Fix support for custom list converters when input is not an array or object

Src/Newtonsoft.Json.Tests/Issues/Issue1576.cs

@@ -0,0 +1,155 @@
+#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.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Serialization;
+#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 Issue1576 : TestFixtureBase
+    {
+        [Test]
+        public void Test()
+        {
+			var settings = new JsonSerializerSettings()
+			{
+				ContractResolver = new CustomContractResolver()
+			};
+
+			var result = JsonConvert.DeserializeObject<TestClass>("{ 'Items': '11' }", settings);
+
+			Assert.IsNotNull(result);
+			Assert.AreEqual(result.Items.Count, 1);
+			Assert.AreEqual(result.Items[0], 11);
+		}
+
+		[Test]
+		public void Test2()
+		{
+			var settings = new JsonSerializerSettings()
+			{
+				Converters = new[] { new OneItemListJsonConverter() }
+			};
+
+			var result = JsonConvert.DeserializeObject<List<int>>("'11'", settings);
+
+			Assert.IsNotNull(result);
+			Assert.AreEqual(result.Count, 1);
+			Assert.AreEqual(result[0], 11);
+		}
+
+		public class TestClass
+        {
+			public List<int> Items { get; } = new List<int>();
+        }
+
+		public class CustomContractResolver : DefaultContractResolver
+		{
+			protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
+			{
+				var property = base.CreateProperty(member, memberSerialization);
+
+				if (member.Name == "Items")
+				{
+					property.Converter = new OneItemListJsonConverter();
+				}
+
+				return property;
+			}
+		}
+
+		public class OneItemListJsonConverter : JsonConverter
+		{
+			public override bool CanWrite => false;
+
+			public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+			{
+				throw new NotSupportedException();
+			}
+
+			public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+			{
+				var recursionBlocked = false;
+				var converter = serializer.Converters.OfType<OneItemListJsonConverter>().FirstOrDefault();
+				if (converter != null)
+				{
+					serializer.Converters.Remove(converter);
+					recursionBlocked = true;
+				}
+
+				try
+				{
+					var token = JToken.Load(reader);
+					if (token.Type == JTokenType.Array)
+					{
+						return token.ToObject(objectType, serializer);
+					}
+
+					var array = new JArray();
+					array.Add(token);
+
+					var list = array.ToObject(objectType, serializer) as IEnumerable;
+					var existing = existingValue as IList;
+
+					if (list != null && existing != null)
+					{
+						foreach (var item in list)
+						{
+							existing.Add(item);
+						}
+					}
+
+					return list;
+				}
+				finally
+				{
+					if (recursionBlocked)
+					{
+						serializer.Converters.Add(converter);
+					}
+				}
+			}
+
+			public override bool CanConvert(Type objectType)
+			{
+				return typeof(IEnumerable).IsAssignableFrom(objectType) && objectType != typeof(string);
+			}
+		}
+
+	}
+}

Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs

@@ -1056,7 +1056,7 @@ namespace Newtonsoft.Json.Serialization
                 property.ObjectCreationHandling.GetValueOrDefault(Serializer._objectCreationHandling);
 
             if ((objectCreationHandling != ObjectCreationHandling.Replace)
-                && (tokenType == JsonToken.StartArray || tokenType == JsonToken.StartObject)
+                && (tokenType == JsonToken.StartArray || tokenType == JsonToken.StartObject || propertyConverter != null)
                 && property.Readable)
             {
                 currentValue = property.ValueProvider.GetValue(target);