From baa1e21612cae4fb3d3b495e022e327afa50b946 Mon Sep 17 00:00:00 2001
From: James Newton-King <james@newtonking.com>
Date: Mon, 30 Sep 2019 16:34:39 +1300
Subject: [PATCH] Fix deserializing incomplete JSON object to JObject (#2181)

---
 Src/Newtonsoft.Json.Tests/Issues/Issue2165.cs | 83 +++++++++++++++++++
 Src/Newtonsoft.Json/JsonWriter.Async.cs       |  2 +-
 Src/Newtonsoft.Json/JsonWriter.cs             |  9 +-
 3 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 Src/Newtonsoft.Json.Tests/Issues/Issue2165.cs

diff --git a/Src/Newtonsoft.Json.Tests/Issues/Issue2165.cs b/Src/Newtonsoft.Json.Tests/Issues/Issue2165.cs
new file mode 100644
index 000000000..64071d4e4
--- /dev/null
+++ b/Src/Newtonsoft.Json.Tests/Issues/Issue2165.cs
@@ -0,0 +1,83 @@
+#region License
+// Copyright (c) 2007 James Newton-King
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+#endregion
+
+using System;
+using System.IO;
+#if !(NET20 || NET35 || NET40 || PORTABLE40)
+using System.Threading.Tasks;
+#endif
+using Newtonsoft.Json.Linq;
+#if DNXCORE50
+using Xunit;
+using Test = Xunit.FactAttribute;
+using Assert = Newtonsoft.Json.Tests.XUnitAssert;
+#else
+using NUnit.Framework;
+#endif
+
+namespace Newtonsoft.Json.Tests.Issues
+{
+    [TestFixture]
+    public class Issue2165
+    {
+        [Test]
+        public void Test_Deserializer()
+        {
+            ExceptionAssert.Throws<JsonWriterException>(
+                () => JsonConvert.DeserializeObject<JObject>("{"),
+                "Unexpected end when reading token. Path ''.");
+        }
+
+        [Test]
+        public void Test()
+        {
+            StringWriter w = new StringWriter();
+            JsonTextWriter writer = new JsonTextWriter(w);
+
+            var jsonReader = new JsonTextReader(new StringReader("{"));
+            jsonReader.Read();
+
+            ExceptionAssert.Throws<JsonWriterException>(
+                () => writer.WriteToken(jsonReader),
+                "Unexpected end when reading token. Path ''.");
+        }
+
+#if !(NET20 || NET35 || NET40 || PORTABLE40)
+        [Test]
+        public async Task TestAsync()
+        {
+            StringWriter w = new StringWriter();
+            JsonTextWriter writer = new JsonTextWriter(w);
+
+            var jsonReader = new JsonTextReader(new StringReader("{"));
+            await jsonReader.ReadAsync();
+
+            await ExceptionAssert.ThrowsAsync<JsonWriterException>(
+                () => writer.WriteTokenAsync(jsonReader),
+                "Unexpected end when reading token. Path ''.");
+        }
+#endif
+    }
+}
diff --git a/Src/Newtonsoft.Json/JsonWriter.Async.cs b/Src/Newtonsoft.Json/JsonWriter.Async.cs
index 47c6325e4..750d29271 100644
--- a/Src/Newtonsoft.Json/JsonWriter.Async.cs
+++ b/Src/Newtonsoft.Json/JsonWriter.Async.cs
@@ -785,7 +785,7 @@ internal virtual async Task WriteTokenAsync(JsonReader reader, bool writeChildre
                 && writeChildren
                 && await reader.ReadAsync(cancellationToken).ConfigureAwait(false));
 
-            if (initialDepth < CalculateWriteTokenFinalDepth(reader))
+            if (IsWriteTokenIncomplete(reader, writeChildren, initialDepth))
             {
                 throw JsonWriterException.Create(this, "Unexpected end when reading token.", null);
             }
diff --git a/Src/Newtonsoft.Json/JsonWriter.cs b/Src/Newtonsoft.Json/JsonWriter.cs
index 893ecb3f2..b1fbc15cf 100644
--- a/Src/Newtonsoft.Json/JsonWriter.cs
+++ b/Src/Newtonsoft.Json/JsonWriter.cs
@@ -666,12 +666,19 @@ internal virtual void WriteToken(JsonReader reader, bool writeChildren, bool wri
                 && writeChildren
                 && reader.Read());
 
-            if (initialDepth < CalculateWriteTokenFinalDepth(reader))
+            if (IsWriteTokenIncomplete(reader, writeChildren, initialDepth))
             {
                 throw JsonWriterException.Create(this, "Unexpected end when reading token.", null);
             }
         }
 
+        private bool IsWriteTokenIncomplete(JsonReader reader, bool writeChildren, int initialDepth)
+        {
+            int finalDepth = CalculateWriteTokenFinalDepth(reader);
+            return initialDepth < finalDepth ||
+                (writeChildren && initialDepth == finalDepth && JsonTokenUtils.IsStartToken(reader.TokenType));
+        }
+
         private int CalculateWriteTokenInitialDepth(JsonReader reader)
         {
             JsonToken type = reader.TokenType;