1 files changed, 57 insertions, 20 deletions
diff --git a/src/ProtocolBuffers.Serialization/XmlFormatWriter.cs b/src/ProtocolBuffers.Serialization/XmlFormatWriter.cs
index fd36c1de..4bd27562 100644
--- a/src/ProtocolBuffers.Serialization/XmlFormatWriter.cs
+++ b/src/ProtocolBuffers.Serialization/XmlFormatWriter.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.IO;
 using System.Text;
@@ -14,10 +14,14 @@ namespace Google.ProtocolBuffers.Serialization
     /// </summary>
     public class XmlFormatWriter : AbstractTextWriter
     {
+        private static readonly Encoding DefaultEncoding = new UTF8Encoding(false);
         public const string DefaultRootElementName = "root";
-        private const int NestedArrayFlag = 0x0001;
+
         private readonly XmlWriter _output;
+        // The default element name used for WriteMessageStart
         private string _rootElementName;
+        // Used to assert matching WriteMessageStart/WriteMessageEnd calls
+        private int _messageOpenCount;
 
         private static XmlWriterSettings DefaultSettings(Encoding encoding)
         {
@@ -43,7 +47,7 @@ namespace Google.ProtocolBuffers.Serialization
         /// </summary>
         public static XmlFormatWriter CreateInstance(Stream output)
         {
-            return new XmlFormatWriter(XmlWriter.Create(output, DefaultSettings(Encoding.UTF8)));
+            return new XmlFormatWriter(XmlWriter.Create(output, DefaultSettings(DefaultEncoding)));
         }
 
         /// <summary>
@@ -65,21 +69,11 @@ namespace Google.ProtocolBuffers.Serialization
         protected XmlFormatWriter(XmlWriter output)
         {
             _output = output;
+            _messageOpenCount = 0;
             _rootElementName = DefaultRootElementName;
         }
 
         /// <summary>
-        /// Closes the underlying XmlTextWriter
-        /// </summary>
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                _output.Close();
-            }
-        }
-
-        /// <summary>
         /// Gets or sets the default element name to use when using the Merge&lt;TBuilder>()
         /// </summary>
         public string RootElementName
@@ -112,17 +106,30 @@ namespace Google.ProtocolBuffers.Serialization
         }
 
         /// <summary>
-        /// Writes a message as an element using the name defined in <see cref="RootElementName"/>
+        /// Completes any pending write operations
         /// </summary>
-        public override void WriteMessage(IMessageLite message)
+        public override void Flush()
         {
-            WriteMessage(_rootElementName, message);
+            _output.Flush();
+            base.Flush();
         }
 
         /// <summary>
-        /// Writes a message as an element with the given name
+        /// Used to write the root-message preamble, in xml this is open element for RootElementName,
+        /// by default "&lt;root&gt;". After this call you can call IMessageLite.MergeTo(...) and 
+        /// complete the message with a call to WriteMessageEnd().
         /// </summary>
-        public void WriteMessage(string elementName, IMessageLite message)
+        public override void WriteMessageStart()
+        {
+            WriteMessageStart(_rootElementName);
+        }
+
+        /// <summary>
+        /// Used to write the root-message preamble, in xml this is open element for elementName. 
+        /// After this call you can call IMessageLite.MergeTo(...) and  complete the message with 
+        /// a call to WriteMessageEnd().
+        /// </summary>
+        public void WriteMessageStart(string elementName)
         {
             if (TestOption(XmlWriterOptions.OutputJsonTypes))
             {
@@ -133,10 +140,40 @@ namespace Google.ProtocolBuffers.Serialization
             {
                 _output.WriteStartElement(elementName);
             }
+            _messageOpenCount++;
+        }
+
+        /// <summary>
+        /// Used to complete a root-message previously started with a call to WriteMessageStart()
+        /// </summary>
+        public override void WriteMessageEnd()
+        {
+            if (_messageOpenCount <= 0)
+            {
+                throw new InvalidOperationException();
+            }
 
-            message.WriteTo(this);
             _output.WriteEndElement();
             _output.Flush();
+            _messageOpenCount--;
+        }
+
+        /// <summary>
+        /// Writes a message as an element using the name defined in <see cref="RootElementName"/>
+        /// </summary>
+        public override void WriteMessage(IMessageLite message)
+        {
+            WriteMessage(_rootElementName, message);
+        }
+
+        /// <summary>
+        /// Writes a message as an element with the given name
+        /// </summary>
+        public void WriteMessage(string elementName, IMessageLite message)
+        {
+            WriteMessageStart(elementName);
+            message.WriteTo(this);
+            WriteMessageEnd();
         }
 
         /// <summary>