suspend with screen lock does not work

Commit 32f76126 ("screensaver: Run lock command synchronously (Fixes #70 (closed))") broke suspending with a screen locker.

• in Settings Power Manager check 'Lock screen when system is going to sleep' (xfconf-query -c xfce4-session -p /shutdown/LockScreen should show true)
• run xfce4-session-logout -s (or click 'Suspend' from taskbar button)
• what used to happen: machine is suspended. On resume, screen locker is running.
• what happens now: machine is not suspended, but screen locker runs! After entering password and unlocking the screen locker, now the machine suspends.

The problem is xfce4-session calls xfce_screensaver_lock before suspending (in xfsm_systemd_lock_screen). If xfce_screensaver_lock blocks, then the suspend is delayed until after the screensaver is unlocked.

mentioned in issue xfce4-session#214 (closed)

changed title from suspend button does not work to suspend and lock screen does not work

changed the description

changed title from suspend and lock screen does not work to suspend with screen lock does not work

Yes, but as said in xfce4-session#214 (comment 102657), this is the expected behavior. You can't be synchronous and asynchronous at the same time, you have to choose. And it's necessary to be synchronous to fix #70 (closed) as much as possible: let screensavers lock the session and give back the hand if that's how they work, and only then suspend.

In the case of a screensaver that doesn't hand over, there's no choice but to make the lock command asynchronous yourself, using sh -c 'lock-command & [sleep n]' instead of lock-command. I'm closing, there's nothing more we can do here.

closed

added 3. Not a Bug label

added 5. Screensaver label

In the case of a screensaver that doesn't hand over, there's no choice but to make the lock command asynchronous yourself,

But if the user sets an asynchronous lock command, then they will hit bug xfce4-session#214 (closed) when running xflock4 (i.e. with an asynchronous lock command, xflock4 will always return immediately instead of blocking).

If xfce4-session calling xfce_screensaver_lock now requires the user's locker process to be run asynchronously, then it would be better for this to be enforced by forking before executing the user locker. Otherwise, this change breaks backwards compatibility with all existing setups that have a synchronous lock command already set.

We don't have to be backward-compatible with commands based on buggy behavior. Making the lock() call synchronous fixes #70 (closed), which you apparently want to ignore, but I don't. This bug has a history, and its fix was pushed for a reason: most screensavers work like this, especially xfce4-screensaver.

xfce4-session#214 (closed) was not a bug by itself. The only bug was xflock4 exiting in timeout error instead of blocking as it should, now that's fixed. It's up to you to adapt the command you pass to xflock4 so that its execution is compatible with the way lock+suspend works.