From 872b254db592c701838b9409c828418529963f82 Mon Sep 17 00:00:00 2001
From: Florian Schmaus <flo@geekplace.eu>
Date: Mon, 30 Jan 2017 21:01:56 +0100
Subject: [PATCH] sendStanzaWithResponseCallback: Ensure exactly one callback
 is called

---
 .../org/jivesoftware/smack/AbstractXMPPConnection.java     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
index bdfa066a2..2e8f5a5c5 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
@@ -1494,7 +1494,12 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         final StanzaListener packetListener = new StanzaListener() {
             @Override
             public void processStanza(Stanza packet) throws NotConnectedException, InterruptedException {
-                removeAsyncStanzaListener(this);
+                boolean removed = removeAsyncStanzaListener(this);
+                if (!removed) {
+                    // We lost a race against the "no response" handling runnable. Avoid calling the callback, as the
+                    // exception callback will be invoked (if any).
+                    return;
+                }
                 try {
                     XMPPErrorException.ifHasErrorThenThrow(packet);
                     callback.processStanza(packet);