Add null check for previous rider when re-assigning rider. #621

src/Service/JobOrderHandler/ResqJobOrderHandler.php

@@ -1475,10 +1475,12 @@ class ResqJobOrderHandler implements JobOrderHandlerInterface
 
             // need to unset first rider's current job order
             $old_rider = $obj->getRider();
+            if ($old_rider != null)
+            {
                 $old_rider->setCurrentJobOrder();
-
                 // set available flag for first rider
                 $old_rider->setAvailable(true);
+            }
 
             // coordinates
             $point = new Point($req->request->get('coord_lng'), $req->request->get('coord_lat'));