com.unity.netcode.gameobjects@1.5.1

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).

## [1.5.1] - 2023-06-07

### Added

- Added support for serializing `NativeArray<>` and `NativeList<>` in `FastBufferReader`/`FastBufferWriter`, `BufferSerializer`, `NetworkVariable`, and RPCs. (To use `NativeList<>`, add `UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT` to your Scripting Define Symbols in `Project Settings > Player`) (#2375)
- The location of the automatically-created default network prefab list can now be configured (#2544)
- Added: Message size limits (max single message and max fragmented message) can now be set using NetworkManager.MaximumTransmissionUnitSize and NetworkManager.MaximumFragmentedMessageSize for transports that don't work with the default values (#2530)
- Added `NetworkObject.SpawnWithObservers` property (default is true) that when set to false will spawn a `NetworkObject` with no observers and will not be spawned on any client until `NetworkObject.NetworkShow` is invoked. (#2568)

### Fixed

- Fixed: Fixed a null reference in codegen in some projects (#2581)
- Fixed issue where the `OnClientDisconnected` client identifier was incorrect after a pending client connection was denied. (#2569)
- Fixed warning "Runtime Network Prefabs was not empty at initialization time." being erroneously logged when no runtime network prefabs had been added (#2565)
- Fixed issue where some temporary debug console logging was left in a merged PR. (#2562)
- Fixed the "Generate Default Network Prefabs List" setting not loading correctly and always reverting to being checked. (#2545)
- Fixed issue where users could not use NetworkSceneManager.VerifySceneBeforeLoading to exclude runtime generated scenes from client synchronization. (#2550)
- Fixed missing value on `NetworkListEvent` for `EventType.RemoveAt` events.  (#2542,#2543)
- Fixed issue where parenting a NetworkTransform under a transform with a scale other than Vector3.one would result in incorrect values on non-authoritative instances. (#2538)
- Fixed issue where a server would include scene migrated and then despawned NetworkObjects to a client that was being synchronized. (#2532)
- Fixed the inspector throwing exceptions when attempting to render `NetworkVariable`s of enum types. (#2529)
- Making a `NetworkVariable` with an `INetworkSerializable` type that doesn't meet the `new()` constraint will now create a compile-time error instead of an editor crash (#2528)
- Fixed Multiplayer Tools package installation docs page link on the NetworkManager popup. (#2526)
- Fixed an exception and error logging when two different objects are shown and hidden on the same frame (#2524)
- Fixed a memory leak in `UnityTransport` that occurred if `StartClient` failed. (#2518)
- Fixed issue where a client could throw an exception if abruptly disconnected from a network session with one or more spawned `NetworkObject`(s). (#2510)
- Fixed issue where invalid endpoint addresses were not being detected and returning false from NGO UnityTransport. (#2496)
- Fixed some errors that could occur if a connection is lost and the loss is detected when attempting to write to the socket. (#2495)

## Changed

- Adding network prefabs before NetworkManager initialization is now supported. (#2565)
- Connecting clients being synchronized now switch to the server's active scene before spawning and synchronizing NetworkObjects. (#2532)
- Updated `UnityTransport` dependency on `com.unity.transport` to 1.3.4. (#2533)
- Improved performance of NetworkBehaviour initialization by replacing reflection when initializing NetworkVariables with compile-time code generation, which should help reduce hitching during additive scene loads. (#2522)

Runtime/Configuration/NetworkPrefabs.cs

@@ -38,10 +38,15 @@ namespace Unity.Netcode
         [NonSerialized]
         private List<NetworkPrefab> m_Prefabs = new List<NetworkPrefab>();
 
+        [NonSerialized]
+        private List<NetworkPrefab> m_RuntimeAddedPrefabs = new List<NetworkPrefab>();
+
         private void AddTriggeredByNetworkPrefabList(NetworkPrefab networkPrefab)
         {
             if (AddPrefabRegistration(networkPrefab))
             {
+                // Don't add this to m_RuntimeAddedPrefabs
+                // This prefab is now in the PrefabList, so if we shutdown and initialize again, we'll pick it up from there.
                 m_Prefabs.Add(networkPrefab);
             }
         }
@@ -67,8 +72,6 @@ namespace Unity.Netcode
                 list.OnAdd -= AddTriggeredByNetworkPrefabList;
                 list.OnRemove -= RemoveTriggeredByNetworkPrefabList;
             }
-
-            NetworkPrefabsLists.Clear();
         }
 
         /// <summary>
@@ -77,13 +80,7 @@ namespace Unity.Netcode
         /// </summary>
         public void Initialize(bool warnInvalid = true)
         {
-            if (NetworkPrefabsLists.Count != 0 && m_Prefabs.Count > 0)
-            {
-                NetworkLog.LogWarning("Runtime Network Prefabs was not empty at initialization time. Network " +
-                    "Prefab registrations made before initialization will be replaced by NetworkPrefabsList.");
-                m_Prefabs.Clear();
-            }
-
+            m_Prefabs.Clear();
             foreach (var list in NetworkPrefabsLists)
             {
                 list.OnAdd += AddTriggeredByNetworkPrefabList;
@@ -93,7 +90,7 @@ namespace Unity.Netcode
             NetworkPrefabOverrideLinks.Clear();
             OverrideToNetworkPrefab.Clear();
 
-            var prefabs = NetworkPrefabsLists.Count != 0 ? new List<NetworkPrefab>() : m_Prefabs;
+            var prefabs = new List<NetworkPrefab>();
 
             if (NetworkPrefabsLists.Count != 0)
             {
@@ -126,6 +123,18 @@ namespace Unity.Netcode
                 }
             }
 
+            foreach (var networkPrefab in m_RuntimeAddedPrefabs)
+            {
+                if (AddPrefabRegistration(networkPrefab))
+                {
+                    m_Prefabs.Add(networkPrefab);
+                }
+                else
+                {
+                    removeList?.Add(networkPrefab);
+                }
+            }
+
             // Clear out anything that is invalid or not used
             if (removeList?.Count > 0)
             {
@@ -152,6 +161,7 @@ namespace Unity.Netcode
             if (AddPrefabRegistration(networkPrefab))
             {
                 m_Prefabs.Add(networkPrefab);
+                m_RuntimeAddedPrefabs.Add(networkPrefab);
                 return true;
             }
 
@@ -175,6 +185,7 @@ namespace Unity.Netcode
             }
 
             m_Prefabs.Remove(prefab);
+            m_RuntimeAddedPrefabs.Remove(prefab);
             OverrideToNetworkPrefab.Remove(prefab.TargetPrefabGlobalObjectIdHash);
             NetworkPrefabOverrideLinks.Remove(prefab.SourcePrefabGlobalObjectIdHash);
         }
@@ -203,6 +214,15 @@ namespace Unity.Netcode
                     return;
                 }
             }
+
+            for (int i = 0; i < m_RuntimeAddedPrefabs.Count; i++)
+            {
+                if (m_RuntimeAddedPrefabs[i].Prefab == prefab)
+                {
+                    Remove(m_RuntimeAddedPrefabs[i]);
+                    return;
+                }
+            }
         }
 
         /// <summary>