... and the answer is no. After a longer display-sleep i woke it up to find myself back at the login prompt. Definitely that and not the lock screen.
This may in part be related to long-term issues I have with this monitor. Early-revision Dell P2715Q 4K monitors have known firmware- related issues with waking from sleep. It has phases. Sometimes it just works. Sometimes it's narcoleptic, taking the form of just going straight back to sleep after an attempted wake. And sometimes it wakes thinking it's just a 1440p monitor, and I don't notice until I get some text on the screen and think 'that doesn't look right'. That's what happened this time, and I think only happens after a longer sleep. Generally the fix in this instance is to switch the monitor off and on again, and it comes on secure in its identity as a 4K monitor. But as I switched it off, the session I'd just logged into again was again logged out. So I'm guessing Xorg/nVidia/Gnome between them are seeing a *change* in the monitor configuration attached to the computer. I would say it's still a bug that its response to that is to bug out, rather than shape itself around the new reality, but I don't know if that's just something we'll need Wayland working to deal with more gracefully. syslog covering the wake-up attached, FWIW (it's quite busy). There's one segfault in there looking similar to those I saw earlier, from the moment of trying to wake it up: Sep 29 13:59:01 fleetfoot kernel: [15526.672810] gnome-shell[26357]: segfault at 2c ip 00007fb47879d434 sp 00007ffd919279a8 error 4 in libmutter-1.so.0.0.0[7fb4786ff000+140000] However grepping for it in syslog I also see it happened twice earlier today too, while I was away from the computer: Sep 29 10:59:10 fleetfoot kernel: [ 4736.585186] gnome-shell[1892]: segfault at 2c ip 00007fb1e3549434 sp 00007fff343753c8 error 4 in libmutter-1.so.0.0.0[7fb1e34ab000+140000] Sep 29 12:26:32 fleetfoot kernel: [ 9977.733747] gnome-shell[21408]: segfault at 2c ip 00007f9d9f7be434 sp 00007ffd5a80ce88 error 4 in libmutter-1.so.0.0.0[7f9d9f720000+140000] It's possible this was triggered by the cat stepping on the keyboard or trackpad. I can also see there *wasn't* any segfault at the time I switched the monitor off and on again, and yet I was still bumped out of my gnome session. I dare suggest that even if the monitor's dodgy and even if the driver is having issues, gnome-shell should not segfault, but fail more gracefully. (Or is it libmutter that's segfaulting?) I'm going to try enabling that 'needs root rights' setting. ** Attachment added: "syslog.wakeup" https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1720149/+attachment/4958680/+files/syslog.wakeup -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1720149 Title: gnome-shell segv on wake from display or system sleep To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1720149/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
