Since hardcoded lists always suck, I'm therefore proposing that all packages containing a login manager include a special Provides: that we can query on. Then nobody ever has to come asking for a change again, and if package names change, it's fine.
After looking at everyone's suggestions and thinking a bit on my own, I think any of the following are acceptable to me:
Provides: login(graphical)
Provides: config(graphical-login)
Provides: service(graphical-login)
I like making it clear that this is a graphical login, since I'd hate for the "login" program to provide this as well. service() makes some sense since gdm - at least - continues to run after you've logged in. That's kind of service-like.
Besides that, I don't care. Any opinions? If we can arrive at some consensus, I'll start filing bugs against packages to get this set up.
- Chris