438387 - NullPointerException after ServletUpgradeResponse.sendForbidden

is called during WebSocketCreator.createWebSocket 

+ Adding NPE guard for error/forbidden/complete flows

jetty-websocket/websocket-servlet/src/main/java/org/eclipse/jetty/websocket/servlet/ServletUpgradeResponse.java

@@ -58,9 +58,14 @@ public class ServletUpgradeResponse extends UpgradeResponse
     }
 
     public boolean isCommitted()
+    {
+        if (response != null)
         {
             return response.isCommitted();
         }
+        // True in all other cases
+        return true;
+    }
 
     public boolean isExtensionsNegotiated()
     {