Spawn screenlocker again when it died doesn't work with lxqt-leave --lockscreen

[stefonarch]

Rarely the screenlocker can die, it happened only once here months ago with Hyprland, but 4 times in the last 2 days, with both swaylock and hyprlock.

In niri shortcuts can be allowed also when screen is locked (audio volume for example when playing music):
Mod+Shift+Q allow-when-locked=true {spawn "lxqt-leave" "--lockscreen"; }

This shortcut works perfectly when screen is unlocked, but when it's locked and the locker is killed from another tty it doesn't, while setting it directly like Mod+Shift+Q allow-when-locked=true {spawn "hyprlock"; } it works fine - the lock screen reappears and unlock is possible.

The locker can also be activated from another tty with
WAYLAND_DISPLAY=wayland-1 hyprlock (actually any locker, it hasn't to be same). When doing that after trying to do it with the shortcut 2 dialogs like below are shown:

When clicking "ok" a 3rd one appears, after clicking ok on all lxqt-leave dumps core.
The formula is "one shortcut press 1 dialog +1", e.g. 3 times shortcut press 4 dialogs, closing one opens another one but at some point all are closed and the coredump happens. It's hard to describe.

#0  0x00007cff2cdd33e0 in ??? () at /usr/lib/libQt6Core.so.6
#1  0x00007cff2cdd37ef in ??? () at /usr/lib/libQt6Core.so.6
#2  0x00007cff2cf87a57 in ??? () at /usr/lib/libQt6Core.so.6
#3  0x00007cff2cf8fefe in QProcess::waitForFinished(int) () at /usr/lib/libQt6Core.so.6
#4  0x00007cff2ccc23f7 in ??? () at /usr/lib/libQt6Core.so.6
#5  0x00007cff2cf903e5 in QProcess::~QProcess() () at /usr/lib/libQt6Core.so.6
#6  0x00007cff2cdb8fe2 in QObjectPrivate::deleteChildren() () at /usr/lib/libQt6Core.so.6
#7  0x00007cff2cdbfc19 in QObject::~QObject() () at /usr/lib/libQt6Core.so.6
#8  0x00005c0d5081f8db in ??? ()
#9  0x00007cff2c6376b5 in ??? () at /usr/lib/libc.so.6
#10 0x00007cff2c637769 in __libc_start_main () at /usr/lib/libc.so.6
#11 0x00005c0d5081f9a5 in ??? ()

Again: the shortcut works normally usually. I don't remember if also other compositors allow shortcuts when locked, needs testing and the shortcut should also work in the rare cases when the locker dies.

[stefonarch]

Just tested in Hyprland where locked can be added as flag too to the keybind, but doesn't work too.

[tsujan]

I doubt that anything can be done by LXQt. liblxqt can just call the locker command on Wayland.

[stefonarch]

I noticed I don't have to crash the screenlocker, I can repeat the keybind. This is what I found after unlocking when I used 4 times the shortcut (the first will lock):

screenrec-1754126660.mp4

We should check if it's running (we find the screenlocker used in session.conf ? This usually doesn't happen because the compositor inhibits any keybind. But as it can be useful in the rare situation with a locker crashed we should fix it.