAction(DifferentialAction::ACTION_COMMENT)
+        ->setContent($this->getComments())
+        ->save();
     }
-
-    $comment->save();
   }
 
   private function updateAuxiliaryFields() {

src/applications/differential/storage/DifferentialComment.php

@@ -127,24 +127,27 @@ final class DifferentialComment extends DifferentialDAO
     $this->openTransaction();
       $result = parent::save();
 
-      $content_source = PhabricatorContentSource::newForSource(
+      if (strlen($this->getContent())) {
-        PhabricatorContentSource::SOURCE_LEGACY,
+        $content_source = PhabricatorContentSource::newForSource(
-        array());
+          PhabricatorContentSource::SOURCE_LEGACY,
+          array());
 
-      $xaction_phid = PhabricatorPHID::generateNewPHID(
+        $xaction_phid = PhabricatorPHID::generateNewPHID(
-        PhabricatorApplicationTransactionPHIDTypeTransaction::TYPECONST,
+          PhabricatorApplicationTransactionPHIDTypeTransaction::TYPECONST,
-        DifferentialPHIDTypeRevision::TYPECONST);
+          DifferentialPHIDTypeRevision::TYPECONST);
+
+        $proxy = $this->getProxyComment();
+        $proxy
+          ->setAuthorPHID($this->getAuthorPHID())
+          ->setViewPolicy('public')
+          ->setEditPolicy($this->getAuthorPHID())
+          ->setContentSource($content_source)
+          ->setCommentVersion(1)
+          ->setLegacyCommentID($this->getID())
+          ->setTransactionPHID($xaction_phid)
+          ->save();
+      }
 
-      $proxy = $this->getProxyComment();
-      $proxy
-        ->setAuthorPHID($this->getAuthorPHID())
-        ->setViewPolicy('public')
-        ->setEditPolicy($this->getAuthorPHID())
-        ->setContentSource($content_source)
-        ->setCommentVersion(1)
-        ->setLegacyCommentID($this->getID())
-        ->setTransactionPHID($xaction_phid)
-        ->save();
     $this->saveTransaction();
 
     return $result;