-Fixed deserializing with a TraceWriter when the reader is not at the start

Src/Newtonsoft.Json.Tests/Serialization/TraceWriterTests.cs

@@ -33,7 +33,7 @@ using System.Threading.Tasks;
 #endif
 
 namespace Newtonsoft.Json.Tests.Serialization
-{
+{ 
     public class Staff
     {
         public string Name { get; set; }
@@ -41,9 +41,86 @@ namespace Newtonsoft.Json.Tests.Serialization
         public IList<string> Roles { get; set; }
     }
 
+    public class RoleTrace
+    {
+        public string Name { get; set; }
+    }
+
     [TestFixture]
     public class TraceWriterTests : TestFixtureBase
     {
+        [Test]
+        public void DeserializedJsonWithAlreadyReadReader()
+        {
+            string json = @"{ 'name': 'Admin' }{ 'name': 'Publisher' }";
+            IList<RoleTrace> roles = new List<RoleTrace>();
+            JsonTextReader reader = new JsonTextReader(new StringReader(json));
+            reader.SupportMultipleContent = true;
+            InMemoryTraceWriter traceWriter = new InMemoryTraceWriter();
+            while (true)
+            {
+                if (!reader.Read())
+                {
+                    break;
+                }
+                JsonSerializer serializer = new JsonSerializer();
+                //the next line raise an exception
+                serializer.TraceWriter = traceWriter;
+                RoleTrace role = serializer.Deserialize<RoleTrace>(reader);
+                roles.Add(role);
+            }
+
+            Assert.AreEqual("Admin", roles[0].Name);
+            Assert.AreEqual("Publisher", roles[1].Name);
+
+            StringAssert.AreEqual(@"Deserialized JSON: 
+{
+  ""name"": ""Admin""
+}", traceWriter.TraceRecords[2].Message);
+
+            StringAssert.AreEqual(@"Deserialized JSON: 
+{
+  ""name"": ""Publisher""
+}", traceWriter.TraceRecords[5].Message);
+        }
+
+#if !(NET20 || NET35 || NET40 || PORTABLE40 || PORTABLE) || DNXCORE50
+        [Test]
+        public async Task DeserializedJsonWithAlreadyReadReader_Async()
+        {
+            string json = @"{ 'name': 'Admin' }{ 'name': 'Publisher' }";
+            IList<RoleTrace> roles = new List<RoleTrace>();
+            JsonTextReader reader = new JsonTextReader(new StringReader(json));
+            reader.SupportMultipleContent = true;
+            InMemoryTraceWriter traceWriter = new InMemoryTraceWriter();
+            while (true)
+            {
+                if (!await reader.ReadAsync())
+                {
+                    break;
+                }
+                JsonSerializer serializer = new JsonSerializer();
+                //the next line raise an exception
+                serializer.TraceWriter = traceWriter;
+                RoleTrace role = serializer.Deserialize<RoleTrace>(reader);
+                roles.Add(role);
+            }
+
+            Assert.AreEqual("Admin", roles[0].Name);
+            Assert.AreEqual("Publisher", roles[1].Name);
+
+            StringAssert.AreEqual(@"Deserialized JSON: 
+{
+  ""name"": ""Admin""
+}", traceWriter.TraceRecords[2].Message);
+
+            StringAssert.AreEqual(@"Deserialized JSON: 
+{
+  ""name"": ""Publisher""
+}", traceWriter.TraceRecords[5].Message);
+        }
+#endif
+
 #if !(PORTABLE || DNXCORE50 || PORTABLE40) || NETSTANDARD2_0
         [Test]
         public void DiagnosticsTraceWriterTest()

Src/Newtonsoft.Json/JsonSerializer.cs

@@ -798,7 +798,7 @@ namespace Newtonsoft.Json
             SetupReader(reader, out previousCulture, out previousDateTimeZoneHandling, out previousDateParseHandling, out previousFloatParseHandling, out previousMaxDepth, out previousDateFormatString);
 
             TraceJsonReader traceJsonReader = (TraceWriter != null && TraceWriter.LevelFilter >= TraceLevel.Verbose)
-                ? new TraceJsonReader(reader)
+                ? CreateTraceJsonReader(reader)
                 : null;
 
             JsonSerializerInternalReader serializerReader = new JsonSerializerInternalReader(this);
@@ -872,7 +872,7 @@ namespace Newtonsoft.Json
             SetupReader(reader, out previousCulture, out previousDateTimeZoneHandling, out previousDateParseHandling, out previousFloatParseHandling, out previousMaxDepth, out previousDateFormatString);
 
             TraceJsonReader traceJsonReader = (TraceWriter != null && TraceWriter.LevelFilter >= TraceLevel.Verbose)
-                ? new TraceJsonReader(reader)
+                ? CreateTraceJsonReader(reader)
                 : null;
 
             JsonSerializerInternalReader serializerReader = new JsonSerializerInternalReader(this);
@@ -1050,6 +1050,17 @@ namespace Newtonsoft.Json
             SerializeInternal(jsonWriter, value, null);
         }
 
+        private TraceJsonReader CreateTraceJsonReader(JsonReader reader)
+        {
+            TraceJsonReader traceReader = new TraceJsonReader(reader);
+            if (reader.TokenType != JsonToken.None)
+            {
+                traceReader.WriteCurrentToken();
+            }
+
+            return traceReader;
+        }
+
         internal virtual void SerializeInternal(JsonWriter jsonWriter, object value, Type objectType)
         {
             ValidationUtils.ArgumentNotNull(jsonWriter, nameof(jsonWriter));

Src/Newtonsoft.Json/Serialization/TraceJsonReader.cs

@@ -32,56 +32,56 @@ namespace Newtonsoft.Json.Serialization
         public override bool Read()
         {
             bool value = _innerReader.Read();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override int? ReadAsInt32()
         {
             int? value = _innerReader.ReadAsInt32();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override string ReadAsString()
         {
             string value = _innerReader.ReadAsString();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override byte[] ReadAsBytes()
         {
             byte[] value = _innerReader.ReadAsBytes();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override decimal? ReadAsDecimal()
         {
             decimal? value = _innerReader.ReadAsDecimal();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override double? ReadAsDouble()
         {
             double? value = _innerReader.ReadAsDouble();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override bool? ReadAsBoolean()
         {
             bool? value = _innerReader.ReadAsBoolean();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
         public override DateTime? ReadAsDateTime()
         {
             DateTime? value = _innerReader.ReadAsDateTime();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 
@@ -89,11 +89,16 @@ namespace Newtonsoft.Json.Serialization
         public override DateTimeOffset? ReadAsDateTimeOffset()
         {
             DateTimeOffset? value = _innerReader.ReadAsDateTimeOffset();
-            _textWriter.WriteToken(_innerReader, false, false, true);
+            WriteCurrentToken();
             return value;
         }
 #endif
 
+        public void WriteCurrentToken()
+        {
+            _textWriter.WriteToken(_innerReader, false, false, true);
+        }
+
         public override int Depth
         {
             get { return _innerReader.Depth; }