Do not reject contract from the same method, could happen by a type with...

Do not reject contract from the same method, could happen by a type with multiple service contracts within the typie hierarchy.

For details, see: http://lists.ximian.com/pipermail/mono-devel-list/2010-September/035940.html

mcs/class/System.ServiceModel/System.ServiceModel.Description/ContractDescriptionGenerator.cs

@@ -255,8 +255,8 @@ namespace System.ServiceModel.Description
 				}
 				cd.Operations.Add (od);
 			}
-			else if (oca.AsyncPattern && od.BeginMethod != null ||
-				 !oca.AsyncPattern && od.SyncMethod != null)
+			else if (oca.AsyncPattern && od.BeginMethod != null && od.BeginMethod != mi ||
+				 !oca.AsyncPattern && od.SyncMethod != null && od.SyncMethod != mi)
 				throw new InvalidOperationException (String.Format ("contract '{1}' cannot have two operations for '{0}' that have the identical names and different set of parameters.", name, cd.Name));
 
 			if (oca.AsyncPattern)

mcs/class/System.ServiceModel/Test/System.ServiceModel.Description/ContractDescriptionTest.cs

@@ -420,6 +420,14 @@ namespace MonoTests.System.ServiceModel.Description
 			Assert.AreEqual (typeof (IFoo3), cd.ContractType, "#3");
 			Assert.AreEqual (3, cd.Operations.Count, "#4");
 		}
+		
+		[Test]
+		public static void MultipleContractsInTypeHierarchy ()
+		{
+			ContractDescription.GetContract (typeof (DuplicateCheckClassWrapper.ServiceInterface));
+
+			var host = new ServiceHost (typeof (DuplicateCheckClassWrapper.DummyService)); // fine in MS, fails in Mono with "A contract cannot have two operations that have the identical names and different set of parameters"
+		}
 
 		// It is for testing attribute search in interfaces.
 		public class Foo : IFoo
@@ -628,5 +636,33 @@ namespace MonoTests.System.ServiceModel.Description
 				set { foo = value; }
 			}
 		}
+
+		public class DuplicateCheckClassWrapper
+		{
+
+			[ServiceContract]
+			internal interface ServiceInterface : Foo
+			{
+			}
+
+			[ServiceContract]
+			internal interface Foo : Bar
+			{
+				[OperationContract] void Foo();
+			}
+
+			[ServiceContract]
+			internal interface Bar
+			{
+				[OperationContract] void FooBar();
+			}
+
+			internal class DummyService : ServiceInterface
+			{
+				public void FooBar() { }
+
+				public void Foo() { }
+			}
+		}
 	}
 }