From 2170d80b157933fb4fa36bf0cc66f3780efdf0f1 Mon Sep 17 00:00:00 2001
From: Artur Signell <artur@vaadin.com>
Date: Thu, 6 Aug 2015 11:13:21 +0300
Subject: [PATCH] Guard against disconnect() being called twice (#15263)

Change-Id: I9fa8b5659b4079684f3348c18a6e246914ee8447
---
 .../server/communication/AtmospherePushConnection.java     | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/server/src/com/vaadin/server/communication/AtmospherePushConnection.java b/server/src/com/vaadin/server/communication/AtmospherePushConnection.java
index 357278f411..a45d9aa059 100644
--- a/server/src/com/vaadin/server/communication/AtmospherePushConnection.java
+++ b/server/src/com/vaadin/server/communication/AtmospherePushConnection.java
@@ -274,6 +274,13 @@ public class AtmospherePushConnection implements PushConnection {
     public void disconnect() {
         assert isConnected();
 
+        if (resource == null) {
+            // Already disconnected. Should not happen but if it does, we don't
+            // want to cause NPEs
+            getLogger()
+                    .fine("AtmospherePushConnection.disconnect() called twice, this should not happen");
+            return;
+        }
         if (resource.isResumed()) {
             // This can happen for long polling because of
             // http://dev.vaadin.com/ticket/16919
-- 
2.39.5