NH-3911 - Fixed InvalidCastException in ReflectionOptimizer

Property and field may have different incompatible types
e.g. shadowed by a derived class to return a more specific type.
Make sure we handle this correctly.

Author: LordJZ

src/NHibernate.Test/ReflectionOptimizerTest/LcgFixture.cs

@@ -1,4 +1,5 @@
 using System;
+using NHibernate.Bytecode;
 using NHibernate.Bytecode.Lightweight;
 using NHibernate.Properties;
 using NUnit.Framework;
@@ -53,5 +54,41 @@ public void NoGetter()
 
 			Assert.Throws<PropertyNotFoundException>(() => new ReflectionOptimizer(typeof (NoGetterClass), getters, setters));
 		}
+
+		public class GetterTypeMismatchClass
+		{
+			object _property;
+
+			public string Property
+			{
+				get { return _property as string ?? "str"; }
+			}
+		}
+
+		// Property and field may have different incompatible types
+		// e.g. shadowed by a derived class to return a more specific type.
+		// Make sure we handle this correctly.
+		[Test]
+		public void TestGetterTypeMismatch()
+		{
+			var obj = new GetterTypeMismatchClass();
+			const string property = "Property";
+
+			NoSetterAccessor accessor = new NoSetterAccessor(new CamelCaseUnderscoreStrategy());
+			Assert.IsTrue(accessor.CanAccessThroughReflectionOptimizer);
+
+			ReflectionOptimizer reflectionOptimizer = new ReflectionOptimizer(
+				obj.GetType(),
+				new[] { accessor.GetGetter(obj.GetType(), property) },
+				new[] { accessor.GetSetter(obj.GetType(), property) });
+
+			IAccessOptimizer accessOptimizer = reflectionOptimizer.AccessOptimizer;
+
+			accessOptimizer.SetPropertyValues(obj, new object[] { 10 });
+			object[] values = accessOptimizer.GetPropertyValues(obj);
+
+			Assert.AreEqual("str", values[0]);
+		}
+
 	}
 }

src/NHibernate/Bytecode/Lightweight/ReflectionOptimizer.cs

@@ -41,7 +41,7 @@ public ReflectionOptimizer(System.Type mappedType, IGetter[] getters, ISetter[]
 			//this.setters = setters;
 
 			GetPropertyValuesInvoker getInvoker = GenerateGetPropertyValuesMethod(getters);
-			SetPropertyValuesInvoker setInvoker = GenerateSetPropertyValuesMethod(getters, setters);
+			SetPropertyValuesInvoker setInvoker = GenerateSetPropertyValuesMethod(setters);
 
 			accessOptimizer = new AccessOptimizer(getInvoker, setInvoker, getters, setters);
 
@@ -186,7 +186,7 @@ private GetPropertyValuesInvoker GenerateGetPropertyValuesMethod(IGetter[] gette
 		/// Generates a dynamic method on the given type.
 		/// </summary>
 		/// <returns></returns>
-		private SetPropertyValuesInvoker GenerateSetPropertyValuesMethod(IGetter[] getters, ISetter[] setters)
+		private SetPropertyValuesInvoker GenerateSetPropertyValuesMethod(ISetter[] setters)
 		{
 			var methodArguments = new[] {typeof (object), typeof (object[]), typeof (SetterCallback)};
 			DynamicMethod method = CreateDynamicMethod(null, methodArguments);
@@ -203,7 +203,6 @@ private SetPropertyValuesInvoker GenerateSetPropertyValuesMethod(IGetter[] gette
 			{
 				// get the member accessor
 				ISetter setter = setters[i];
-				System.Type valueType = getters[i].ReturnType;
 
 				var optimizableSetter = setter as IOptimizableSetter;
 
@@ -217,7 +216,7 @@ private SetPropertyValuesInvoker GenerateSetPropertyValuesMethod(IGetter[] gette
 					il.Emit(OpCodes.Ldc_I4, i);
 					il.Emit(OpCodes.Ldelem_Ref);
 
-					EmitUtil.PreparePropertyForSet(il, valueType);
+					EmitUtil.PreparePropertyForSet(il, optimizableSetter.Type);
 
 					// using the setter's emitted IL
 					optimizableSetter.Emit(il);

src/NHibernate/Properties/BasicPropertyAccessor.cs

@@ -346,6 +346,11 @@ public MethodInfo Method
 				get { return property.GetSetMethod(true); }
 			}
 
+			public System.Type Type
+			{
+				get { return property.PropertyType; }
+			}
+
 			#endregion
 
 			public void Emit(ILGenerator il)

src/NHibernate/Properties/FieldAccessor.cs

@@ -320,6 +320,11 @@ public MethodInfo Method
 				get { return null; }
 			}
 
+			public System.Type Type
+			{
+				get { return field.FieldType; }
+			}
+
 			#endregion
 
 			public void Emit(ILGenerator il)

src/NHibernate/Properties/IOptimizableSetter.cs

@@ -8,6 +8,12 @@ namespace NHibernate.Properties
 	/// </summary>
 	public interface IOptimizableSetter
 	{
+		/// <summary>
+		/// When implemented by a class, gets the <see cref="System.Type"/> of the Property/Field.
+		/// </summary>
+		/// <value>The <see cref="System.Type"/> of the Property/Field.</value>
+		System.Type Type { get; }
+
 		/// <summary>
 		/// Emit IL to set the property of an object to the value. The object
 		/// is loaded onto the stack first, then the value, then this method