Improvements to xflock4

[Jarno Suni]

Even if the proposed xflock4 is supposed to return non-zero exit code, if it fails, it may fail to lock even if it returns zero. For example, if xautolock is running, but it has been started with -nowlocker argument that fails to lock screen, xflock4 still returns zero. So if a user has installed and started xautolock, he/she should know what he/she is doing.

Anyway, xflock4 may return error e.g. in case it can't find a supported locker, which can happen e.g. if a screen saver daemon has crashed. (A daemon could be started in the script, if that is desirable, but it requires adding that feature to the script.)

To be able to act according to the exit code of xflock4, caller of xflock4 should check it. Especially, when xfce4-session-logout or xfce4-power-manager call xflock4 before suspending, they should notify user, that locking fails, and let user cancel suspending.

A related bug report: https://bugzilla.xfce.org/show_bug.cgi?id=6413


-- 
Jarno Suni - http://iki.fi/8/