Comment 10 for bug 1309744

I upgraded Xubuntu from 12.04 LTS to 14.04 LTS and I removed xscreensaver based on the post-upgrade recommendation.

However, what I found was that the screen blanked while parole was playing a video. Here is what is happening:

Parole executes xdg-screensaver to inhibit the screen saver while video is being played and resume normal screen saver operations when the video has either stopped or is paused.

xdg-screensaver is a shell script which detects which screen saver is installed and then proceeds to perform the requested operation on the screen saver detected - note here, that light-locker is not supported, but xscreensaver is supported.

When no known screen saver is detected, xdg-screensaver defaults to manipulating xset. Light locker is not inhibited and its own timer will expire, thereby blanking the screen.

A cursor look at light-locker-command indicates that it supports immediately locking the screen only. i.e.: There is no way for xdg-screensaver to inhibit the light locker timer using light-locker-command.

So this issue is still VERY much valid for the light-locker package and its status ought to be changed from invalid. The developers for light-locker will need to work closely with the developers of xdg-utils to get this issue resolved.

For those of you interested in a work-around: Re-install xscreensaver and let light-locker pick up the dbus messages sent from the screen saver. Alternatively, uninstall light-locker and go back to xscreensaver.

IMHO, light-locker is immature and should not have been introduced into a LTS release, but its heading into a promising direction.