Fix an issue with viewing an empty board with milestone columns

Summary:
Ref T10010.

  - Viewing an empty board with milestone columns did a meaningless edge query. Don't do that.
  - When creating the first milestone of a parent, force the indexing engine to rematerialize it inline. This sets `hasMilestones` properly. Otherwise, the daemons may take some time to fix this in the indexer.

Test Plan:
  - Viewed an empty board of a project with a milestone.
  - Viewed a normal board.
  - Created the first milestone of a project with a big queue of daemons, saw project state immediately fully reflect the project having milestones.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10010

Differential Revision: https://secure.phabricator.com/D15206

src/applications/project/editor/PhabricatorProjectTransactionEditor.php

@@ -631,6 +631,7 @@ final class PhabricatorProjectTransactionEditor
           }
           break;
         case PhabricatorProjectTransaction::TYPE_PARENT:
+        case PhabricatorProjectTransaction::TYPE_MILESTONE:
           $materialize = true;
           $new_parent = $object->getParentProject();
           break;
@@ -669,6 +670,11 @@ final class PhabricatorProjectTransactionEditor
         ->rematerialize($object);
     }
 
+    if ($new_parent) {
+      id(new PhabricatorProjectsMembershipIndexEngineExtension())
+        ->rematerialize($new_parent);
+    }
+
     return parent::applyFinalEffects($object, $xactions);
   }
 

src/applications/project/engine/PhabricatorBoardLayoutEngine.php

@@ -435,7 +435,7 @@ final class PhabricatorBoardLayoutEngine extends Phobject {
 
     // If we have proxies, we need to force cards into the correct proxy
     // columns.
-    if ($proxy_map) {
+    if ($proxy_map && $object_phids) {
       $edge_query = id(new PhabricatorEdgeQuery())
         ->withSourcePHIDs($object_phids)
         ->withEdgeTypes(