Unable to specify interface type to GetCustomAttributes

[mconnew]

On the full framework, WCF looks for any attributes declared on a type where the attribute type derives from IServiceBehavior. This works on the full framework, but on .Net Core an ArgumentException is thrown with the message "Type passed in must be derived from System.Attribute or System.Attribute itself." Here is a simple repro which runs to completion on the full framework but throws on .Net Core.

using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Description;

    class Program
    {
        static void Main(string[] args)
        {
            var ti = typeof(MyService).GetTypeInfo();
            var attrs = ti.GetCustomAttributes(typeof(IServiceBehavior), false);
        }

        [ServiceContract]
        public interface IMyService
        {
            [OperationContract]
            string Hello(string hello);
        }

        public class MyService : IMyService
        {
            public string Hello(string hello) { return hello; }
        }
    }

[ghost]

It looks like the desktop has a mismatch in behavior between

MemberInfo.GetCustomAttributes(attributeType, inherit)  (accepts interface on desktop)

and

CustomAttributeExtensions.GetCustomAttributes(this memberInfo, attributeType, inherit) (does NOT accept interface on desktop.)

(This is probably because CustomAttributeExtensions.GetCustomAttribute() is statically defined to return IEnumerable rather than object[], so it has to ensure everything that passes the filter is assignable to Attribute.)

On the desktop, the C# expression "ti.GetCustomAttributes()" resolves to MemberInfo.GetCustomAttributes().

On .NetCore 1.0, MemberInfo.GetCustomAttributes() doesn't exist, so the expression "ti.GetCustomAttributes()" resolves to the more restrictive CustomAttributeExtensions version.

With .NS2.0, MemberInfo.GetCustomAttributes() is returning, so this won't be such a problem.

However, as part of investigating this, I realized that corert gets MemberInfo.GetCustomAttribute() wrong so there's an issue to fix there.

[ghost]

With .NS2.0, MemberInfo.GetCustomAttributes() is returning, so this won't be such a problem.