fix: Avoid duplicate RPC invocation on host (#2834)

Host acts as both client and server.
Both the client target and the server target points to same instance
This results in two invocations on the host which is not expected
Checking that the server is host and skipping the RpcTarget invocation we avoid this situation

com.unity.netcode.gameobjects/Runtime/Messaging/RpcTargets/NotMeRpcTarget.cs

@@ -49,6 +49,10 @@ namespace Unity.Netcode
                     {
                         continue;
                     }
+                    if (clientId == NetworkManager.ServerClientId)
+                    {
+                        continue;
+                    }
                     m_GroupSendTarget.Add(clientId);
                 }
             }

com.unity.netcode.gameobjects/Runtime/Messaging/RpcTargets/NotOwnerRpcTarget.cs

@@ -40,6 +40,10 @@ namespace Unity.Netcode
                     {
                         continue;
                     }
+                    if (clientId == NetworkManager.ServerClientId)
+                    {
+                        continue;
+                    }
                     if (clientId == behaviour.NetworkManager.LocalClientId)
                     {
                         m_LocalSendRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
@@ -57,6 +61,10 @@ namespace Unity.Netcode
                     {
                         continue;
                     }
+                    if (clientId == NetworkManager.ServerClientId)
+                    {
+                        continue;
+                    }
                     if (clientId == behaviour.NetworkManager.LocalClientId)
                     {
                         m_LocalSendRpcTarget.Send(behaviour, ref message, delivery, rpcParams);

com.unity.netcode.gameobjects/Tests/Runtime/UniversalRpcTests.cs

@@ -24,6 +24,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
         public string Received = string.Empty;
         public Tuple<int, bool, float, string> ReceivedParams = null;
         public ulong ReceivedFrom = ulong.MaxValue;
+        public int ReceivedCount;
 
         public void OnRpcReceived()
         {
@@ -32,6 +33,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
 
             var currentMethod = sf.GetMethod();
             Received = currentMethod.Name;
+            ReceivedCount++;
         }
         public void OnRpcReceivedWithParams(int a, bool b, float f, string s)
         {
@@ -40,6 +42,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
 
             var currentMethod = sf.GetMethod();
             Received = currentMethod.Name;
+            ReceivedCount++;
             ReceivedParams = new Tuple<int, bool, float, string>(a, b, f, s);
         }
 
@@ -496,6 +499,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
             foreach (var obj in Object.FindObjectsByType<UniversalRpcNetworkBehaviour>(FindObjectsSortMode.None))
             {
                 obj.Received = string.Empty;
+                obj.ReceivedCount = 0;
                 obj.ReceivedParams = null;
                 obj.ReceivedFrom = ulong.MaxValue;
             }
@@ -528,10 +532,11 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
             return m_PlayerNetworkObjects[onClient][ownerClientId].GetComponent<UniversalRpcNetworkBehaviour>();
         }
 
-        protected void VerifyLocalReceived(ulong objectOwner, ulong sender, string name, bool verifyReceivedFrom)
+        protected void VerifyLocalReceived(ulong objectOwner, ulong sender, string name, bool verifyReceivedFrom, int expectedReceived = 1)
         {
             var obj = GetPlayerObject(objectOwner, sender);
             Assert.AreEqual(name, obj.Received);
+            Assert.That(obj.ReceivedCount, Is.EqualTo(expectedReceived));
             Assert.IsNull(obj.ReceivedParams);
             if (verifyReceivedFrom)
             {
@@ -543,6 +548,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
         {
             var obj = GetPlayerObject(objectOwner, sender);
             Assert.AreEqual(name, obj.Received);
+            Assert.That(obj.ReceivedCount, Is.EqualTo(1));
             Assert.IsNotNull(obj.ReceivedParams);
             Assert.AreEqual(i, obj.ReceivedParams.Item1);
             Assert.AreEqual(b, obj.ReceivedParams.Item2);
@@ -556,17 +562,18 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
             {
                 UniversalRpcNetworkBehaviour playerObject = GetPlayerObject(objectOwner, client);
                 Assert.AreEqual(string.Empty, playerObject.Received);
+                Assert.That(playerObject.ReceivedCount, Is.EqualTo(0));
                 Assert.IsNull(playerObject.ReceivedParams);
             }
         }
 
-        protected void VerifyRemoteReceived(ulong objectOwner, ulong sender, string message, ulong[] receivedBy, bool verifyReceivedFrom, bool waitForMessages = true)
+        protected void VerifyRemoteReceived(ulong objectOwner, ulong sender, string message, ulong[] receivedBy, bool verifyReceivedFrom, bool waitForMessages = true, int expectedReceived = 1)
         {
             foreach (var client in receivedBy)
             {
                 if (client == sender)
                 {
-                    VerifyLocalReceived(objectOwner, sender, message, verifyReceivedFrom);
+                    VerifyLocalReceived(objectOwner, sender, message, verifyReceivedFrom, expectedReceived);
 
                     break;
                 }
@@ -628,6 +635,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
             {
                 UniversalRpcNetworkBehaviour playerObject = GetPlayerObject(objectOwner, client);
                 Assert.AreEqual(message, playerObject.Received);
+                Assert.That(playerObject.ReceivedCount, Is.EqualTo(expectedReceived));
                 Assert.IsNull(playerObject.ReceivedParams);
                 if (verifyReceivedFrom)
                 {
@@ -701,6 +709,7 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
             {
                 UniversalRpcNetworkBehaviour playerObject = GetPlayerObject(objectOwner, client);
                 Assert.AreEqual(message, playerObject.Received);
+                Assert.That(playerObject.ReceivedCount, Is.EqualTo(1));
 
                 Assert.IsNotNull(playerObject.ReceivedParams);
                 Assert.AreEqual(i, playerObject.ReceivedParams.Item1);
@@ -1636,17 +1645,20 @@ namespace Unity.Netcode.RuntimeTests.UniversalRpcTests
 
             VerifyNotReceived(NetworkManager.ServerClientId, s_ClientIds);
 
-            for (var i = 0; i < 10; ++i)
+            var clientListExpected = 1;
+            var serverListExpected = 2;
+            for (var i = 1; i <= 10; ++i)
             {
                 WaitForMessageReceivedWithTimeTravel<RpcMessage>(clientList);
-                VerifyRemoteReceived(NetworkManager.ServerClientId, NetworkManager.ServerClientId, nameof(UniversalRpcNetworkBehaviour.MutualRecursionClientRpc), clientIdArray, false, false);
+                VerifyRemoteReceived(NetworkManager.ServerClientId, NetworkManager.ServerClientId, nameof(UniversalRpcNetworkBehaviour.MutualRecursionClientRpc), clientIdArray, false, false, clientListExpected);
                 VerifyNotReceived(NetworkManager.ServerClientId, serverIdArray);
+                clientListExpected *= 2;
 
                 Clear();
-
                 WaitForMessageReceivedWithTimeTravel<RpcMessage>(serverList);
-                VerifyRemoteReceived(NetworkManager.ServerClientId, NetworkManager.ServerClientId, nameof(UniversalRpcNetworkBehaviour.MutualRecursionServerRpc), serverIdArray, false, false);
+                VerifyRemoteReceived(NetworkManager.ServerClientId, NetworkManager.ServerClientId, nameof(UniversalRpcNetworkBehaviour.MutualRecursionServerRpc), serverIdArray, false, false, serverListExpected);
                 VerifyNotReceived(NetworkManager.ServerClientId, clientIdArray);
+                serverListExpected *= 2;
 
                 Clear();
             }