Add missing equality checks to MethodSignatureComparer.EqualSignatureTypes

Author: stakx

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Castle Core Changelog
 
+## Unreleased
+
+Bugfixes:
+- Add missing equality checks in `MethodSignatureComparer.EqualSignatureTypes` to fix `TypeLoadException`s ("Method does not have an implementation") (@stakx, #310)
+
 ## 4.2.0 (2017-09-28)
 
 Enhancements:

src/Castle.Core.Tests/DynamicProxy.Tests/ExplicitInterfaceTestCase.cs

@@ -176,6 +176,13 @@ public void NonVirtualExplicitInterfaceMethods_AreIgnored_OnClassProxy()
 
 			Assert.AreEqual(5, result);
 		}
+
+		[Test]
+		public void CreateClassProxy_GivenAdditionalInterfaceWithOverloadedGenericMethodsHavingGenericParameter_SuccessfullyCreatesProxyInstance()
+		{
+			var instance = generator.CreateClassProxy(typeof(object), new Type[] { typeof(InterfaceWithOverloadedGenericMethod) }, interceptor);
+			Assert.NotNull(instance);
+		}
 	}
 
 	public class ExplicitInterfaceWithPropertyImplementation : ISimpleInterfaceWithProperty
@@ -185,4 +192,18 @@ public int Age
 			get { throw new NotImplementedException(); }
 		}
 	}
+
+	public interface InterfaceWithOverloadedGenericMethod
+	{
+		void GenericMethod<T>(GenericClass1<T> arg);
+		void GenericMethod<T>(GenericClass2<T> arg);
+	}
+
+	public class GenericClass1<T>
+	{
+	}
+
+	public class GenericClass2<T>
+	{
+	}
 }

src/Castle.Core.Tests/MethodComparerTestCase.cs

@@ -355,5 +355,28 @@ public void Compare_inherited_double_nested_return_method()
 			Assert.IsTrue(mc.Equals(typeof(Base).GetMethod("GenericMethod7"),
 				typeof(Inherited).GetMethod("GenericMethod7")));
 		}
+
+		[Test]
+		public void Compare_two_method_overloads_with_generic_arg_types()
+		{
+			var mc = MethodSignatureComparer.Instance;
+			var methods = typeof(IHaveOverloadedGenericMethod).GetMethods();
+			var firstOverload = methods[0];
+			var secondOverload = methods[1];
+
+			// The overloads must obviously have different signatures, or we could never even have
+			// compiled this test code successfully. The arguments must have a different type:
+			Assert.IsFalse(mc.Equals(firstOverload, secondOverload));
+		}
+
+		private interface IHaveOverloadedGenericMethod
+		{
+			void GenericMethod<T>(GenericClass1<T> arg);
+			void GenericMethod<T>(GenericClass2<T> arg);
+		}
+
+		private class GenericClass1<T> { }
+
+		private class GenericClass2<T> { }
 	}
 }

src/Castle.Core/DynamicProxy/Generators/MethodSignatureComparer.cs

@@ -79,20 +79,35 @@ public bool EqualParameters(MethodInfo x, MethodInfo y)
 
 		public bool EqualSignatureTypes(Type x, Type y)
 		{
-			if (x.GetTypeInfo().IsGenericParameter != y.GetTypeInfo().IsGenericParameter)
+			var xti = x.GetTypeInfo();
+			var yti = y.GetTypeInfo();
+
+			if (xti.IsGenericParameter != yti.IsGenericParameter)
+			{
+				return false;
+			}
+			else if (xti.IsGenericType != yti.IsGenericType)
 			{
 				return false;
 			}
 
-			if (x.GetTypeInfo().IsGenericParameter)
+			if (xti.IsGenericParameter)
 			{
-				if (x.GetTypeInfo().GenericParameterPosition != y.GetTypeInfo().GenericParameterPosition)
+				if (xti.GenericParameterPosition != yti.GenericParameterPosition)
 				{
 					return false;
 				}
 			}
-			else if (x.GetTypeInfo().IsGenericType)
+			else if (xti.IsGenericType)
 			{
+				var xGenericTypeDef = xti.GetGenericTypeDefinition();
+				var yGenericTypeDef = yti.GetGenericTypeDefinition();
+
+				if (xGenericTypeDef != yGenericTypeDef)
+				{
+					return false;
+				}
+
 				var xArgs = x.GetGenericArguments();
 				var yArgs = y.GetGenericArguments();