Hello,
lightdm stores the last session and language of a user in /var/lib/AccountsService/users/$USER and ${HOME}/.dmrc (actually, the language is not stored in .dmrc unless the accounts-daemon is not running, see LP bug #1068853) such that the last session and language can be restored once a user logs in again.
However, when using lightdm-gtk-greeter, there's is no way to load the last session as the session selector always remains at the selection of the last user logged in, thus ignoring what's been stored through AccountsService or .dmrc. On the other hand, when using unity-greeter, it's never possible to set the login language (what many people need in a multi-user environment).
When enabling the language selector for lightdm-gtk-greeter, the language selector is always set to an empty value which means that the last selection is actually restored per user. However, this is not the case for the session, there is no empty selection. Thus, there is an inconsistency between restoring the last session and the last language. The latter is restored per user while the former is just kept at the selection of the last user who logged in through lightdm.
It is therefore highly desirable to have the options "last session" and "last language selection" in lightdm (like it was the case for gdm 2.20) and both last session and the last selection should be default allowing the user to log in with their default settings of choice, having to make these selections only once.
Cheers,
Adrian
