Cherrypick for csharp, including:

Add preserve UnknownFields
Compare floating point values bitwise
Add auto-generated header to C# generated files

1 files changed, 18 insertions, 4 deletions

diff --git a/csharp/src/Google.Protobuf/WellKnownTypes/SourceContext.cs b/csharp/src/Google.Protobuf/WellKnownTypes/SourceContext.cs
index 6ddadf19..124ddaa7 100644
--- a/csharp/src/Google.Protobuf/WellKnownTypes/SourceContext.cs
+++ b/csharp/src/Google.Protobuf/WellKnownTypes/SourceContext.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: google/protobuf/source_context.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: google/protobuf/source_context.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -44,6 +46,7 @@ namespace Google.Protobuf.WellKnownTypes {
   /// </summary>
   public sealed partial class SourceContext : pb::IMessage<SourceContext> {
     private static readonly pb::MessageParser<SourceContext> _parser = new pb::MessageParser<SourceContext>(() => new SourceContext());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SourceContext> Parser { get { return _parser; } }
 
@@ -67,6 +70,7 @@ namespace Google.Protobuf.WellKnownTypes {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SourceContext(SourceContext other) : this() {
       fileName_ = other.fileName_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -103,13 +107,16 @@ namespace Google.Protobuf.WellKnownTypes {
         return true;
       }
       if (FileName != other.FileName) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (FileName.Length != 0) hash ^= FileName.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -124,6 +131,9 @@ namespace Google.Protobuf.WellKnownTypes {
         output.WriteRawTag(10);
         output.WriteString(FileName);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -132,6 +142,9 @@ namespace Google.Protobuf.WellKnownTypes {
       if (FileName.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(FileName);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -143,6 +156,7 @@ namespace Google.Protobuf.WellKnownTypes {
       if (other.FileName.Length != 0) {
         FileName = other.FileName;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -151,7 +165,7 @@ namespace Google.Protobuf.WellKnownTypes {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             FileName = input.ReadString();