From a213bac448e2543339694a6dbca6d2edef787701 Mon Sep 17 00:00:00 2001
From: James Newton-King <james@newtonking.com>
Date: Sun, 8 Sep 2019 20:46:20 +1200
Subject: [PATCH] Fix deserialize via ctor with some existing collection types
 (#2151)

---
 .../JsonSerializerCollectionsTests.cs         | 23 +++++++++++++++++++
 .../JsonSerializerInternalReader.cs           | 15 ++++++++----
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerCollectionsTests.cs b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerCollectionsTests.cs
index c3678e56..631cd6ec 100644
--- a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerCollectionsTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerCollectionsTests.cs
@@ -62,6 +62,29 @@ namespace Newtonsoft.Json.Tests.Serialization
     public class JsonSerializerCollectionsTests : TestFixtureBase
     {
 #if !(NET35 || NET20 || PORTABLE || PORTABLE40) || NETSTANDARD2_0
+        [Test]
+        public void DeserializeNonGenericListTypeAndReadOnlyListViaConstructor()
+        {
+            ConstructorCollectionContainer a = JsonConvert.DeserializeObject<ConstructorCollectionContainer>("{'a':1,'b':['aaa'],'c':['aaa']}");
+
+            Assert.AreEqual(1, a.A);
+            Assert.AreEqual(1, a.B.Count());
+            Assert.AreEqual("aaa", a.B.ElementAt(0));
+            Assert.AreEqual(0, a.C.Count());
+        }
+
+        public class ConstructorCollectionContainer
+        {
+            public int A { get; }
+            public IEnumerable<string> B { get; } = new SortedSet<string>();
+            public IEnumerable<string> C { get; } = new List<string>().AsReadOnly();
+
+            public ConstructorCollectionContainer(int a)
+            {
+                this.A = a;
+            }
+        }
+
         [Test]
         public void DeserializeConcurrentDictionaryWithNullValue()
         {
diff --git a/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs b/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs
index 7b6c9ed3..5cb82550 100644
--- a/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs
+++ b/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs
@@ -2079,12 +2079,19 @@ namespace Newtonsoft.Json.Serialization
                             object? createdObjectCollection = property.ValueProvider!.GetValue(createdObject);
                             if (createdObjectCollection != null)
                             {
-                                IList createdObjectCollectionWrapper = (propertyArrayContract.ShouldCreateWrapper) ? propertyArrayContract.CreateWrapper(createdObjectCollection) : (IList)createdObjectCollection;
-                                IList newValues = (propertyArrayContract.ShouldCreateWrapper) ? propertyArrayContract.CreateWrapper(value) : (IList)value;
+                                propertyArrayContract = (JsonArrayContract)GetContract(createdObjectCollection.GetType());
 
-                                foreach (object newValue in newValues)
+                                IList createdObjectCollectionWrapper = (propertyArrayContract.ShouldCreateWrapper) ? propertyArrayContract.CreateWrapper(createdObjectCollection) : (IList)createdObjectCollection;
+
+                                // Don't attempt to populate array/read-only list
+                                if (!createdObjectCollectionWrapper.IsFixedSize)
                                 {
-                                    createdObjectCollectionWrapper.Add(newValue);
+                                    IList newValues = (propertyArrayContract.ShouldCreateWrapper) ? propertyArrayContract.CreateWrapper(value) : (IList)value;
+
+                                    foreach (object newValue in newValues)
+                                    {
+                                        createdObjectCollectionWrapper.Add(newValue);
+                                    }
                                 }
                             }
                         }