-Fixed error when deserializing null DataSet or DataTable properties

Src/Newtonsoft.Json.Tests/Converters/DataSetConverterTests.cs

@@ -106,6 +106,53 @@ namespace Newtonsoft.Json.Tests.Converters
             Assert.AreEqual(2, dt.Rows.Count);
         }
 
+        public class DataSetTestClass
+        {
+            public DataSet Set { get; set; }
+        }
+
+        [Test]
+        public void SerializeNull()
+        {
+            DataSetTestClass c1 = new DataSetTestClass
+            {
+                Set = null
+            };
+
+            string json = JsonConvert.SerializeObject(c1, Formatting.Indented);
+
+            StringAssert.AreEqual(@"{
+  ""Set"": null
+}", json);
+
+            DataSetTestClass c2 = JsonConvert.DeserializeObject<DataSetTestClass>(json);
+
+            Assert.AreEqual(null, c2.Set);
+        }
+
+        [Test]
+        public void SerializeNullRoot()
+        {
+            string json = JsonConvert.SerializeObject(null, typeof(DataSet), new JsonSerializerSettings
+            {
+                Formatting = Formatting.Indented
+            });
+
+            StringAssert.AreEqual(@"null", json);
+        }
+
+        [Test]
+        public void DeserializeNullTable()
+        {
+            string json = @"{
+  ""TableName"": null
+}";
+
+            DataSet ds = JsonConvert.DeserializeObject<DataSet>(json);
+
+            Assert.AreEqual(true, ds.Tables.Contains("TableName"));
+        }
+
         [Test]
         public void SerializeMultiTableDataSet()
         {

Src/Newtonsoft.Json.Tests/Converters/DataTableConverterTests.cs

@@ -454,6 +454,41 @@ namespace Newtonsoft.Json.Tests.Converters
             Assert.AreEqual("432", dt[0].CustomerID);
         }
 
+        public class DataTableTestClass
+        {
+            public DataTable Table { get; set; }
+        }
+
+        [Test]
+        public void SerializeNull()
+        {
+            DataTableTestClass c1 = new DataTableTestClass
+            {
+                Table = null
+            };
+
+            string json = JsonConvert.SerializeObject(c1, Formatting.Indented);
+
+            StringAssert.AreEqual(@"{
+  ""Table"": null
+}", json);
+
+            DataTableTestClass c2 = JsonConvert.DeserializeObject<DataTableTestClass>(json);
+
+            Assert.AreEqual(null, c2.Table);
+        }
+
+        [Test]
+        public void SerializeNullRoot()
+        {
+            string json = JsonConvert.SerializeObject(null, typeof(DataTable), new JsonSerializerSettings
+            {
+                Formatting = Formatting.Indented
+            });
+
+            StringAssert.AreEqual(@"null", json);
+        }
+
 #if !(NET20 || PORTABLE || PORTABLE40)
         [Test]
         public void DeserializedTypedDataTableWithConverter()

Src/Newtonsoft.Json/Converters/DataSetConverter.cs

@@ -70,6 +70,11 @@ namespace Newtonsoft.Json.Converters
         /// <returns>The object value.</returns>
         public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
         {
+            if (reader.TokenType == JsonToken.Null)
+            {
+                return null;
+            }
+
             // handle typed datasets
             DataSet ds = (objectType == typeof(DataSet))
                 ? new DataSet()
@@ -87,7 +92,9 @@ namespace Newtonsoft.Json.Converters
                 dt = (DataTable)converter.ReadJson(reader, typeof(DataTable), dt, serializer);
 
                 if (!exists)
+                {
                     ds.Tables.Add(dt);
+                }
 
                 CheckedRead(reader);
             }
@@ -110,9 +117,10 @@ namespace Newtonsoft.Json.Converters
         private void CheckedRead(JsonReader reader)
         {
             if (!reader.Read())
+            {
                 throw JsonSerializationException.Create(reader, "Unexpected end when reading DataSet.");
+            }
         }
     }
 }
-
 #endif

Src/Newtonsoft.Json/Converters/DataTableConverter.cs

@@ -80,6 +80,11 @@ namespace Newtonsoft.Json.Converters
         /// <returns>The object value.</returns>
         public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
         {
+            if (reader.TokenType == JsonToken.Null)
+            {
+                return null;
+            }
+
             DataTable dt = existingValue as DataTable;
 
             if (dt == null)
@@ -90,15 +95,24 @@ namespace Newtonsoft.Json.Converters
                     : (DataTable)Activator.CreateInstance(objectType);
             }
 
+            // DataTable is inside a DataSet
+            // populate the name from the property name
             if (reader.TokenType == JsonToken.PropertyName)
             {
                 dt.TableName = (string)reader.Value;
 
                 CheckedRead(reader);
+
+                if (reader.TokenType == JsonToken.Null)
+                {
+                    return dt;
+                }
             }
 
             if (reader.TokenType != JsonToken.StartArray)
+            {
                 throw JsonSerializationException.Create(reader, "Unexpected JSON token when reading DataTable. Expected StartArray, got {0}.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
+            }
 
             CheckedRead(reader);
 
@@ -134,7 +148,9 @@ namespace Newtonsoft.Json.Converters
                 if (column.DataType == typeof(DataTable))
                 {
                     if (reader.TokenType == JsonToken.StartArray)
+                    {
                         CheckedRead(reader);
+                    }
 
                     DataTable nestedDt = new DataTable();
 
@@ -150,7 +166,9 @@ namespace Newtonsoft.Json.Converters
                 else if (column.DataType.IsArray && column.DataType != typeof(byte[]))
                 {
                     if (reader.TokenType == JsonToken.StartArray)
+                    {
                         CheckedRead(reader);
+                    }
 
                     List<object> o = new List<object>();
 
@@ -196,7 +214,9 @@ namespace Newtonsoft.Json.Converters
                 case JsonToken.StartArray:
                     CheckedRead(reader);
                     if (reader.TokenType == JsonToken.StartObject)
-                        return typeof(DataTable); // nested datatable
+                    {
+                        return typeof (DataTable); // nested datatable
+                    }
 
                     Type arrayType = GetColumnDataType(reader);
                     return arrayType.MakeArrayType();
@@ -208,7 +228,9 @@ namespace Newtonsoft.Json.Converters
         private static void CheckedRead(JsonReader reader)
         {
             if (!reader.Read())
+            {
                 throw JsonSerializationException.Create(reader, "Unexpected end when reading DataTable.");
+            }
         }
 
         /// <summary>