Cherrypick for csharp, including:

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

1 files changed, 11 insertions, 0 deletions

diff --git a/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs b/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
index 5b7185dc..8ed55744 100644
--- a/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
+++ b/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
@@ -417,5 +417,16 @@ namespace Google.Protobuf.WellKnownTypes
             TestWellKnownTypes.Descriptor.Fields[TestWellKnownTypes.StringFieldFieldNumber].Accessor.Clear(message);
             Assert.IsNull(message.StringField);
         }
+
+        [Test]
+        public void NaNComparisons()
+        {
+            var message1 = new TestWellKnownTypes { DoubleField = SampleNaNs.Regular };
+            var message2 = new TestWellKnownTypes { DoubleField = SampleNaNs.PayloadFlipped };
+            var message3 = new TestWellKnownTypes { DoubleField = SampleNaNs.Regular };
+
+            EqualityTester.AssertInequality(message1, message2);
+            EqualityTester.AssertEquality(message1, message3);
+        }
     }
 }