1 files changed, 15 insertions, 7 deletions
diff --git a/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs b/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs
index 6ecc41e..11d553b 100644
--- a/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs
+++ b/src/DotNetOAuth/Messaging/DictionaryXmlReader.cs
@@ -10,6 +10,8 @@ namespace DotNetOAuth.Messaging {
 	using System.Diagnostics;
 	using System.IO;
 	using System.Linq;
+	using System.Reflection;
+	using System.Runtime.Serialization;
 	using System.Xml;
 	using System.Xml.Linq;
 
@@ -21,32 +23,38 @@ namespace DotNetOAuth.Messaging {
 		/// Creates an XmlReader that reads data out of a dictionary instead of XML.
 		/// </summary>
 		/// <param name="rootElement">The name of the root XML element.</param>
+		/// <param name="fieldSorter">The field sorter so that the XmlReader generates xml elements in the order required by the <see cref="DataContractSerializer"/>.</param>
 		/// <param name="fields">The dictionary to read data from.</param>
 		/// <returns>The XmlReader that will read the data out of the given dictionary.</returns>
-		internal static XmlReader Create(XName rootElement, IDictionary<string, string> fields) {
+		internal static XmlReader Create(XName rootElement, IComparer<string> fieldSorter, IDictionary<string, string> fields) {
 			if (rootElement == null) {
 				throw new ArgumentNullException("rootElement");
 			}
+			if (fieldSorter == null) {
+				throw new ArgumentNullException("fieldSorter");
+			}
 			if (fields == null) {
 				throw new ArgumentNullException("fields");
 			}
 
-			return CreateRoundtripReader(rootElement, fields);
+			return CreateRoundtripReader(rootElement, fieldSorter, fields);
 		}
 
 		/// <summary>
 		/// Creates an <see cref="XmlReader"/> that will read values out of a dictionary.
 		/// </summary>
 		/// <param name="rootElement">The surrounding root XML element to generate.</param>
+		/// <param name="fieldSorter">The field sorter so that the XmlReader generates xml elements in the order required by the <see cref="DataContractSerializer"/>.</param>
 		/// <param name="fields">The dictionary to list values from.</param>
 		/// <returns>The generated <see cref="XmlReader"/>.</returns>
-		private static XmlReader CreateRoundtripReader(XName rootElement, IDictionary<string, string> fields) {
+		private static XmlReader CreateRoundtripReader(XName rootElement, IComparer<string> fieldSorter, IDictionary<string, string> fields) {
 			Debug.Assert(rootElement != null, "rootElement == null");
+			Debug.Assert(fieldSorter != null, "fieldSorter == null");
 			Debug.Assert(fields != null, "fields == null");
 
 			MemoryStream stream = new MemoryStream();
 			XmlWriter writer = XmlWriter.Create(stream);
-			SerializeDictionaryToXml(writer, rootElement, fields);
+			SerializeDictionaryToXml(writer, rootElement, fieldSorter, fields);
 			writer.Flush();
 			stream.Seek(0, SeekOrigin.Begin);
 
@@ -63,16 +71,16 @@ namespace DotNetOAuth.Messaging {
 		/// </summary>
 		/// <param name="writer">The <see cref="XmlWriter"/> to write out the XML to.</param>
 		/// <param name="rootElement">The name of the root element to use to surround the dictionary values.</param>
+		/// <param name="fieldSorter">The field sorter so that the XmlReader generates xml elements in the order required by the <see cref="DataContractSerializer"/>.</param>
 		/// <param name="fields">The dictionary with values to serialize.</param>
-		private static void SerializeDictionaryToXml(XmlWriter writer, XName rootElement, IDictionary<string, string> fields) {
+		private static void SerializeDictionaryToXml(XmlWriter writer, XName rootElement, IComparer<string> fieldSorter, IDictionary<string, string> fields) {
 			Debug.Assert(writer != null, "writer == null");
 			Debug.Assert(rootElement != null, "rootElement == null");
 			Debug.Assert(fields != null, "fields == null");
 
 			writer.WriteStartElement(rootElement.LocalName, rootElement.NamespaceName);
 
-			// The elements must be serialized in alphabetical order so the DataContractSerializer will see them.
-			foreach (var pair in fields.OrderBy(pair => pair.Key, StringComparer.Ordinal)) {
+			foreach (var pair in fields.OrderBy(pair => pair.Key, fieldSorter)) {
 				writer.WriteStartElement(pair.Key, rootElement.NamespaceName);
 				writer.WriteValue(pair.Value);
 				writer.WriteEndElement();