Index: src/applications/maniphest/controller/ManiphestTaskEditController.php
===================================================================
--- src/applications/maniphest/controller/ManiphestTaskEditController.php
+++ src/applications/maniphest/controller/ManiphestTaskEditController.php
@@ -49,9 +49,24 @@
         $task->setTitle($request->getStr('title'));
 
         if ($can_edit_projects) {
-          $default_projects = $request->getStr('projects');
-          if ($default_projects) {
-            $task->setProjectPHIDs(explode(';', $default_projects));
+          $projects = $request->getStr('projects');
+          if ($projects) {
+            $default_projects = id(new PhabricatorProject())->loadAllWhere(
+              'name IN (%Ls)',
+              explode(';', $projects));
+            if ($default_projects) {
+              $task->setProjectPHIDs(mpull($default_projects, 'getPHID'));
+            }
+          }
+        }
+
+        if ($can_edit_priority) {
+          $priority = $request->getInt('priority');
+          if ($priority !== null) {
+            $priority_map = ManiphestTaskPriority::getTaskPriorityMap();
+            if (isset($priority_map[$priority])) {
+                $task->setPriority($priority);
+            }
           }
         }