From 6c8f85afe9dc614c1d3aa02f2e935c0549182ddc Mon Sep 17 00:00:00 2001
From: JanEggers <jan.eggers@ferag.com>
Date: Sat, 9 Sep 2017 02:48:13 +0200
Subject: [PATCH 1/3] fixed invalid operation exception

---
 MQTTnet.Core/Client/MqttPacketDispatcher.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MQTTnet.Core/Client/MqttPacketDispatcher.cs b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
index 0784e8a..befca59 100644
--- a/MQTTnet.Core/Client/MqttPacketDispatcher.cs
+++ b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
@@ -41,7 +41,7 @@ namespace MQTTnet.Core.Client
             {
                 if (packetAwaiter.PacketSelector(packet))
                 {
-                    packetAwaiter.SetResult(packet);
+                    packetAwaiter.TrySetResult(packet);
                     packetDispatched = true;
                     break;
                 }

From 861efa5e75ba715c2fc6158b82b294b8149f01a5 Mon Sep 17 00:00:00 2001
From: JanEggers <jan.eggers@ferag.com>
Date: Sat, 9 Sep 2017 08:14:53 +0200
Subject: [PATCH 2/3] dont add the same package twice to _receivedPackets

---
 MQTTnet.Core/Client/MqttPacketDispatcher.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MQTTnet.Core/Client/MqttPacketDispatcher.cs b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
index befca59..da8b1fa 100644
--- a/MQTTnet.Core/Client/MqttPacketDispatcher.cs
+++ b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
@@ -10,7 +10,7 @@ namespace MQTTnet.Core.Client
     public class MqttPacketDispatcher
     {
         private readonly object _syncRoot = new object();
-        private readonly List<MqttBasePacket> _receivedPackets = new List<MqttBasePacket>();
+        private readonly HashSet<MqttBasePacket> _receivedPackets = new HashSet<MqttBasePacket>();
         private readonly List<MqttPacketAwaiter> _packetAwaiters = new List<MqttPacketAwaiter>();
 
         public async Task<MqttBasePacket> WaitForPacketAsync(Func<MqttBasePacket, bool> selector, TimeSpan timeout)

From 80a6e6809cf4ba56394a6fe20b9078d73ae78215 Mon Sep 17 00:00:00 2001
From: JanEggers <jan.eggers@ferag.com>
Date: Sun, 10 Sep 2017 12:16:44 +0200
Subject: [PATCH 3/3] use same lockobject everywhere to prevent raceconditions

---
 MQTTnet.Core/Client/MqttPacketDispatcher.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MQTTnet.Core/Client/MqttPacketDispatcher.cs b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
index da8b1fa..aba050d 100644
--- a/MQTTnet.Core/Client/MqttPacketDispatcher.cs
+++ b/MQTTnet.Core/Client/MqttPacketDispatcher.cs
@@ -71,7 +71,7 @@ namespace MQTTnet.Core.Client
 
         private List<MqttPacketAwaiter> GetPacketAwaiters()
         {
-            lock (_packetAwaiters)
+            lock (_syncRoot)
             {
                 return new List<MqttPacketAwaiter>(_packetAwaiters);
             }