Major Description
In Open Liberty's "fork" of CXF, we made some changes to better handle cases where an entity is empty. IIRC (and we made this change a while back, so my memory is a little fuzzy), the TCK checks things where the entity stream is null and when the entity stream is non-null but empty - in both cases the "hasEntity" method should return false. I believe that the changes that we made affected multiple similar test cases to this one:
com/sun/ts/tests/jaxrs/ee/rs/container/requestcontext/JAXRSClient.java#hasEntityWhenNoEntityTest_from_standalone: