-Fixed List<T> silly buggers with nullable types - http://tinyurl.com/yagsptj - That was tough!

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

@@ -2227,5 +2227,16 @@ keyword such as type of business.""
 
       list l = JsonConvert.DeserializeObject<list>(json);
     }
+
+    [Test]
+    public void sdfsdf()
+    {
+      //List<decimal?> l = new List<decimal?>();
+      //l.Add(null);
+      //IList il = l;
+      //il.Add(null);
+
+      JsonConvert.DeserializeObject<List<decimal?>>("[ 3.3, null, 1.1 ] ");
+    }
   }
 }

Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs

@@ -502,12 +502,14 @@ namespace Newtonsoft.Json.Serialization
             throw new JsonSerializationException("Cannot call OnError on an array or readonly list: {0}".FormatWith(CultureInfo.InvariantCulture, contract.UnderlyingType));
 #endif
 
-          PopulateList(l, reader, reference, contract);
+          PopulateList(CollectionUtils.CreateCollectionWrapper(l), reader, reference, contract);
         });
     }
 
-    private IList PopulateList(IList list, JsonReader reader, string reference, JsonArrayContract contract)
+    private object PopulateList(IWrappedCollection wrappedList, JsonReader reader, string reference, JsonArrayContract contract)
     {
+      object list = wrappedList.UnderlyingCollection;
+
       if (reference != null)
         _serializer.ReferenceResolver.AddReference(reference, list);
 
@@ -522,7 +524,7 @@ namespace Newtonsoft.Json.Serialization
           case JsonToken.EndArray:
             contract.InvokeOnDeserialized(list);
 
-            return list;
+            return wrappedList.UnderlyingCollection;
           case JsonToken.Comment:
             break;
           default:
@@ -530,12 +532,12 @@ namespace Newtonsoft.Json.Serialization
             {
               object value = CreateValue(reader, contract.CollectionItemType, null, null);
 
-              list.Add(value);
+              wrappedList.Add(value);
             }
             catch (Exception ex)
             {
 #if !PocketPC && !SILVERLIGHT && !NET20
-              ErrorContext errorContext = GetErrorContext(list, list.Count, ex);
+              ErrorContext errorContext = GetErrorContext(list, wrappedList.Count, ex);
               contract.InvokeOnError(list, errorContext);
 
               if (errorContext.Handled)

Src/Newtonsoft.Json/Utilities/CollectionUtils.cs

@@ -525,7 +525,7 @@ namespace Newtonsoft.Json.Utilities
 
         // can't add or modify a readonly list
         // use List<T> and convert once populated
-        list = (IList)CreateGenericList(readOnlyCollectionContentsType);
+        list = CreateGenericList(readOnlyCollectionContentsType);
         isReadOnlyOrFixedSize = true;
       }
       else if (typeof(IList).IsAssignableFrom(listType))
@@ -537,9 +537,9 @@ namespace Newtonsoft.Json.Utilities
         else
           list = null;
       }
-      else if (listType.IsGenericType && listType.GetGenericTypeDefinition() == typeof(IList<>))
+      else if (ReflectionUtils.ImplementsGenericDefinition(listType, typeof(IList<>)))
       {
-        list = CollectionUtils.CreateGenericList(ReflectionUtils.GetCollectionItemType(listType));
+        list = CreateGenericList(ReflectionUtils.GetCollectionItemType(listType));
       }
       else
       {

Src/Newtonsoft.Json/Utilities/CollectionWrapper.cs

@@ -48,7 +48,10 @@ namespace Newtonsoft.Json.Utilities
     {
       ValidationUtils.ArgumentNotNull(list, "list");
 
-      _list = list;
+      if (list is ICollection<T>)
+        _genericCollection = (ICollection<T>)list;
+      else
+        _list = list;
     }
 
     public CollectionWrapper(ICollection<T> list)
@@ -248,7 +251,7 @@ namespace Newtonsoft.Json.Utilities
 
     private static bool IsCompatibleObject(object value)
     {
-      if (!(value is T) && (value != null || typeof(T).IsValueType))
+      if (!(value is T) && (value != null || (typeof(T).IsValueType && !ReflectionUtils.IsNullableType(typeof(T)))))
         return false;
 
       return true;

Src/Newtonsoft.Json/Utilities/ListWrapper.cs

@@ -48,7 +48,10 @@ namespace Newtonsoft.Json.Utilities
     {
       ValidationUtils.ArgumentNotNull(list, "list");
 
-      _list = list;
+      if (list is IList<T>)
+        _genericList = (IList<T>) list;
+      else
+        _list = list;
     }
 
     public ListWrapper(IList<T> list)
@@ -267,7 +270,7 @@ namespace Newtonsoft.Json.Utilities
 
     private static bool IsCompatibleObject(object value)
     {
-      if (!(value is T) && (value != null || typeof(T).IsValueType))
+      if (!(value is T) && (value != null || (typeof(T).IsValueType && !ReflectionUtils.IsNullableType(typeof(T)))))
         return false;
 
       return true;