Fix/migration cleanup lost changes (#417)

* fix: Add bug fixes wich where in master mlapi but didn't get migrated to develop.

* fix: Add backk soft sync objects handling which was removed during migration

* refactor: moved diffed scene object cleanup code to spawn manager

Co-authored-by: Matt Walsh <matt.walsh@unity3d.com>
Co-authored-by: mattwalsh-unity <69258106+mattwalsh-unity@users.noreply.github.com>

Author: LukeStampfli

com.unity.multiplayer.mlapi/Runtime/Configuration/NetworkConfig.cs

@@ -336,7 +336,7 @@ public ulong GetConfig(bool cache = true)
                     writer.WriteUInt16Packed(ProtocolVersion);
                     writer.WriteString(MLAPIConstants.MLAPI_PROTOCOL_VERSION);
 
-                    if (!AllowRuntimeSceneChanges)
+                    if (EnableSceneManagement && !AllowRuntimeSceneChanges)
                     {
                         for (int i = 0; i < RegisteredScenes.Count; i++)
                         {

com.unity.multiplayer.mlapi/Runtime/Messaging/InternalMessageHandler.cs

@@ -344,6 +344,8 @@ void DelayedSpawnAction(Stream continuationStream)
                             }
                         }
 
+                        SpawnManager.CleanDiffedSceneObjects();
+
                         NetworkingManager.Singleton.IsConnectedClient = true;
 
                         NetworkingManager.Singleton.InvokeOnClientConnectedCallback(NetworkingManager.Singleton.LocalClientId);

com.unity.multiplayer.mlapi/Runtime/Serialization/BitWriter.cs

@@ -52,11 +52,14 @@ internal Stream GetStream()
         /// <param name="value">The object to write</param>
         public void WriteObjectPacked(object value)
         {
-            if (value == null || value.GetType().IsNullable())
+            // Check unitys custom null checks
+            bool isNull = value == null || (value is UnityEngine.Object && ((UnityEngine.Object)value) == null);
+
+            if (isNull || value.GetType().IsNullable())
             {
-                WriteBool(value == null);
+                WriteBool(isNull);
 
-                if (value == null)
+                if (isNull)
                 {
                     return;
                 }

com.unity.multiplayer.mlapi/Runtime/Spawning/SpawnManager.cs

@@ -596,6 +596,25 @@ internal static void DestroySceneObjects()
             }
         }
 
+        internal static void CleanDiffedSceneObjects()
+        {
+            // Clean up the diffed scene objects. I.E scene objects that have been destroyed
+            if (pendingSoftSyncObjects.Count > 0)
+            {
+                List<NetworkedObject> objectsToDestroy = new List<NetworkedObject>();
+
+                foreach (KeyValuePair<ulong, NetworkedObject> pair in pendingSoftSyncObjects)
+                {
+                    objectsToDestroy.Add(pair.Value);
+                }
+
+                for (int i = 0; i < objectsToDestroy.Count; i++)
+                {
+                    MonoBehaviour.Destroy(objectsToDestroy[i].gameObject);
+                }
+            }
+        }
+
         internal static void ServerSpawnSceneObjectsOnStartSweep()
         {
             NetworkedObject[] networkedObjects = MonoBehaviour.FindObjectsOfType<NetworkedObject>();