XML Deserialization of nullable types with attributes

[PaulCampbell]

Hi there,

When trying to deserialize a nullable type, if the element has any attributes, the value is set to "", which is problematic.

here's a test:

[Fact]
public void Can_Deserialize_Empty_Elements_With_Attributes_to_Nullable_Values()
{
    var doc = CreateXmlWithAttributesAndNullValues();

    var xml = new XmlDeserializer();
    var output = xml.Deserialize<NullableValues>(new RestResponse { Content = doc });

    Assert.Null(output.Id);
    Assert.Null(output.StartDate);
    Assert.Null(output.UniqueId);
}

private static string CreateXmlWithAttributesAndNullValuesAndPopulatedValues()
{
    var doc = new XDocument();
    var root = new XElement("NullableValues");

    var idElement = new XElement("Id", null);
    idElement.SetAttributeValue("SomeAttribute", "SomeAttribute_Value");
    root.Add(idElement,
             new XElement("StartDate", null),
             new XElement("UniqueId", new Guid(GuidString))
        );

    doc.Add(root);

    return doc.ToString();
}

I have attached a pull request, with a further test and a fix.

Please give me a shout if you would like me to change anything, or if there's any problem

Thanks guys!