Fixes for .NET 3.5 compatibility

* Changing DOTNET35 framework symbols in preprocessor directives to the default built-in value of NET35.
* Adding extension method StreamExtension.CopyTo for .NET 3.5 because it didn’t exist until .NET 4, and adding associated unit tests.

1 files changed, 4 insertions, 1 deletions

diff --git a/csharp/src/Google.Protobuf.Test/FieldCodecTest.cs b/csharp/src/Google.Protobuf.Test/FieldCodecTest.cs
index 0e2bad59..77641163 100644..100755
--- a/csharp/src/Google.Protobuf.Test/FieldCodecTest.cs
+++ b/csharp/src/Google.Protobuf.Test/FieldCodecTest.cs
@@ -158,7 +158,9 @@ namespace Google.Protobuf
             {
                 // WriteTagAndValue ignores default values
                 var stream = new MemoryStream();
-                var codedOutput = new CodedOutputStream(stream);
+                CodedOutputStream codedOutput;

+#if !NET35
+                codedOutput = new CodedOutputStream(stream);
                 codec.WriteTagAndValue(codedOutput, codec.DefaultValue);
                 codedOutput.Flush();
                 Assert.AreEqual(0, stream.Position);
@@ -167,6 +169,7 @@ namespace Google.Protobuf
                 {
                     Assert.AreEqual(default(T), codec.DefaultValue);
                 }
+#endif
 
                 // The plain ValueWriter/ValueReader delegates don't.
                 if (codec.DefaultValue != null) // This part isn't appropriate for message types.