From 9335f00628be416c95ef4d93b543966353ea8982 Mon Sep 17 00:00:00 2001
From: Shay Rojansky <roji@eaglets.co.il>
Date: Sun, 5 May 2013 09:40:10 +0100
Subject: [PATCH] Null is now properly deserialized

The deserializer wasn't recognizing null literals as such (~, empty
string, null, Null, NULL). As a result, a null string was deserialized
as an empty string. Added a test for this (roundtrip + emit defaults).
---
 .../Serialization/YamlSerializer.cs           | 16 +++++-----
 .../RepresentationModel/SerializationTests.cs | 29 +++++++++++++++++++
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/YamlDotNet.RepresentationModel/Serialization/YamlSerializer.cs b/YamlDotNet.RepresentationModel/Serialization/YamlSerializer.cs
index 8121ecf..549eef5 100644
--- a/YamlDotNet.RepresentationModel/Serialization/YamlSerializer.cs
+++ b/YamlDotNet.RepresentationModel/Serialization/YamlSerializer.cs
@@ -335,21 +335,19 @@ namespace YamlDotNet.RepresentationModel.Serialization
 
 		private bool IsNull(NodeEvent nodeEvent)
 		{
+			// http://yaml.org/type/null.html
+
 			if (nodeEvent.Tag == "tag:yaml.org,2002:null")
 			{
 				return true;
 			}
 
-			if (JsonCompatible)
-			{
-				var scalar = nodeEvent as Scalar;
-				if (scalar != null && scalar.Style == Core.ScalarStyle.Plain && scalar.Value == "null")
-				{
-					return true;
-				}
-			}
+			var scalar = nodeEvent as Scalar;
+			if (scalar == null)
+				return false;
 
-			return false;
+			var value = scalar.Value;
+			return value == "" || value == "~" || value == "null" || value == "Null" || value == "NULL";
 		}
 
 		private object DeserializeValueNotNull(EventReader reader, DeserializationContext context, INodeEvent nodeEvent, Type expectedType)
diff --git a/YamlDotNet.UnitTests/RepresentationModel/SerializationTests.cs b/YamlDotNet.UnitTests/RepresentationModel/SerializationTests.cs
index 12c4e36..2750952 100644
--- a/YamlDotNet.UnitTests/RepresentationModel/SerializationTests.cs
+++ b/YamlDotNet.UnitTests/RepresentationModel/SerializationTests.cs
@@ -197,6 +197,35 @@ namespace YamlDotNet.UnitTests.RepresentationModel
 			}
 		}
 
+		[Fact]
+		public void RoundtripWithDefaults()
+		{
+			var serializer = new Serializer();
+
+			using (StringWriter buffer = new StringWriter())
+			{
+				X original = new X();
+				serializer.Serialize(buffer, original, SerializationOptions.Roundtrip | SerializationOptions.EmitDefaults);
+
+				Console.WriteLine(buffer.ToString());
+
+				var deserializer = new YamlSerializer(typeof(X), YamlSerializerModes.Roundtrip);
+				X copy = (X)deserializer.Deserialize(new StringReader(buffer.ToString()));
+
+				foreach (var property in typeof(X).GetProperties(BindingFlags.Public | BindingFlags.Instance))
+				{
+					if (property.CanRead && property.CanWrite)
+					{
+						Assert.Equal(
+							property.GetValue(original, null),
+							property.GetValue(copy, null)
+						);
+					}
+				}
+			}
+		}
+
+
 		private class Y
 		{
 			private Y child;