From 6d7ac143134850c8ecfc1d20403cd3c16e23cff1 Mon Sep 17 00:00:00 2001
From: James Newton-King <james@newtonking.com>
Date: Wed, 20 Jul 2016 14:09:56 +1200
Subject: [PATCH] -Fixed DynamicReflectionDelegateFactory creating typed value
 type constructors

---
 .../DynamicReflectionDelegateFactoryTests.cs  | 23 +++++++++++++++++++
 ...xpressionReflectionDelegateFactoryTests.cs | 12 ++++++++++
 .../DynamicReflectionDelegateFactory.cs       | 14 +++++++----
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/Src/Newtonsoft.Json.Tests/Utilities/DynamicReflectionDelegateFactoryTests.cs b/Src/Newtonsoft.Json.Tests/Utilities/DynamicReflectionDelegateFactoryTests.cs
index 3fc261d0..da447eb8 100644
--- a/Src/Newtonsoft.Json.Tests/Utilities/DynamicReflectionDelegateFactoryTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Utilities/DynamicReflectionDelegateFactoryTests.cs
@@ -193,6 +193,29 @@ namespace Newtonsoft.Json.Tests.Utilities
 
             Assert.AreEqual("Name!", (string)result);
         }
+
+        [Test]
+        public void ConstructorStruct()
+        {
+            Func<object> creator1 = DynamicReflectionDelegateFactory.Instance.CreateDefaultConstructor<object>(typeof(MyStruct));
+            MyStruct myStruct1 = (MyStruct)creator1.Invoke();
+            Assert.AreEqual(0, myStruct1.IntProperty);
+
+            Func<MyStruct> creator2 = DynamicReflectionDelegateFactory.Instance.CreateDefaultConstructor<MyStruct>(typeof(MyStruct));
+            MyStruct myStruct2 = creator2.Invoke();
+            Assert.AreEqual(0, myStruct2.IntProperty);
+        }
+    }
+
+    public struct MyStruct
+    {
+        private int _intProperty;
+
+        public int IntProperty
+        {
+            get { return _intProperty; }
+            set { _intProperty = value; }
+        }
     }
 }
 
diff --git a/Src/Newtonsoft.Json.Tests/Utilities/ExpressionReflectionDelegateFactoryTests.cs b/Src/Newtonsoft.Json.Tests/Utilities/ExpressionReflectionDelegateFactoryTests.cs
index 7888fd2c..28730208 100644
--- a/Src/Newtonsoft.Json.Tests/Utilities/ExpressionReflectionDelegateFactoryTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Utilities/ExpressionReflectionDelegateFactoryTests.cs
@@ -362,6 +362,18 @@ namespace Newtonsoft.Json.Tests.Utilities
             JsonSerializerTest.DictionaryKey key = (JsonSerializerTest.DictionaryKey)result;
             Assert.AreEqual("First!", key.Value);
         }
+
+        [Test]
+        public void ConstructorStruct()
+        {
+            Func<object> creator1 = ExpressionReflectionDelegateFactory.Instance.CreateDefaultConstructor<object>(typeof(MyStruct));
+            MyStruct myStruct1 = (MyStruct)creator1.Invoke();
+            Assert.AreEqual(0, myStruct1.IntProperty);
+
+            Func<MyStruct> creator2 = ExpressionReflectionDelegateFactory.Instance.CreateDefaultConstructor<MyStruct>(typeof(MyStruct));
+            MyStruct myStruct2 = creator2.Invoke();
+            Assert.AreEqual(0, myStruct2.IntProperty);
+        }
     }
 }
 
diff --git a/Src/Newtonsoft.Json/Utilities/DynamicReflectionDelegateFactory.cs b/Src/Newtonsoft.Json/Utilities/DynamicReflectionDelegateFactory.cs
index fdd930b5..43ee712f 100644
--- a/Src/Newtonsoft.Json/Utilities/DynamicReflectionDelegateFactory.cs
+++ b/Src/Newtonsoft.Json/Utilities/DynamicReflectionDelegateFactory.cs
@@ -208,24 +208,28 @@ namespace Newtonsoft.Json.Utilities
             dynamicMethod.InitLocals = true;
             ILGenerator generator = dynamicMethod.GetILGenerator();
 
-            GenerateCreateDefaultConstructorIL(type, generator);
+            GenerateCreateDefaultConstructorIL(type, generator, typeof(T));
 
             return (Func<T>)dynamicMethod.CreateDelegate(typeof(Func<T>));
         }
 
-        private void GenerateCreateDefaultConstructorIL(Type type, ILGenerator generator)
+        private void GenerateCreateDefaultConstructorIL(Type type, ILGenerator generator, Type delegateType)
         {
             if (type.IsValueType())
             {
                 generator.DeclareLocal(type);
                 generator.Emit(OpCodes.Ldloc_0);
-                generator.Emit(OpCodes.Box, type);
+
+                // only need to box if the delegate isn't returning the value type
+                if (type != delegateType)
+                {
+                    generator.Emit(OpCodes.Box, type);
+                }
             }
             else
             {
                 ConstructorInfo constructorInfo =
-                    type.GetConstructor(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance, null,
-                        ReflectionUtils.EmptyTypes, null);
+                    type.GetConstructor(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance, null, ReflectionUtils.EmptyTypes, null);
 
                 if (constructorInfo == null)
                 {