-Fixed JToken.ReadFrom creating a string value for a comment

Src/Newtonsoft.Json.Tests/Linq/JObjectTests.cs

@@ -57,6 +57,23 @@ namespace Newtonsoft.Json.Tests.Linq
     [TestFixture]
     public class JObjectTests : TestFixtureBase
     {
+        [Test]
+        public void EmbedJValueStringInNewJObject()
+        {
+            string s = null;
+            var v = new JValue(s);
+            dynamic o = JObject.FromObject(new { title = v });
+
+            string output = o.ToString();
+
+            Assert.AreEqual(@"{
+  ""title"": null
+}", output);
+
+            Assert.AreEqual(null, v.Value);
+            Assert.IsNull((string)o.title);
+        }
+
         [Test]
         public void JObjectWithComments()
         {

Src/Newtonsoft.Json.Tests/Linq/LinqToJsonTest.cs

@@ -49,6 +49,81 @@ namespace Newtonsoft.Json.Tests.Linq
     [TestFixture]
     public class LinqToJsonTest : TestFixtureBase
     {
+        [Test]
+        public void CommentsAndReadFrom()
+        {
+            StringReader textReader = new StringReader(@"[
+    // hi
+    1,
+    2,
+    3
+]");
+
+            JsonTextReader jsonReader = new JsonTextReader(textReader);
+            JArray a = (JArray)JToken.ReadFrom(jsonReader);
+
+            Assert.AreEqual(4, a.Count);
+            Assert.AreEqual(JTokenType.Comment, a[0].Type);
+            Assert.AreEqual(" hi", ((JValue)a[0]).Value);
+        }
+
+        [Test]
+        public void StartingCommentAndReadFrom()
+        {
+            StringReader textReader = new StringReader(@"
+// hi
+[
+    1,
+    2,
+    3
+]");
+
+            JsonTextReader jsonReader = new JsonTextReader(textReader);
+            JValue v = (JValue)JToken.ReadFrom(jsonReader);
+
+            Assert.AreEqual(JTokenType.Comment, v.Type);
+
+            IJsonLineInfo lineInfo = v;
+            Assert.AreEqual(true, lineInfo.HasLineInfo());
+            Assert.AreEqual(3, lineInfo.LineNumber);
+            Assert.AreEqual(1, lineInfo.LinePosition);
+        }
+
+        [Test]
+        public void StartingUndefinedAndReadFrom()
+        {
+            StringReader textReader = new StringReader(@"
+undefined
+[
+    1,
+    2,
+    3
+]");
+
+            JsonTextReader jsonReader = new JsonTextReader(textReader);
+            JValue v = (JValue)JToken.ReadFrom(jsonReader);
+
+            Assert.AreEqual(JTokenType.Undefined, v.Type);
+
+            IJsonLineInfo lineInfo = v;
+            Assert.AreEqual(true, lineInfo.HasLineInfo());
+            Assert.AreEqual(2, lineInfo.LineNumber);
+            Assert.AreEqual(10, lineInfo.LinePosition);
+        }
+
+        [Test]
+        public void StartingEndArrayAndReadFrom()
+        {
+            StringReader textReader = new StringReader(@"[]");
+
+            JsonTextReader jsonReader = new JsonTextReader(textReader);
+            jsonReader.Read();
+            jsonReader.Read();
+
+            ExceptionAssert.Throws<JsonReaderException>(@"Error reading JToken from JsonReader. Unexpected token: EndArray. Path '', line 1, position 2.",
+                () => JToken.ReadFrom(jsonReader));
+        }
+
         [Test]
         public void JPropertyPath()
         {

Src/Newtonsoft.Json/Linq/JToken.cs

@@ -1835,22 +1835,42 @@ namespace Newtonsoft.Json.Linq
                     throw JsonReaderException.Create(reader, "Error reading JToken from JsonReader.");
             }
 
-            if (reader.TokenType == JsonToken.StartObject)
-                return JObject.Load(reader);
+            IJsonLineInfo lineInfo = reader as IJsonLineInfo;
 
-            if (reader.TokenType == JsonToken.StartArray)
-                return JArray.Load(reader);
-
-            if (reader.TokenType == JsonToken.PropertyName)
-                return JProperty.Load(reader);
-
-            if (reader.TokenType == JsonToken.StartConstructor)
-                return JConstructor.Load(reader);
-
-            if (!JsonReader.IsStartToken(reader.TokenType))
-                return new JValue(reader.Value);
-
-            throw JsonReaderException.Create(reader, "Error reading JToken from JsonReader. Unexpected token: {0}".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
+            switch (reader.TokenType)
+            {
+                case JsonToken.StartObject:
+                    return JObject.Load(reader);
+                case JsonToken.StartArray:
+                    return JArray.Load(reader);
+                case JsonToken.StartConstructor:
+                    return JConstructor.Load(reader);
+                case JsonToken.PropertyName:
+                    return JProperty.Load(reader);
+                case JsonToken.String:
+                case JsonToken.Integer:
+                case JsonToken.Float:
+                case JsonToken.Date:
+                case JsonToken.Boolean:
+                case JsonToken.Bytes:
+                    JValue v = new JValue(reader.Value);
+                    v.SetLineInfo(lineInfo);
+                    return v;
+                case JsonToken.Comment:
+                    v = JValue.CreateComment(reader.Value.ToString());
+                    v.SetLineInfo(lineInfo);
+                    return v;
+                case JsonToken.Null:
+                    v = new JValue(null, JTokenType.Null);
+                    v.SetLineInfo(lineInfo);
+                    return v;
+                case JsonToken.Undefined:
+                    v = new JValue(null, JTokenType.Undefined);
+                    v.SetLineInfo(lineInfo);
+                    return v;
+                default:
+                    throw JsonReaderException.Create(reader, "Error reading JToken from JsonReader. Unexpected token: {0}".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
+            }
         }
 
         /// <summary>