caffeine doesn't work on additional screen in xubuntu 16.04

[Mac Damien]

Hi,

I used caffeine since a while, but the last version doesn't work with my second screen.
Here is my case :
1) I launch caffeine in a terminal
2) I watch a video with vlc in fullscreen on my principal screen
    => I see messages "INFO:root:caffeine is inhibiting desktop idleness" and then "INFO:root:caffeine is no longer inhibiting desktop idleness" a short time after I quit fullscreen from vlc
3) I put vlc on my second display, and put it in fullscreen
    => I see no message, and after some time my screensaver activates

My current version of caffeine is 2.8.3-3build1, and I'm with Xubuntu 16.04.

I'm pretty sure it was working before (perhaps many months ago), as I remember regarding long videos on my second screen without getting disturbed by screensaver, but I can't find an update date where caffeine has been updated.
Or perhaps the problem comes from another package update ?

I hope this details will help you reproducing and finding the problem.

Cheers,
Damien

[Reuben Thomas (rrt)]

Interesting! I run caffeine 2.9.4 (please install this from the PPA before going any further) on my Ubuntu GNOME 16.04 two-screen system without problems.

What happens when you use xdg-screensaver directly?

Try running, in a terminal:

window_id=`xwininfo | grep "Window id" | cut -d " " -f 4`

Now click on the terminal window, and then run:

xdg-screensaver suspend $window_id
xdg-screensaver resume $window_id

This performs the same steps at a lower level as turning Caffeine on then off again manually. If this gives the same problem as using Caffeine, then the bug is definitely not in Caffeine.

[Mac Damien (lemacounet)]

I tested your commands, and it doesn't deactivate screensaver (I've got an error).

But strange thing, I tested caffeine again and it works (same version), on both screens ! :-)
I'm sure it wasn't working like that when I submitted the bug report. Perhaps it works well after a fresh reboot, but something can breaks it ?

Do you have some commands I could run to get more informations if the problem comes again ? And/or do you prefer closing the bug report ?

Thanks for your answer

[Reuben Thomas (rrt)]

Thanks for getting back to me.

It's certainly possible it could stop working. I don't have any other information to give; but if it stops working again, and xdg-screensaver doesn't work, then the bug is not in Caffeine, so start by reporting a bug in xdg-screensaver.

I'll close the bug.