Make updates of rejected revisions behave correctly again

Summary:
Ref T2222. Ref T4481. Specifically:

  - When a revision is updated, change all "Reject" reviewers to "Reject Prior".
  - Change status to "Needs Review".
  - Update the state logic to account for this properly.

Test Plan:
  - Created a revision as user A, with B as a reviewer.
  - Rejected as B.
  - Updated the revision as A.
  - Saw revision in "needs review" state, with B as a "Rejected Prior" reviewer.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4481, T2222

Differential Revision: https://secure.phabricator.com/D8402

src/applications/differential/constants/DifferentialReviewerStatus.php

@@ -7,6 +7,8 @@ final class DifferentialReviewerStatus {
   const STATUS_ACCEPTED = 'accepted';
   const STATUS_REJECTED = 'rejected';
   const STATUS_COMMENTED = 'commented';
+  const STATUS_ACCEPTED_OLDER = 'accepted-older';
+  const STATUS_REJECTED_OLDER = 'rejected-older';
 
   /**
    * Returns the relative strength of a status, used to pick a winner when a
@@ -27,8 +29,11 @@ final class DifferentialReviewerStatus {
 
       self::STATUS_BLOCKING   => 3,
 
-      self::STATUS_ACCEPTED   => 4,
+      self::STATUS_ACCEPTED_OLDER   => 4,
-      self::STATUS_REJECTED   => 4,
+      self::STATUS_REJECTED_OLDER   => 4,
+
+      self::STATUS_ACCEPTED   => 5,
+      self::STATUS_REJECTED   => 5,
     );
 
     return idx($map, $constant, 0);

src/applications/differential/editor/DifferentialTransactionEditor.php

@@ -137,6 +137,9 @@ final class DifferentialTransactionEditor
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
+    $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
+    $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
+
     switch ($xaction->getTransactionType()) {
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         $object->setViewPolicy($xaction->getNewValue());
@@ -151,12 +154,10 @@ final class DifferentialTransactionEditor
       case PhabricatorTransactions::TYPE_EDGE:
         return;
       case DifferentialTransaction::TYPE_UPDATE:
+        $object->setStatus($status_review);
         // TODO: Update the `diffPHID` once we add that.
         return;
       case DifferentialTransaction::TYPE_ACTION:
-        $status_review = ArcanistDifferentialRevisionStatus::NEEDS_REVIEW;
-        $status_revision = ArcanistDifferentialRevisionStatus::NEEDS_REVISION;
-
         switch ($xaction->getNewValue()) {
           case DifferentialAction::ACTION_RESIGN:
           case DifferentialAction::ACTION_ACCEPT:
@@ -203,6 +204,38 @@ final class DifferentialTransactionEditor
 
     $results = parent::expandTransaction($object, $xaction);
     switch ($xaction->getTransactionType()) {
+      case DifferentialTransaction::TYPE_UPDATE:
+        $new_accept = DifferentialReviewerStatus::STATUS_ACCEPTED;
+        $new_reject = DifferentialReviewerStatus::STATUS_REJECTED;
+        $old_accept = DifferentialReviewerStatus::STATUS_ACCEPTED_OLDER;
+        $old_reject = DifferentialReviewerStatus::STATUS_REJECTED_OLDER;
+
+        // 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".
+        $edits = array();
+        foreach ($object->getReviewerStatus() as $reviewer) {
+          if ($reviewer->getStatus() == $new_reject) {
+            $edits[$reviewer->getReviewerPHID()] = array(
+              'data' => array(
+                'status' => $old_reject,
+              ),
+            );
+          }
+
+          // TODO: If sticky accept is off, do a similar update for accepts.
+        }
+
+        if ($edits) {
+          $results[] = id(new DifferentialTransaction())
+            ->setTransactionType($type_edge)
+            ->setMetadataValue('edge:type', $edge_reviewer)
+            ->setIgnoreOnNoEffect(true)
+            ->setNewValue(array('+' => $edits));
+        }
+        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
@@ -433,10 +466,12 @@ final class DifferentialTransactionEditor
         //
         //   - 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;
         $has_blocking_reviewer = false;
         foreach ($new_revision->getReviewerStatus() as $reviewer) {
           $reviewer_status = $reviewer->getStatus();
@@ -444,6 +479,9 @@ final class DifferentialTransactionEditor
             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;
@@ -458,6 +496,7 @@ final class DifferentialTransactionEditor
         $new_status = null;
         if ($has_accepting_user &&
             !$has_rejecting_reviewer &&
+            !$has_rejecting_older_reviewer &&
             !$has_blocking_reviewer) {
           $new_status = $status_accepted;
         } else if ($has_rejecting_reviewer) {

src/applications/differential/view/DifferentialReviewersView.php

@@ -58,6 +58,12 @@ final class DifferentialReviewersView extends AphrontView {
           }
           break;
 
+        case DifferentialReviewerStatus::STATUS_ACCEPTED_OLDER:
+          $item->setIcon(
+            'accept-dark',
+            pht('Accepted Prior Diff'));
+          break;
+
         case DifferentialReviewerStatus::STATUS_REJECTED:
           if ($is_current) {
             $item->setIcon(
@@ -70,6 +76,12 @@ final class DifferentialReviewersView extends AphrontView {
           }
           break;
 
+        case DifferentialReviewerStatus::STATUS_REJECTED_OLDER:
+          $item->setIcon(
+            'reject-dark',
+            pht('Rejected Prior Diff'));
+          break;
+
         case DifferentialReviewerStatus::STATUS_COMMENTED:
           if ($is_current) {
             $item->setIcon(