Fix ResXNullRef type handling

System.Resources.NetStandard/ResXDataNode.cs

@@ -158,6 +158,11 @@ private void InitializeDataNode(string basePath)
                     }
                 }
             }
+
+            if (nodeType != null && nodeType.Equals(typeof(ResXNullRef)))
+            {
+                value = new ResXNullRef();
+            }
         }
 
         /// <summary>
@@ -619,11 +624,16 @@ public string GetValueTypeName(AssemblyName[] names)
         /// </summary>
         public object GetValue(ITypeResolutionService typeResolver)
         {
+            if (value is ResXNullRef)
+            {
+                return null;
+            }
+
             if (value != null)
             {
                 return value;
             }
-
+            
             object result = null;
             if (FileRefFullPath != null)
             {
@@ -962,6 +972,13 @@ public Type GetType(string name, bool throwOnError, bool ignoreCase)
                 result = typeof(ResXFileRef);
                 return result;
             }
+
+            // Replace the WinForms ResXNullRef with the copy in this library
+            if (name.StartsWith(ResXConstants.ResXNullRef_TypeNameAndAssembly, StringComparison.Ordinal))
+            {
+                result = typeof(ResXNullRef);
+                return result;
+            }
 
             // Missed in cache, try to resolve the type from the reference assemblies.
             if (name.IndexOf(',') != -1)

System.Resources.NetStandard/ResxConstants.cs

@@ -10,5 +10,8 @@ internal class ResXConstants
 
         public const string ResxFileRefTypeInfo = "System.Resources.ResXFileRef, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089";
         public const string ResxFileRef_TypeNameAndAssembly = "System.Resources.ResXFileRef, System.Windows.Forms";
+
+        public const string ResxNullRefTypeInfo = "System.Resources.ResXNullRef, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089";
+        public const string ResXNullRef_TypeNameAndAssembly = "System.Resources.ResXNullRef, System.Windows.Forms";
     }
 }

System.Resources.NetStandard/WinformsTypeMappers.cs

@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace System.Resources.NetStandard
+namespace System.Resources.NetStandard
 {
     internal static class WinformsTypeMappers
     {
@@ -12,13 +8,14 @@ public static Func<Type, string> InterceptWinformsTypes(Func<Type,string> typeNa
             {
                 if (type.AssemblyQualifiedName == typeof(ResXFileRef).AssemblyQualifiedName)
                 {
-                    return NetStandard.ResXConstants.ResxFileRefTypeInfo;
+                    return ResXConstants.ResxFileRefTypeInfo;
                 }
-                else
+                else if (type.AssemblyQualifiedName == typeof(ResXNullRef).AssemblyQualifiedName)
                 {
-                    if (typeNameConverter != null) return typeNameConverter(type);
-                    else return null;
+                    return ResXConstants.ResxNullRefTypeInfo;
                 }
+                else if (typeNameConverter != null) return typeNameConverter(type);
+                else return null;
             };
         }