1846 server mqttserverstopasync doesnt indicate correct reason (#1872)

Source/MQTTnet/Formatter/MqttDisconnectPacketFactory.cs

@@ -5,45 +5,107 @@
 using MQTTnet.Client;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
+using MQTTnet.Server;
+using MQTTnet.Server.Disconnecting;
 
 namespace MQTTnet.Formatter
 {
     public sealed class MqttDisconnectPacketFactory
     {
-        readonly MqttDisconnectPacket _normalDisconnection = new MqttDisconnectPacket
+        static readonly MqttDisconnectPacket DefaultNormalDisconnection = new MqttDisconnectPacket
         {
-            ReasonCode = MqttDisconnectReasonCode.NormalDisconnection
+            ReasonCode = MqttDisconnectReasonCode.NormalDisconnection,
+            UserProperties = null,
+            ReasonString = null,
+            ServerReference = null,
+            SessionExpiryInterval = 0
+        };
+
+        static readonly MqttDisconnectPacket DefaultServerShuttingDown = new MqttDisconnectPacket
+        {
+            ReasonCode = MqttDisconnectReasonCode.ServerShuttingDown,
+            UserProperties = null,
+            ReasonString = null,
+            ServerReference = null,
+            SessionExpiryInterval = 0
+        };
+
+        static readonly MqttDisconnectPacket DefaultUnspecifiedError = new MqttDisconnectPacket
+        {
+            ReasonCode = MqttDisconnectReasonCode.UnspecifiedError,
+            UserProperties = null,
+            ReasonString = null,
+            ServerReference = null,
+            SessionExpiryInterval = 0
         };
 
         public MqttDisconnectPacket Create(MqttDisconnectReasonCode reasonCode)
         {
             if (reasonCode == MqttDisconnectReasonCode.NormalDisconnection)
             {
-                return _normalDisconnection;
+                return DefaultNormalDisconnection;
+            }
+
+            if (reasonCode == MqttDisconnectReasonCode.ServerShuttingDown)
+            {
+                return DefaultServerShuttingDown;
+            }
+
+            if (reasonCode == MqttDisconnectReasonCode.UnspecifiedError)
+            {
+                return DefaultUnspecifiedError;
             }
 
             return new MqttDisconnectPacket
             {
-                ReasonCode = reasonCode
+                ReasonCode = reasonCode,
+                UserProperties = null,
+                ReasonString = null,
+                ServerReference = null,
+                SessionExpiryInterval = 0
+            };
+        }
+
+        public MqttDisconnectPacket Create(MqttServerStopOptions serverStopOptions)
+        {
+            if (serverStopOptions == null)
+            {
+                return DefaultServerShuttingDown;
+            }
+
+            return Create(serverStopOptions.DefaultClientDisconnectOptions);
+        }
+
+        public MqttDisconnectPacket Create(MqttServerClientDisconnectOptions clientDisconnectOptions)
+        {
+            if (clientDisconnectOptions == null)
+            {
+                return DefaultNormalDisconnection;
+            }
+
+            return new MqttDisconnectPacket
+            {
+                ReasonCode = clientDisconnectOptions.ReasonCode,
+                UserProperties = clientDisconnectOptions.UserProperties,
+                ReasonString = clientDisconnectOptions.ReasonString,
+                ServerReference = clientDisconnectOptions.ServerReference,
+                SessionExpiryInterval = 0 // TODO: Not yet supported!
             };
         }
 
         public MqttDisconnectPacket Create(MqttClientDisconnectOptions clientDisconnectOptions)
         {
-            var packet = new MqttDisconnectPacket();
-
             if (clientDisconnectOptions == null)
             {
-                packet.ReasonCode = MqttDisconnectReasonCode.NormalDisconnection;
-            }
-            else
-            {
-                packet.ReasonCode = (MqttDisconnectReasonCode)clientDisconnectOptions.Reason;
-                packet.UserProperties = clientDisconnectOptions.UserProperties;
-                packet.SessionExpiryInterval = clientDisconnectOptions.SessionExpiryInterval;
+                return DefaultNormalDisconnection;
             }
 
-            return packet;
+            return new MqttDisconnectPacket
+            {
+                ReasonCode = (MqttDisconnectReasonCode)clientDisconnectOptions.Reason,
+                UserProperties = clientDisconnectOptions.UserProperties,
+                SessionExpiryInterval = clientDisconnectOptions.SessionExpiryInterval
+            };
         }
     }
 }