-Fix deserializing nullable array

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

@@ -3353,5 +3353,24 @@ keyword such as type of business.""
 
       Assert.AreEqual(2, newDictionary.Count);
     }
+
+    [Test]
+    public void SerializeNullableArray()
+    {
+      string jsonText = JsonConvert.SerializeObject(new double?[] { 2.4, 4.3, null }, Formatting.Indented);
+
+      Assert.AreEqual(@"[
+  2.4,
+  4.3,
+  null
+]", jsonText);
+
+      double?[] d = (double?[])JsonConvert.DeserializeObject(jsonText, typeof(double?[]));
+
+      Assert.AreEqual(3, d.Length);
+      Assert.AreEqual(2.4, d[0]);
+      Assert.AreEqual(4.3, d[1]);
+      Assert.AreEqual(null, d[2]);
+    }
   }
 }

Src/Newtonsoft.Json/Serialization/JsonArrayContract.cs

@@ -70,7 +70,8 @@ namespace Newtonsoft.Json.Serialization
 
     internal IWrappedCollection CreateWrapper(object list)
     {
-      if (list is IList && (CollectionItemType == null || !_isCollectionItemTypeNullableType))
+      if ((list is IList && (CollectionItemType == null || !_isCollectionItemTypeNullableType))
+        || UnderlyingType.IsArray)
         return new CollectionWrapper<object>((IList)list);
 
       if (_genericWrapperType == null)