The desired behavior is not yet implemented. If you do not have permission to view the article it should redirect you to the login facility and offer you the opportunity to join if you are not a member. If the result of that interaction is that you are a logged in member, it should display the article.
The behavior should be exactly the same for all protected material. It will require some work on the main site to create that behavior and it may take some rearranging of the file systems.