fix: Ensure DisconnectReason remains parsable (#3766)

Author: EmandM

com.unity.netcode.gameobjects/Runtime/Connection/NetworkConnectionManager.cs

@@ -113,36 +113,21 @@ public sealed class NetworkConnectionManager
         /// client that disconnected. It is recommended to copy the message to some other property or field when
         /// <see cref="OnClientDisconnectCallback"/> is invoked.
         /// </remarks>
-        public string DisconnectReason
-        {
-            get
-            {
-                // For in-frequent event driven invocations, a method within a getter
-                // is "generally ok".
-                return GetDisconnectReason();
-            }
-            internal set
-            {
-                m_DisconnectReason = value;
-            }
-        }
+        public string DisconnectReason => GetDisconnectReason(); // fine as function because this call is infrequent
 
         /// <summary>
-        /// Returns the conbined result of the locally applied <see cref="DisconnectReason"/> and the
-        /// server applied <see cref="ServerDisconnectReason"/>.
-        /// - If both values are empty or null, then it returns <see cref="string.Empty"/>.
-        /// - If either value is valid, then it returns that <see cref="string"/> value.
-        /// - If both values are valid, then it returns <see cref="DisconnectReason"/> followed by a
-        /// new line and then <see cref="ServerDisconnectReason"/>.
+        /// Gets the reason for why this client was disconnected if exists.
         /// </summary>
-        /// <returns>A disconnect reason, if any.</returns>
+        /// <returns><see cref="ServerDisconnectReason"/> disconnect reason if it exists, otherwise <see cref="m_DisconnectReason"/>.</returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        internal string GetDisconnectReason(string header = null)
+        internal string GetDisconnectReason()
         {
-            var disconnectReason = string.IsNullOrEmpty(m_DisconnectReason) ? string.Empty : m_DisconnectReason;
-            var serverDisconnectReason = string.IsNullOrEmpty(ServerDisconnectReason) ? string.Empty : $"\n{ServerDisconnectReason}";
-            var headerInfo = string.IsNullOrEmpty(header) ? string.Empty : header;
-            return $"{headerInfo}{disconnectReason}{serverDisconnectReason}";
+            // TODO: fix this properly
+            if (!string.IsNullOrEmpty(ServerDisconnectReason))
+            {
+                return ServerDisconnectReason;
+            }
+            return m_DisconnectReason;
         }
 
         /// <summary>
@@ -590,7 +575,8 @@ private void GenerateDisconnectInformation(ulong clientId, ulong transportClient
 
             if (NetworkLog.CurrentLogLevel <= LogLevel.Developer)
             {
-                NetworkLog.LogInfo($"{DisconnectReason}");
+                var serverDisconnectReason = string.IsNullOrEmpty(ServerDisconnectReason) ? string.Empty : $"\n{ServerDisconnectReason}";
+                NetworkLog.LogInfo($"{m_DisconnectReason}{serverDisconnectReason}");
             }
         }
 

com.unity.netcode.gameobjects/Runtime/Messaging/DisconnectReasonMessage.cs renamed to com.unity.netcode.gameobjects/Runtime/Messaging/Messages/DisconnectReasonMessage.cs

@@ -10,7 +10,7 @@ public void Serialize(FastBufferWriter writer, int targetVersion)
         {
             string reasonSent = Reason ?? string.Empty;
 
-            // Since we don't send a ConnectionApprovedMessage, the version for this message is encded with the message itself.
+            // Since we don't send a ConnectionApprovedMessage, the version for this message is encoded with the message itself.
             // However, note that we HAVE received a ConnectionRequestMessage, so we DO have a valid targetVersion on this side of things.
             // We just have to make sure the receiving side knows what version we sent it, since whoever has the higher version number is responsible for versioning and they may be the one with the higher version number.
             BytePacker.WriteValueBitPacked(writer, Version);