Make some Differential comment actions (like "Accept" and "Reject") conflict with one another

Summary:
Ref T11114. When a user selects "Accept", and then selects "Reject", remove the "Accept". It does not make sense to both accept and reject a revision.

For now, every one of the "actions" conflicts: accept, reject, resign, claim, close, commandeer, etc, etc. I couldn't come up with any combinations that it seems like users are reasonably likely to want to try, and we haven't received combo-action requests in the past that I can recall.

Test Plan:
  - Selected "Accept", then selected "Reject". One replaced the other.
  - Selected "Accept", then selected "Change Subscribers". Both co-existed happily.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11114

Differential Revision: https://secure.phabricator.com/D17132

src/applications/differential/xaction/DifferentialRevisionActionTransaction.php

@@ -73,6 +73,18 @@ abstract class DifferentialRevisionActionTransaction
 
         $group_key = $this->getRevisionActionGroupKey();
         $field->setCommentActionGroupKey($group_key);
+
+        // Currently, every revision action conflicts with every other
+        // revision action: for example, you can not simultaneously Accept and
+        // Reject a revision.
+
+        // Under some configurations, some combinations of actions are sort of
+        // technically permissible. For example, you could reasonably Reject
+        // and Abandon a revision if "anyone can abandon anything" is enabled.
+
+        // It's not clear that these combinations are actually useful, so just
+        // keep things simple for now.
+        $field->setActionConflictKey('revision.action');
       }
     }
 

src/applications/transactions/commentaction/PhabricatorEditEngineCommentAction.php

@@ -8,6 +8,7 @@ abstract class PhabricatorEditEngineCommentAction extends Phobject {
   private $initialValue;
   private $order;
   private $groupKey;
+  private $conflictKey;
 
   abstract public function getPHUIXControlType();
   abstract public function getPHUIXControlSpecification();
@@ -30,6 +31,15 @@ abstract class PhabricatorEditEngineCommentAction extends Phobject {
     return $this->groupKey;
   }
 
+  public function setConflictKey($conflict_key) {
+    $this->conflictKey = $conflict_key;
+    return $this;
+  }
+
+  public function getConflictKey() {
+    return $this->conflictKey;
+  }
+
   public function setLabel($label) {
     $this->label = $label;
     return $this;

src/applications/transactions/editfield/PhabricatorApplyEditField.php

@@ -4,6 +4,7 @@ final class PhabricatorApplyEditField
   extends PhabricatorEditField {
 
   private $actionDescription;
+  private $actionConflictKey;
 
   protected function newControl() {
     return null;
@@ -18,6 +19,15 @@ final class PhabricatorApplyEditField
     return $this->actionDescription;
   }
 
+  public function setActionConflictKey($action_conflict_key) {
+    $this->actionConflictKey = $action_conflict_key;
+    return $this;
+  }
+
+  public function getActionConflictKey() {
+    return $this->actionConflictKey;
+  }
+
   protected function newHTTPParameterType() {
     return new AphrontBoolHTTPParameterType();
   }
@@ -34,7 +44,8 @@ final class PhabricatorApplyEditField
 
   protected function newCommentAction() {
     return id(new PhabricatorEditEngineStaticCommentAction())
-      ->setDescription($this->getActionDescription());
+      ->setDescription($this->getActionDescription())
+      ->setConflictKey($this->getActionConflictKey());
   }
 
 }

src/applications/transactions/view/PhabricatorApplicationTransactionCommentView.php

@@ -301,6 +301,7 @@ class PhabricatorApplicationTransactionCommentView extends AphrontView {
           'spec' => $comment_action->getPHUIXControlSpecification(),
           'initialValue' => $comment_action->getInitialValue(),
           'groupKey' => $comment_action->getGroupKey(),
+          'conflictKey' => $comment_action->getConflictKey(),
         );
 
         $type_map[$key] = $comment_action;