fix: Adding FastBuffer extension methods for multiple instantiations of a generic type causes runtime errors [MTT-3063] (#2142)

Fixed RPC codegen failing to choose the correct extension methods for FastBufferReader and FastBufferWriter when the parameters were a generic type (i.e., List<int>) and extensions for multiple instantiations of that type have been defined (i.e., List<int> and List<string>)

Author: ShadauxCat

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -7,6 +7,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).
 
+## [Unreleased]
+
+### Fixed
+
+- Fixed RPC codegen failing to choose the correct extension methods for FastBufferReader and FastBufferWriter when the parameters were a generic type (i.e., List<int>) and extensions for multiple instantiations of that type have been defined (i.e., List<int> and List<string>) (#2142)
+
 ## [1.0.1] - 2022-08-23
 
 ### Changed

com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs

@@ -669,7 +669,7 @@ private bool GetWriteMethodForParameter(TypeReference paramType, out MethodRefer
                     {
                         if (parameters[1].IsIn)
                         {
-                            if (parameters[1].ParameterType.Resolve() == paramType.MakeByReferenceType().Resolve() &&
+                            if (((ByReferenceType)parameters[1].ParameterType).ElementType.FullName == paramType.FullName &&
                                 ((ByReferenceType)parameters[1].ParameterType).ElementType.IsArray == paramType.IsArray)
                             {
                                 methodRef = method;
@@ -679,8 +679,7 @@ private bool GetWriteMethodForParameter(TypeReference paramType, out MethodRefer
                         }
                         else
                         {
-
-                            if (parameters[1].ParameterType.Resolve() == paramType.Resolve() &&
+                            if (parameters[1].ParameterType.FullName == paramType.FullName &&
                                 parameters[1].ParameterType.IsArray == paramType.IsArray)
                             {
                                 methodRef = method;
@@ -813,7 +812,7 @@ private bool GetReadMethodForParameter(TypeReference paramType, out MethodRefere
                     var parameters = method.Resolve().Parameters;
                     if (method.Name == k_ReadValueMethodName &&
                         parameters[1].IsOut &&
-                        parameters[1].ParameterType.Resolve() == paramType.MakeByReferenceType().Resolve() &&
+                        ((ByReferenceType)parameters[1].ParameterType).ElementType.FullName == paramType.FullName &&
                         ((ByReferenceType)parameters[1].ParameterType).ElementType.IsArray == paramType.IsArray)
                     {
                         methodRef = method;