Comment 5 for bug 1790110

just tested & have this issue in 19.04 (LXQt desktop & vlc)
in `vlc` i had 'disable screensaver' ticked, but xscreensaver still hid vlc (both when vlc was playing in a window, or was fullscreen)

due to [a requested] test earlier today i was using an old version of xscreensaver when I first tried, ie.

xscreensaver:
  Installed: 5.36-1ubuntu1
 *** 5.36-1ubuntu1 500
        500 http://old-releases.ubuntu.com/ubuntu zesty/universe amd64 Packages

i then closed vlc, and upgraded to the standard disco (19.04) version of xscreensaver. i restarted the xscreensaver daemon & re-tested, again vlc was overwritten [on display] by xscreensaver

// following [trimmed] output was after xscreensaver was back to 19.04's default version
guiverc@d960-ubu2:~$ apt-cache policy vlc xscreensaver
vlc:
  Installed: 3.0.6-1
 *** 3.0.6-1 500
        500 http://ftp.iinet.net.au/pub/ubuntu disco/universe amd64 Packages
xscreensaver:
  Installed: 5.42+dfsg1-1ubuntu1
 *** 5.42+dfsg1-1ubuntu1 500
        500 http://ftp.iinet.net.au/pub/ubuntu disco/universe amd64 Packages