-Fix passed in JsonConverter not overriding internally specified JsonConverter

Src/Newtonsoft.Json.Tests/Converters/DataTableConverterTests.cs

@@ -102,6 +102,40 @@ namespace Newtonsoft.Json.Tests.Converters
   }
 ]", json);
     }
+
+    public class TestDataTableConverter : JsonConverter
+    {
+      public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+      {
+        DataTable d = (DataTable) value;
+        writer.WriteValue(d.TableName);
+      }
+
+      public override object ReadJson(JsonReader reader, Type objectType, JsonSerializer serializer)
+      {
+        //reader.Read();
+        DataTable d = new DataTable((string)reader.Value);
+
+        return d;
+      }
+
+      public override bool CanConvert(Type objectType)
+      {
+        return (objectType == typeof (DataTable));
+      }
+    }
+
+    [Test]
+    public void PassedInJsonConverterOverridesInternalConverter()
+    {
+      DataTable t1 = new DataTable("Custom");
+
+      string json = JsonConvert.SerializeObject(t1, Formatting.Indented, new TestDataTableConverter());
+      Assert.AreEqual(@"""Custom""", json);
+
+      DataTable t2 = JsonConvert.DeserializeObject<DataTable>(json, new TestDataTableConverter());
+      Assert.AreEqual(t1.TableName, t2.TableName);
+    }
   }
 }
 #endif

Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs

@@ -181,14 +181,7 @@ namespace Newtonsoft.Json.Serialization
     /// <returns></returns>
     protected virtual JsonConverter ResolveContractConverter(Type objectType)
     {
-      // check for an attribute first
-      JsonConverter converter = JsonTypeReflector.GetJsonConverter(objectType, objectType);
-      if (converter != null)
-        return converter;
-
-      // then see whether object is compadible with any of the built in converters
-      JsonSerializer.HasMatchingConverter(BuiltInConverters, objectType, out converter);
-      return converter;
+      return JsonTypeReflector.GetJsonConverter(objectType, objectType);
     }
 
     private void InitializeContract(JsonContract contract)
@@ -210,6 +203,11 @@ namespace Newtonsoft.Json.Serialization
 
       contract.Converter = ResolveContractConverter(contract.UnderlyingType);
 
+      // then see whether object is compadible with any of the built in converters
+      JsonConverter internalConverter;
+      if (JsonSerializer.HasMatchingConverter(BuiltInConverters, contract.UnderlyingType, out internalConverter))
+        contract.InternalConverter = internalConverter;
+
       if (ReflectionUtils.HasDefaultConstructor(contract.CreatedType, true)
         || contract.CreatedType.IsValueType)
       {

Src/Newtonsoft.Json/Serialization/JsonContract.cs

@@ -59,6 +59,10 @@ namespace Newtonsoft.Json.Serialization
     /// <value>The converter.</value>
     public JsonConverter Converter { get; set; }
 
+    // internally specified JsonConverter's to override default behavour
+    // checked for after passed in converters and attribute specified converters
+    internal JsonConverter InternalConverter { get; set; }
+
 #if !PocketPC
     /// <summary>
     /// Gets or sets the method called immediately after deserialization of the object.

Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs

@@ -168,15 +168,22 @@ namespace Newtonsoft.Json.Serialization
     {
       JsonConverter converter;
 
+      // member attribute converter
       if (memberConverter != null)
         return memberConverter.ReadJson(reader, objectType, GetInternalSerializer());
 
+      // class attribute converter
       if (contract != null && contract.Converter != null)
         return contract.Converter.ReadJson(reader, objectType, GetInternalSerializer());
 
+      // passed in converters
       if (objectType != null && Serializer.HasMatchingConverter(objectType, out converter))
         return converter.ReadJson(reader, objectType, GetInternalSerializer());
 
+      // internally specified converter
+      if (contract != null && contract.InternalConverter != null)
+        return contract.InternalConverter.ReadJson(reader, objectType, GetInternalSerializer());
+
       if (contract is JsonLinqContract)
         return CreateJToken(reader, contract);
 

Src/Newtonsoft.Json/Serialization/JsonSerializerInternalWriter.cs

@@ -92,7 +92,8 @@ namespace Newtonsoft.Json.Serialization
 
       if (converter != null
           || ((converter = contract.Converter) != null)
-          || Serializer.HasMatchingConverter(contract.UnderlyingType, out converter))
+          || Serializer.HasMatchingConverter(contract.UnderlyingType, out converter)
+          || ((converter = contract.InternalConverter) != null))
       {
         SerializeConvertable(writer, converter, value, contract);
       }