mate-settings-daemon should be compatible with light-locker

[N0rbert]

Background:
some users (as from https://askubuntu.com/q/1263287/66509 ) do not want to use mate-screensaver, but want to use light-locker instead.

Expected behaviour

• light-locker is executed, screen is locked

Actual behaviour

• error window is shown with the following text:

"
Couldn't execute command: xscreensaver-command -lock
Verify that this is a valid command.
"

This happens because of the fact that mate-settings-daemon does not know anything about light-locker.

Steps to reproduce the behaviour

1. Remove MATE ScreenSaver with

sudo apt-get purge mate-screensaver
sudo apt-get autoremove --purge

2. Install LightDM based screenlocker install the corresponding package with:

sudo apt-get install light-locker

3. Press <Ctrl>+<Alt>+<L> to test light-locker functionality

Workaround

Use some kind of hack:

cat <<EOF | sudo tee /usr/local/bin/xscreensaver-command
#!/bin/bash
light-locker-command -l
EOF
sudo chmod a+x /usr/local/bin/xscreensaver-command

to introduce the missed xscreensaver-command command.

MATE general version

1.24.0

Package version

1.24.0-1

Linux Distribution

Ubuntu MATE 20.04 LTS

Link to downstream report of your Distribution

https://pad.lv/1889632