From 888e1797d72451b20ce03e8841438d25f2ae0d24 Mon Sep 17 00:00:00 2001
From: JanEggers <jan.Eggers@ferag.com>
Date: Mon, 15 Apr 2019 14:04:21 +0200
Subject: [PATCH] fixed cherry pick

---
 Source/MQTTnet.AspnetCore/ReaderExtensions.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/MQTTnet.AspnetCore/ReaderExtensions.cs b/Source/MQTTnet.AspnetCore/ReaderExtensions.cs
index cb347c4c..e2cb1c44 100644
--- a/Source/MQTTnet.AspnetCore/ReaderExtensions.cs
+++ b/Source/MQTTnet.AspnetCore/ReaderExtensions.cs
@@ -42,7 +42,7 @@ namespace MQTTnet.AspNetCore
 
             var receivedMqttPacket = new ReceivedMqttPacket(fixedheader, reader, buffer.Length + 2);
 
-            if (!formatter.ProtocolVersion.HasValue)
+            if (formatter.ProtocolVersion == MqttProtocolVersion.Unknown)
             {
                 formatter.DetectProtocolVersion(receivedMqttPacket);
             }