Description of problem:
Platform BZ for https://issues.jboss.org/browse/SWITCHYARD-2155

REST Binding always returns 204 (No Content) for void REST methods even when SwitchYard application throws an exception. Note that a bare RESTEasy app without SY behaves differently, i.e. it returns 204 for void methods only when the REST method returns successfully and instead returns 500 when it throws an error.

I'm attaching a simple reproducer project. Say I have a following REST interface:

@Path("/")
public interface SampleResource {
    @GET
    @Path("/ok")
    void ok();

    @GET
    @Path("/error")
    void error();
}

and have the following Bean service:

@Service(SampleService.class)
public class SampleServiceBean implements SampleService {
    @Override
    public void ok() {
        System.out.println("ok");
    }
    @Override
    public void error() {
        System.out.println("error");
        throw new RuntimeException();
    }
}

Running the Client.java, you will get the following result.

http://localhost:8080/sample/ok    => 204
http://localhost:8080/sample/error => 204

However, what I expect is getting some error (such as 500) for the latter request instead of getting 204.