diff --git a/csharp/ProtocolBuffers.Test/CodedInputStreamTest.cs b/csharp/ProtocolBuffers.Test/CodedInputStreamTest.cs
index c2b2a8321..3be8041cd 100644
--- a/csharp/ProtocolBuffers.Test/CodedInputStreamTest.cs
+++ b/csharp/ProtocolBuffers.Test/CodedInputStreamTest.cs
@@ -15,6 +15,7 @@
 // limitations under the License.
 using System;
 using System.IO;
+using Google.ProtocolBuffers.TestProtos;
 using NUnit.Framework;
 
 namespace Google.ProtocolBuffers {
@@ -183,23 +184,22 @@ namespace Google.ProtocolBuffers {
       Assert.AreEqual(unchecked((long)0x8000000000000000L), CodedInputStream.DecodeZigZag64(0xFFFFFFFFFFFFFFFFL));
     }
 
-    /* TODO(jonskeet): Reinstate this when protoc is ready
-    public void testReadWholeMessage() throws Exception {
-      TestAllTypes message = TestUtil.getAllSet();
+    [Test]
+    public void ReadWholeMessage() {
+      TestAllTypes message = TestUtil.GetAllSet();
 
-      byte[] rawBytes = message.toByteArray();
-      assertEquals(rawBytes.length, message.getSerializedSize());
+      byte[] rawBytes = message.ToByteArray();
+      Assert.AreEqual(rawBytes.Length, message.SerializedSize);
 
-      TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
-      TestUtil.assertAllFieldsSet(message2);
+      TestAllTypes message2 = TestAllTypes.ParseFrom(rawBytes);
+      TestUtil.AssertAllFieldsSet(message2);
 
       // Try different block sizes.
       for (int blockSize = 1; blockSize < 256; blockSize *= 2) {
-        message2 = TestAllTypes.parseFrom(
-          new SmallBlockInputStream(rawBytes, blockSize));
-        TestUtil.assertAllFieldsSet(message2);
+        message2 = TestAllTypes.ParseFrom(new SmallBlockInputStream(rawBytes, blockSize));
+        TestUtil.AssertAllFieldsSet(message2);
       }
-    }*/
+    }
 
     /* TODO(jonskeet): Reinstate this when protoc is ready
     public void testSkipWholeMessage() throws Exception {
diff --git a/csharp/ProtocolBuffers.Test/TestUtil.cs b/csharp/ProtocolBuffers.Test/TestUtil.cs
index 40ad878da..190e8f759 100644
--- a/csharp/ProtocolBuffers.Test/TestUtil.cs
+++ b/csharp/ProtocolBuffers.Test/TestUtil.cs
@@ -2,6 +2,8 @@
 using System.Collections.Generic;
 using System.Text;
 using System.IO;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
 
 namespace Google.ProtocolBuffers {
   internal static class TestUtil {
@@ -28,5 +30,337 @@ namespace Google.ProtocolBuffers {
         throw new Exception("Unable to find directory containing test files");
       }
     }
+
+    /// <summary>
+    /// Helper to convert a String to ByteString.
+    /// </summary>
+    private static ByteString ToBytes(String str) {
+      return ByteString.CopyFrom(Encoding.UTF8.GetBytes(str));
+    }
+
+    internal static TestAllTypes GetAllSet() {
+      TestAllTypes.Builder builder = TestAllTypes.CreateBuilder();
+      SetAllFields(builder);
+      return builder.Build();
+    }
+
+    /// <summary>
+    /// Sets every field of the specified message to the values expected by
+    /// AssertAllFieldsSet.
+    /// </summary>
+    internal static void SetAllFields(TestAllTypes.Builder message) {
+      message.SetOptionalInt32(101);
+      message.SetOptionalInt64(102);
+      message.SetOptionalUint32(103);
+      message.SetOptionalUint64(104);
+      message.SetOptionalSint32(105);
+      message.SetOptionalSint64(106);
+      message.SetOptionalFixed32(107);
+      message.SetOptionalFixed64(108);
+      message.SetOptionalSfixed32(109);
+      message.SetOptionalSfixed64(110);
+      message.SetOptionalFloat(111);
+      message.SetOptionalDouble(112);
+      message.SetOptionalBool(true);
+      message.SetOptionalString("115");
+      message.SetOptionalBytes(ToBytes("116"));
+      
+      message.SetOptionalGroup(TestAllTypes.Types.OptionalGroup.CreateBuilder().SetA(117).Build());
+      message.SetOptionalNestedMessage(TestAllTypes.Types.NestedMessage.CreateBuilder().SetBb(118).Build());
+      message.SetOptionalForeignMessage(ForeignMessage.CreateBuilder().SetC(119).Build());
+      message.SetOptionalImportMessage(ImportMessage.CreateBuilder().SetD(120).Build());
+
+      message.SetOptionalNestedEnum(TestAllTypes.Types.NestedEnum.BAZ);
+      message.SetOptionalForeignEnum(ForeignEnum.FOREIGN_BAZ);
+      message.SetOptionalImportEnum(ImportEnum.IMPORT_BAZ);
+
+      message.SetOptionalStringPiece("124");
+      message.SetOptionalCord("125");
+
+      // -----------------------------------------------------------------
+
+      message.AddRepeatedInt32(201);
+      message.AddRepeatedInt64(202);
+      message.AddRepeatedUint32(203);
+      message.AddRepeatedUint64(204);
+      message.AddRepeatedSint32(205);
+      message.AddRepeatedSint64(206);
+      message.AddRepeatedFixed32(207);
+      message.AddRepeatedFixed64(208);
+      message.AddRepeatedSfixed32(209);
+      message.AddRepeatedSfixed64(210);
+      message.AddRepeatedFloat(211);
+      message.AddRepeatedDouble(212);
+      message.AddRepeatedBool(true);
+      message.AddRepeatedString("215");
+      message.AddRepeatedBytes(ToBytes("216"));
+
+      message.AddRepeatedGroup(TestAllTypes.Types.RepeatedGroup.CreateBuilder().SetA(217).Build());
+      message.AddRepeatedNestedMessage(TestAllTypes.Types.NestedMessage.CreateBuilder().SetBb(218).Build());
+      message.AddRepeatedForeignMessage(ForeignMessage.CreateBuilder().SetC(219).Build());
+      message.AddRepeatedImportMessage(ImportMessage.CreateBuilder().SetD(220).Build());
+
+      message.AddRepeatedNestedEnum(TestAllTypes.Types.NestedEnum.BAR);
+      message.AddRepeatedForeignEnum(ForeignEnum.FOREIGN_BAR);
+      message.AddRepeatedImportEnum(ImportEnum.IMPORT_BAR);
+
+      message.AddRepeatedStringPiece("224");
+      message.AddRepeatedCord("225");
+
+      // Add a second one of each field.
+      message.AddRepeatedInt32(301);
+      message.AddRepeatedInt64(302);
+      message.AddRepeatedUint32(303);
+      message.AddRepeatedUint64(304);
+      message.AddRepeatedSint32(305);
+      message.AddRepeatedSint64(306);
+      message.AddRepeatedFixed32(307);
+      message.AddRepeatedFixed64(308);
+      message.AddRepeatedSfixed32(309);
+      message.AddRepeatedSfixed64(310);
+      message.AddRepeatedFloat(311);
+      message.AddRepeatedDouble(312);
+      message.AddRepeatedBool(false);
+      message.AddRepeatedString("315");
+      message.AddRepeatedBytes(ToBytes("316"));
+
+      message.AddRepeatedGroup(TestAllTypes.Types.RepeatedGroup.CreateBuilder().SetA(317).Build());
+      message.AddRepeatedNestedMessage(TestAllTypes.Types.NestedMessage.CreateBuilder().SetBb(318).Build());
+      message.AddRepeatedForeignMessage(ForeignMessage.CreateBuilder().SetC(319).Build());
+      message.AddRepeatedImportMessage(ImportMessage.CreateBuilder().SetD(320).Build());
+
+      message.AddRepeatedNestedEnum(TestAllTypes.Types.NestedEnum.BAZ);
+      message.AddRepeatedForeignEnum(ForeignEnum.FOREIGN_BAZ);
+      message.AddRepeatedImportEnum(ImportEnum.IMPORT_BAZ);
+
+      message.AddRepeatedStringPiece("324");
+      message.AddRepeatedCord("325");
+
+      // -----------------------------------------------------------------
+
+      message.SetDefaultInt32(401);
+      message.SetDefaultInt64(402);
+      message.SetDefaultUint32(403);
+      message.SetDefaultUint64(404);
+      message.SetDefaultSint32(405);
+      message.SetDefaultSint64(406);
+      message.SetDefaultFixed32(407);
+      message.SetDefaultFixed64(408);
+      message.SetDefaultSfixed32(409);
+      message.SetDefaultSfixed64(410);
+      message.SetDefaultFloat(411);
+      message.SetDefaultDouble(412);
+      message.SetDefaultBool(false);
+      message.SetDefaultString("415");
+      message.SetDefaultBytes(ToBytes("416"));
+      
+      message.SetDefaultNestedEnum(TestAllTypes.Types.NestedEnum.FOO);
+      message.SetDefaultForeignEnum(ForeignEnum.FOREIGN_FOO);
+      message.SetDefaultImportEnum(ImportEnum.IMPORT_FOO);
+
+      message.SetDefaultStringPiece("424");
+      message.SetDefaultCord("425");
+    }
+
+    /// <summary>
+    /// Asserts that all fields of the specified message are set to the values
+    /// assigned by SetAllFields.
+    /// </summary>
+    internal static void AssertAllFieldsSet(TestAllTypes message) {
+      Assert.IsTrue(message.HasOptionalInt32);
+      Assert.IsTrue(message.HasOptionalInt64);
+      Assert.IsTrue(message.HasOptionalUint32);
+      Assert.IsTrue(message.HasOptionalUint64);
+      Assert.IsTrue(message.HasOptionalSint32);
+      Assert.IsTrue(message.HasOptionalSint64);
+      Assert.IsTrue(message.HasOptionalFixed32);
+      Assert.IsTrue(message.HasOptionalFixed64);
+      Assert.IsTrue(message.HasOptionalSfixed32);
+      Assert.IsTrue(message.HasOptionalSfixed64);
+      Assert.IsTrue(message.HasOptionalFloat);
+      Assert.IsTrue(message.HasOptionalDouble);
+      Assert.IsTrue(message.HasOptionalBool);
+      Assert.IsTrue(message.HasOptionalString);
+      Assert.IsTrue(message.HasOptionalBytes);
+
+      Assert.IsTrue(message.HasOptionalGroup);
+      Assert.IsTrue(message.HasOptionalNestedMessage);
+      Assert.IsTrue(message.HasOptionalForeignMessage);
+      Assert.IsTrue(message.HasOptionalImportMessage);
+
+      Assert.IsTrue(message.OptionalGroup.HasA);
+      Assert.IsTrue(message.OptionalNestedMessage.HasBb);
+      Assert.IsTrue(message.OptionalForeignMessage.HasC);
+      Assert.IsTrue(message.OptionalImportMessage.HasD);
+
+      Assert.IsTrue(message.HasOptionalNestedEnum);
+      Assert.IsTrue(message.HasOptionalForeignEnum);
+      Assert.IsTrue(message.HasOptionalImportEnum);
+
+      Assert.IsTrue(message.HasOptionalStringPiece);
+      Assert.IsTrue(message.HasOptionalCord);
+
+      Assert.AreEqual(101, message.OptionalInt32);
+      Assert.AreEqual(102, message.OptionalInt64);
+      Assert.AreEqual(103, message.OptionalUint32);
+      Assert.AreEqual(104, message.OptionalUint64);
+      Assert.AreEqual(105, message.OptionalSint32);
+      Assert.AreEqual(106, message.OptionalSint64);
+      Assert.AreEqual(107, message.OptionalFixed32);
+      Assert.AreEqual(108, message.OptionalFixed64);
+      Assert.AreEqual(109, message.OptionalSfixed32);
+      Assert.AreEqual(110, message.OptionalSfixed64);
+      Assert.AreEqual(111, message.OptionalFloat);
+      Assert.AreEqual(112, message.OptionalDouble);
+      Assert.AreEqual(true, message.OptionalBool);
+      Assert.AreEqual("115", message.OptionalString);
+      Assert.AreEqual(ToBytes("116"), message.OptionalBytes);
+
+      Assert.AreEqual(117, message.OptionalGroup.A);
+      Assert.AreEqual(118, message.OptionalNestedMessage.Bb);
+      Assert.AreEqual(119, message.OptionalForeignMessage.C);
+      Assert.AreEqual(120, message.OptionalImportMessage.D);
+
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.BAZ, message.OptionalNestedEnum);
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, message.OptionalForeignEnum);
+      Assert.AreEqual(ImportEnum.IMPORT_BAZ, message.OptionalImportEnum);
+
+      Assert.AreEqual("124", message.OptionalStringPiece);
+      Assert.AreEqual("125", message.OptionalCord);
+
+      // -----------------------------------------------------------------
+
+      Assert.AreEqual(2, message.RepeatedInt32Count);
+      Assert.AreEqual(2, message.RepeatedInt64Count);
+      Assert.AreEqual(2, message.RepeatedUint32Count);
+      Assert.AreEqual(2, message.RepeatedUint64Count);
+      Assert.AreEqual(2, message.RepeatedSint32Count);
+      Assert.AreEqual(2, message.RepeatedSint64Count);
+      Assert.AreEqual(2, message.RepeatedFixed32Count);
+      Assert.AreEqual(2, message.RepeatedFixed64Count);
+      Assert.AreEqual(2, message.RepeatedSfixed32Count);
+      Assert.AreEqual(2, message.RepeatedSfixed64Count);
+      Assert.AreEqual(2, message.RepeatedFloatCount);
+      Assert.AreEqual(2, message.RepeatedDoubleCount);
+      Assert.AreEqual(2, message.RepeatedBoolCount);
+      Assert.AreEqual(2, message.RepeatedStringCount);
+      Assert.AreEqual(2, message.RepeatedBytesCount);
+
+      Assert.AreEqual(2, message.RepeatedGroupCount         );
+      Assert.AreEqual(2, message.RepeatedNestedMessageCount );
+      Assert.AreEqual(2, message.RepeatedForeignMessageCount);
+      Assert.AreEqual(2, message.RepeatedImportMessageCount );
+      Assert.AreEqual(2, message.RepeatedNestedEnumCount    );
+      Assert.AreEqual(2, message.RepeatedForeignEnumCount   );
+      Assert.AreEqual(2, message.RepeatedImportEnumCount    );
+
+      Assert.AreEqual(2, message.RepeatedStringPieceCount);
+      Assert.AreEqual(2, message.RepeatedCordCount);
+
+      Assert.AreEqual(201, message.GetRepeatedInt32(0));
+      Assert.AreEqual(202, message.GetRepeatedInt64(0));
+      Assert.AreEqual(203, message.GetRepeatedUint32(0));
+      Assert.AreEqual(204, message.GetRepeatedUint64(0));
+      Assert.AreEqual(205, message.GetRepeatedSint32(0));
+      Assert.AreEqual(206, message.GetRepeatedSint64(0));
+      Assert.AreEqual(207, message.GetRepeatedFixed32(0));
+      Assert.AreEqual(208, message.GetRepeatedFixed64(0));
+      Assert.AreEqual(209, message.GetRepeatedSfixed32(0));
+      Assert.AreEqual(210, message.GetRepeatedSfixed64(0));
+      Assert.AreEqual(211, message.GetRepeatedFloat(0));
+      Assert.AreEqual(212, message.GetRepeatedDouble(0));
+      Assert.AreEqual(true , message.GetRepeatedBool(0));
+      Assert.AreEqual("215", message.GetRepeatedString(0));
+      Assert.AreEqual(ToBytes("216"), message.GetRepeatedBytes(0));
+
+      Assert.AreEqual(217, message.GetRepeatedGroup(0).A);
+      Assert.AreEqual(218, message.GetRepeatedNestedMessage (0).Bb);
+      Assert.AreEqual(219, message.GetRepeatedForeignMessage(0).C);
+      Assert.AreEqual(220, message.GetRepeatedImportMessage (0).D);
+
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.BAR, message.GetRepeatedNestedEnum (0));
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAR, message.GetRepeatedForeignEnum(0));
+      Assert.AreEqual(ImportEnum.IMPORT_BAR, message.GetRepeatedImportEnum(0));
+
+      Assert.AreEqual("224", message.GetRepeatedStringPiece(0));
+      Assert.AreEqual("225", message.GetRepeatedCord(0));
+
+      Assert.AreEqual(301, message.GetRepeatedInt32   (1));
+      Assert.AreEqual(302, message.GetRepeatedInt64   (1));
+      Assert.AreEqual(303, message.GetRepeatedUint32  (1));
+      Assert.AreEqual(304, message.GetRepeatedUint64  (1));
+      Assert.AreEqual(305, message.GetRepeatedSint32  (1));
+      Assert.AreEqual(306, message.GetRepeatedSint64  (1));
+      Assert.AreEqual(307, message.GetRepeatedFixed32 (1));
+      Assert.AreEqual(308, message.GetRepeatedFixed64 (1));
+      Assert.AreEqual(309, message.GetRepeatedSfixed32(1));
+      Assert.AreEqual(310, message.GetRepeatedSfixed64(1));
+      Assert.AreEqual(311, message.GetRepeatedFloat   (1), 0.0);
+      Assert.AreEqual(312, message.GetRepeatedDouble  (1), 0.0);
+      Assert.AreEqual(false, message.GetRepeatedBool    (1));
+      Assert.AreEqual("315", message.GetRepeatedString  (1));
+      Assert.AreEqual(ToBytes("316"), message.GetRepeatedBytes(1));
+
+      Assert.AreEqual(317, message.GetRepeatedGroup         (1).A);
+      Assert.AreEqual(318, message.GetRepeatedNestedMessage (1).Bb);
+      Assert.AreEqual(319, message.GetRepeatedForeignMessage(1).C);
+      Assert.AreEqual(320, message.GetRepeatedImportMessage (1).D);
+
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.BAZ, message.GetRepeatedNestedEnum (1));
+      Assert.AreEqual(ForeignEnum.FOREIGN_BAZ, message.GetRepeatedForeignEnum(1));
+      Assert.AreEqual(ImportEnum.IMPORT_BAZ, message.GetRepeatedImportEnum(1));
+
+      Assert.AreEqual("324", message.GetRepeatedStringPiece(1));
+      Assert.AreEqual("325", message.GetRepeatedCord(1));
+
+      // -----------------------------------------------------------------
+
+      Assert.IsTrue(message.HasDefaultInt32   );
+      Assert.IsTrue(message.HasDefaultInt64   );
+      Assert.IsTrue(message.HasDefaultUint32  );
+      Assert.IsTrue(message.HasDefaultUint64  );
+      Assert.IsTrue(message.HasDefaultSint32  );
+      Assert.IsTrue(message.HasDefaultSint64  );
+      Assert.IsTrue(message.HasDefaultFixed32 );
+      Assert.IsTrue(message.HasDefaultFixed64 );
+      Assert.IsTrue(message.HasDefaultSfixed32);
+      Assert.IsTrue(message.HasDefaultSfixed64);
+      Assert.IsTrue(message.HasDefaultFloat   );
+      Assert.IsTrue(message.HasDefaultDouble  );
+      Assert.IsTrue(message.HasDefaultBool    );
+      Assert.IsTrue(message.HasDefaultString  );
+      Assert.IsTrue(message.HasDefaultBytes   );
+
+      Assert.IsTrue(message.HasDefaultNestedEnum );
+      Assert.IsTrue(message.HasDefaultForeignEnum);
+      Assert.IsTrue(message.HasDefaultImportEnum );
+
+      Assert.IsTrue(message.HasDefaultStringPiece);
+      Assert.IsTrue(message.HasDefaultCord);
+
+      Assert.AreEqual(401, message.DefaultInt32);
+      Assert.AreEqual(402, message.DefaultInt64);
+      Assert.AreEqual(403, message.DefaultUint32);
+      Assert.AreEqual(404, message.DefaultUint64);
+      Assert.AreEqual(405, message.DefaultSint32);
+      Assert.AreEqual(406, message.DefaultSint64);
+      Assert.AreEqual(407, message.DefaultFixed32);
+      Assert.AreEqual(408, message.DefaultFixed64);
+      Assert.AreEqual(409, message.DefaultSfixed32);
+      Assert.AreEqual(410, message.DefaultSfixed64);
+      Assert.AreEqual(411, message.DefaultFloat);
+      Assert.AreEqual(412, message.DefaultDouble);
+      Assert.AreEqual(false, message.DefaultBool    );
+      Assert.AreEqual("415", message.DefaultString  );
+      Assert.AreEqual(ToBytes("416"), message.DefaultBytes);
+
+      Assert.AreEqual(TestAllTypes.Types.NestedEnum.FOO, message.DefaultNestedEnum);
+      Assert.AreEqual(ForeignEnum.FOREIGN_FOO, message.DefaultForeignEnum);
+      Assert.AreEqual(ImportEnum.IMPORT_FOO, message.DefaultImportEnum);
+
+      Assert.AreEqual("424", message.DefaultStringPiece);
+      Assert.AreEqual("425", message.DefaultCord);
+    }
+
   }
 }
diff --git a/csharp/ProtocolBuffers/AbstractBuilder.cs b/csharp/ProtocolBuffers/AbstractBuilder.cs
index 02626f918..256975e9e 100644
--- a/csharp/ProtocolBuffers/AbstractBuilder.cs
+++ b/csharp/ProtocolBuffers/AbstractBuilder.cs
@@ -104,16 +104,20 @@ namespace Google.ProtocolBuffers {
     }
 
     IBuilder IBuilder.MergeFrom(CodedInputStream input) {
-      return ((IBuilder)this).MergeFrom(input, ExtensionRegistry.Empty);
+      return MergeFromImpl(input, ExtensionRegistry.Empty);
     }
 
-    IBuilder IBuilder.MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
+    protected virtual IBuilder MergeFromImpl(CodedInputStream input, ExtensionRegistry extensionRegistry) {
       UnknownFieldSet.Builder unknownFields = UnknownFieldSet.CreateBuilder(UnknownFields);
       FieldSet.MergeFrom(input, unknownFields, extensionRegistry, this);
       UnknownFields = unknownFields.Build();
       return this;
     }
 
+    IBuilder IBuilder.MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
+      return MergeFromImpl(input, extensionRegistry);
+    }
+
     IBuilder IBuilder.MergeUnknownFields(UnknownFieldSet unknownFields) {
       UnknownFields = UnknownFieldSet.CreateBuilder(UnknownFields)
           .MergeFrom(unknownFields)
@@ -121,8 +125,6 @@ namespace Google.ProtocolBuffers {
       return this;
     }
 
-    public UnknownFieldSet UnknownFields { get; set; }
-
     IBuilder IBuilder.MergeFrom(ByteString data) {
       CodedInputStream input = data.CreateCodedInput();
       ((IBuilder)this).MergeFrom(input);
@@ -160,9 +162,11 @@ namespace Google.ProtocolBuffers {
 
     IBuilder IBuilder.MergeFrom(Stream input, ExtensionRegistry extensionRegistry) {
       CodedInputStream codedInput = CodedInputStream.CreateInstance(input);
-      ((IBuilder) this).MergeFrom(codedInput, extensionRegistry);
+      ((IBuilder)this).MergeFrom(codedInput, extensionRegistry);
       codedInput.CheckLastTagWas(0);
       return this;
     }
+
+    public abstract UnknownFieldSet UnknownFields { get; set; }
   }
 }
diff --git a/csharp/ProtocolBuffers/ByteString.cs b/csharp/ProtocolBuffers/ByteString.cs
index 7c644f9a8..8a7909e39 100644
--- a/csharp/ProtocolBuffers/ByteString.cs
+++ b/csharp/ProtocolBuffers/ByteString.cs
@@ -23,7 +23,7 @@ namespace Google.ProtocolBuffers {
   /// Immutable array of bytes.
   /// TODO(jonskeet): Implement the common collection interfaces?
   /// </summary>
-  public sealed class ByteString : IEnumerable<byte> {
+  public sealed class ByteString : IEnumerable<byte>, IEquatable<ByteString> {
 
     private static readonly ByteString empty = new ByteString(new byte[0]);
 
@@ -126,6 +126,34 @@ namespace Google.ProtocolBuffers {
 
     // TODO(jonskeet): CopyTo, Equals, GetHashCode if they turn out to be required
 
+    public override bool Equals(object obj) {
+      ByteString other = obj as ByteString;
+      if (obj == null) {
+        return false;
+      }
+      return Equals(other);
+    }
+
+    public override int GetHashCode() {
+      int ret = 23;
+      foreach (byte b in bytes) {
+        ret = (ret << 8) | b;
+      }
+      return ret;
+    }
+
+    public bool Equals(ByteString other) {
+      if (other.bytes.Length != bytes.Length) {
+        return false;
+      }
+      for (int i = 0; i < bytes.Length; i++) {
+        if (other.bytes[i] != bytes[i]) {
+          return false;
+        }
+      }
+      return true;
+    }
+
     /// <summary>
     /// Builder for ByteStrings which allows them to be created without extra
     /// copying being involved. This has to be a nested type in order to have access
diff --git a/csharp/ProtocolBuffers/CodedInputStream.cs b/csharp/ProtocolBuffers/CodedInputStream.cs
index 418f58097..7fab7d210 100644
--- a/csharp/ProtocolBuffers/CodedInputStream.cs
+++ b/csharp/ProtocolBuffers/CodedInputStream.cs
@@ -569,8 +569,8 @@ namespace Google.ProtocolBuffers {
       totalBytesRetired += bufferSize;
 
       bufferPos = 0;
-      bufferSize = (input == null) ? -1 : input.Read(buffer, 0, buffer.Length);
-      if (bufferSize == -1) {
+      bufferSize = (input == null) ? 0 : input.Read(buffer, 0, buffer.Length);
+      if (bufferSize == 0) {
         bufferSize = 0;
         if (mustSucceed) {
           throw InvalidProtocolBufferException.TruncatedMessage();
diff --git a/csharp/ProtocolBuffers/CodedOutputStream.cs b/csharp/ProtocolBuffers/CodedOutputStream.cs
index fff30d3f0..6314a7029 100644
--- a/csharp/ProtocolBuffers/CodedOutputStream.cs
+++ b/csharp/ProtocolBuffers/CodedOutputStream.cs
@@ -206,6 +206,7 @@ namespace Google.ProtocolBuffers {
 
     public void WriteBytes(int fieldNumber, ByteString value) {
       // TODO(jonskeet): Optimise this! (No need to copy the bytes twice.)
+      WriteTag(fieldNumber, WireFormat.WireType.LengthDelimited);
       byte[] bytes = value.ToByteArray();
       WriteRawVarint32((uint)bytes.Length);
       WriteRawBytes(bytes);
@@ -223,12 +224,12 @@ namespace Google.ProtocolBuffers {
 
     public void WriteSFixed32(int fieldNumber, int value) {
       WriteTag(fieldNumber, WireFormat.WireType.Fixed32);
-      WriteRawVarint32((uint)value);
+      WriteRawLittleEndian32((uint)value);
     }
 
     public void WriteSFixed64(int fieldNumber, long value) {
       WriteTag(fieldNumber, WireFormat.WireType.Fixed64);
-      WriteRawVarint64((ulong)value);
+      WriteRawLittleEndian64((ulong)value);
     }
 
     public void WriteSInt32(int fieldNumber, int value) {
diff --git a/csharp/ProtocolBuffers/Descriptors/FieldDescriptor.cs b/csharp/ProtocolBuffers/Descriptors/FieldDescriptor.cs
index 38e6adfa2..f2f99a389 100644
--- a/csharp/ProtocolBuffers/Descriptors/FieldDescriptor.cs
+++ b/csharp/ProtocolBuffers/Descriptors/FieldDescriptor.cs
@@ -22,7 +22,7 @@ namespace Google.ProtocolBuffers.Descriptors {
       
       if (proto.HasType) {
         fieldType = GetFieldTypeFromProtoType(proto.Type);
-        //type = proto.Type;
+        mappedType = FieldTypeToMappedTypeMap[fieldType];
       }
       
       if (FieldNumber <= 0) {
@@ -244,8 +244,7 @@ namespace Google.ProtocolBuffers.Descriptors {
     /// Immutable mapping from field type to mapped type. Built using the attributes on
     /// FieldType values.
     /// </summary>
-    public static readonly IDictionary<FieldType, MappedType> FieldTypeToWireFormatMap = MapFieldTypes();
-
+    public static readonly IDictionary<FieldType, MappedType> FieldTypeToMappedTypeMap = MapFieldTypes();
 
     private static IDictionary<FieldType, MappedType> MapFieldTypes() {
       var map = new Dictionary<FieldType, MappedType>();
diff --git a/csharp/ProtocolBuffers/Descriptors/MessageDescriptor.cs b/csharp/ProtocolBuffers/Descriptors/MessageDescriptor.cs
index 548f226b8..b733fb935 100644
--- a/csharp/ProtocolBuffers/Descriptors/MessageDescriptor.cs
+++ b/csharp/ProtocolBuffers/Descriptors/MessageDescriptor.cs
@@ -19,16 +19,16 @@ namespace Google.ProtocolBuffers.Descriptors {
       containingType = parent;
 
       nestedTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.NestedTypeList,
-          (type, index) => new MessageDescriptor(type, file, null, index));
+          (type, index) => new MessageDescriptor(type, file, this, index));
 
       enumTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.EnumTypeList,
-          (type, index) => new EnumDescriptor(type, file, null, index));
+          (type, index) => new EnumDescriptor(type, file, this, index));
 
       fields = DescriptorUtil.ConvertAndMakeReadOnly(proto.FieldList,
-          (field, index) => new FieldDescriptor(field, file, null, index, false));
+          (field, index) => new FieldDescriptor(field, file, this, index, false));
 
       extensions = DescriptorUtil.ConvertAndMakeReadOnly(proto.ExtensionList,
-          (field, index) => new FieldDescriptor(field, file, null, index, true));
+          (field, index) => new FieldDescriptor(field, file, this, index, true));
 
       file.DescriptorPool.AddSymbol(this);
     }
diff --git a/csharp/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs b/csharp/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs
index 6f40938ee..18da75c4b 100644
--- a/csharp/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs
+++ b/csharp/ProtocolBuffers/FieldAccess/RepeatedMessageAccessor.cs
@@ -21,7 +21,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
 
     internal RepeatedMessageAccessor(string name, Type messageType, Type builderType)
         : base(name, messageType, builderType) {
-      createBuilderMethod = ClrType.GetMethod("CreateBuilder", BindingFlags.Public | BindingFlags.Static);
+      createBuilderMethod = ClrType.GetMethod("CreateBuilder", new Type[0]);
       if (createBuilderMethod == null) {
         throw new ArgumentException("No public static CreateBuilder method declared in " + ClrType.Name);
       }
diff --git a/csharp/ProtocolBuffers/FieldAccess/RepeatedPrimitiveAccessor.cs b/csharp/ProtocolBuffers/FieldAccess/RepeatedPrimitiveAccessor.cs
index 232a1e28d..11611b64d 100644
--- a/csharp/ProtocolBuffers/FieldAccess/RepeatedPrimitiveAccessor.cs
+++ b/csharp/ProtocolBuffers/FieldAccess/RepeatedPrimitiveAccessor.cs
@@ -11,7 +11,6 @@ namespace Google.ProtocolBuffers.FieldAccess {
 
     private readonly PropertyInfo messageProperty;
     private readonly PropertyInfo builderProperty;
-    private readonly PropertyInfo hasProperty;
     private readonly PropertyInfo countProperty;
     private readonly MethodInfo clearMethod;
     private readonly MethodInfo addMethod;
@@ -30,15 +29,13 @@ namespace Google.ProtocolBuffers.FieldAccess {
     internal RepeatedPrimitiveAccessor(string name, Type messageType, Type builderType) {      
       messageProperty = messageType.GetProperty(name + "List");
       builderProperty = builderType.GetProperty(name + "List");
-      hasProperty = messageType.GetProperty("Has" + name);
       countProperty = messageType.GetProperty(name + "Count");
       clearMethod = builderType.GetMethod("Clear" + name);
-      addMethod = builderType.GetMethod("Add" + name);
       getElementMethod = messageType.GetMethod("Get" + name, new Type[] { typeof(int) });
-      setElementMethod = builderType.GetMethod("Set" + name, new Type[] { typeof(int) });
+      addMethod = builderType.GetMethod("Add" + name, new Type[] { ClrType });
+      setElementMethod = builderType.GetMethod("Set" + name, new Type[] { typeof(int), ClrType });
       if (messageProperty == null 
           || builderProperty == null 
-          || hasProperty == null 
           || countProperty == null
           || clearMethod == null
           || addMethod == null
diff --git a/csharp/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs b/csharp/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs
index c9647b072..20e1ba133 100644
--- a/csharp/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs
+++ b/csharp/ProtocolBuffers/FieldAccess/SingleMessageAccessor.cs
@@ -19,7 +19,7 @@ namespace Google.ProtocolBuffers.FieldAccess {
     internal SingleMessageAccessor(string name, Type messageType, Type builderType) 
         : base(name, messageType, builderType) {
       
-      createBuilderMethod = ClrType.GetMethod("CreateBuilder", BindingFlags.Public | BindingFlags.Static);
+      createBuilderMethod = ClrType.GetMethod("CreateBuilder", new Type[0]);//BindingFlags.Public | BindingFlags.Static | BindingFlags.DeclaredOnly);
       if (createBuilderMethod == null) {
         throw new ArgumentException("No public static CreateBuilder method declared in " + ClrType.Name);
       }
diff --git a/csharp/ProtocolBuffers/FieldSet.cs b/csharp/ProtocolBuffers/FieldSet.cs
index e42b4a01a..bca7e5b54 100644
--- a/csharp/ProtocolBuffers/FieldSet.cs
+++ b/csharp/ProtocolBuffers/FieldSet.cs
@@ -91,11 +91,8 @@ namespace Google.ProtocolBuffers {
     }
 
     // TODO(jonskeet): Should this be in UnknownFieldSet.Builder really? Or CodedInputStream?
-    internal static void MergeFrom(CodedInputStream input,
-         UnknownFieldSet.Builder unknownFields,
-         ExtensionRegistry extensionRegistry,
-         IBuilder builder) {
-
+    internal static void MergeFrom(CodedInputStream input, UnknownFieldSet.Builder unknownFields,
+         ExtensionRegistry extensionRegistry, IBuilder builder) {
       while (true) {
         uint tag = input.ReadTag();
         if (tag == 0) {
@@ -120,15 +117,10 @@ namespace Google.ProtocolBuffers {
     /// <param name="builder">Builder to merge field into, if it's a known field</param>
     /// <param name="tag">The tag, which should already have been read from the input</param>
     /// <returns>true unless the tag is an end-group tag</returns>
-    internal static bool MergeFieldFrom(CodedInputStream input,
-        UnknownFieldSet.Builder unknownFields,
-        ExtensionRegistry extensionRegistry,
-        IBuilder builder,
-        uint tag) {
+    internal static bool MergeFieldFrom(CodedInputStream input, UnknownFieldSet.Builder unknownFields,
+        ExtensionRegistry extensionRegistry, IBuilder builder, uint tag) {
       MessageDescriptor type = builder.DescriptorForType;
-
-      if (type.Options.MessageSetWireFormat
-          && tag == WireFormat.MessageSetTag.ItemStart) {
+      if (type.Options.MessageSetWireFormat && tag == WireFormat.MessageSetTag.ItemStart) {
         MergeMessageSetExtensionFromCodedStream(input, unknownFields, extensionRegistry, builder);
         return true;
       }
diff --git a/csharp/ProtocolBuffers/GeneratedBuilder.cs b/csharp/ProtocolBuffers/GeneratedBuilder.cs
index acafe4861..4b3567d08 100644
--- a/csharp/ProtocolBuffers/GeneratedBuilder.cs
+++ b/csharp/ProtocolBuffers/GeneratedBuilder.cs
@@ -199,6 +199,10 @@ namespace Google.ProtocolBuffers {
       ((IBuilder)this).MergeFrom(input, extensionRegistry);
       return this;
     }
+
+    protected override IBuilder MergeFromImpl(CodedInputStream data, ExtensionRegistry extensionRegistry) {
+      return MergeFrom(data, extensionRegistry);
+    }
     
     /// <summary>
     /// Like Build(), but will wrap UninitializedMessageException in
@@ -222,6 +226,11 @@ namespace Google.ProtocolBuffers {
       }
       return BuildPartial();
     }
+
+    public override UnknownFieldSet UnknownFields {
+      get { return MessageBeingBuilt.UnknownFields; }
+      set { MessageBeingBuilt.SetUnknownFields(value); }
+    }
     
     public abstract TMessage BuildPartial();
     public abstract IBuilder<TMessage> Clone();
diff --git a/csharp/ProtocolBuffers/TextFormat.cs b/csharp/ProtocolBuffers/TextFormat.cs
index e395b5f94..a9a4e1b87 100644
--- a/csharp/ProtocolBuffers/TextFormat.cs
+++ b/csharp/ProtocolBuffers/TextFormat.cs
@@ -187,15 +187,15 @@ namespace Google.ProtocolBuffers {
     }
 
     internal static ulong ParseUInt64(string text) {
-      return (ulong) ParseInteger(text, true, false);
+      return (ulong) ParseInteger(text, false, true);
     }
 
     internal static long ParseInt64(string text) {
-      return ParseInteger(text, true, false);
+      return ParseInteger(text, true, true);
     }
 
     internal static uint ParseUInt32(string text) {
-      return (uint) ParseInteger(text, true, false);
+      return (uint) ParseInteger(text, false, false);
     }
 
     internal static int ParseInt32(string text) {
@@ -229,7 +229,7 @@ namespace Google.ProtocolBuffers {
       ulong result = Convert.ToUInt64(text, radix);
 
       if (negative) {
-        ulong max = isLong ? 0x8000000UL : 0x8000L;
+        ulong max = isLong ? 0x8000000000000000UL : 0x80000000L;
         if (result > max) {
           throw new FormatException("Number of out range: " + original);
         }