Redirect to current page after login with link in menu

I have figured out how to show and hide links based on if the user is logged in or logged out. I have an Edit Profile link and a Logout link.
Now, I am trying to add a Login link. I can add the link to the menu, but I cannot figure out how to make it redirect the user back to the page they were on before they logged in.

For example: Bob clicks the Login link on page A.
Bob logs in.
Bob is returned to page A instead of the WordPress Dashboard.

You cannot add PHP to the menu, so I am lost. Unless there is a way to write a function and include that menu link class?

Thanks for the help.