I fixed bug 687113 for the unlock dialog, but not for the login dialog, I saw that:
- the entry only gets the disabled look, it's still sensitive
- which triggers the next bug: it's never made enabled/sensitive again

I tried to fixed the second issue, but I saw there were lots of differences in the implementation, "validation-failed", "validation-completed" unused, etc.

From bug 687112, I get:

Jasper:
"Given that the login dialog and unlock dialog use the same UI, it probably
makes sense to make it into a shared widget that does some part of the PAM
step, and has a signal for handoff (raise modal, defer to gdm)"

Giovanni:
"I might disagree with that. Yes, they look similar, but they are really very
different in the implementation and actor hierarchy, so to unify them I'm
afraid you'll get a generic monster with no actual benefit to the two
codebases."

This is a new bug to track if we do that or not, because this "blocks" bug 687113 (not really, but you get the feeling).