Bug 443003

Summary: Plasma Crashes in QQuickWindowPrivate::pointerEventInstance() on Wayland when using OpenTabletDriver
Product: [Plasma] plasmashell Reporter: C0D3 M4513R <while.stuck+kde>
Component: generic-crashAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: crash CC: nate, plasma-bugs-null, while.stuck+kde
Priority: NOR Keywords: drkonqi, wayland-only
Version First Reported In: 5.22.5   
Target Milestone: 1.0   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: New crash information added by DrKonqi

Description C0D3 M4513R 2021-09-27 09:33:59 UTC 
Application: plasmashell (5.22.5)

Qt Version: 5.15.2
Frameworks Version: 5.86.0
Operating System: Linux 5.14.7-arch1-1 x86_64
Windowing System: Wayland
Drkonqi Version: 5.22.5
Distribution: "Arch Linux"

-- Information about the crash:
- What I was doing when the application crashed:

I was using my tablet (Wacom MTE-450). I uninstalled the Wacom drivers, and am using OpenTabletDriver instead. OpenTabletDriver is superior in many ways, imo.

OTD=OpenTabletDriver

- Unusual behavior I noticed:

The cursor was radpidly changing shapes. It almost looked, as if the cursor was selecting stuff, and changing to a normal cursor rapidly or having the normal cursor mode active st the same time.

There existed a bug in OTD, where it would click under specific condutions, without the user actually clicking. Afaik I am still using a version, where that bug is still there.

OTD has access to the raw tablet input devices (custum udev rules give tablets input devices a chmod of 0666), and maps the tablet input to absolute onscreen mouse coordinates.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault

[KCrash Handler]
#4  0x00007fcba5ccd25e in QQuickWindowPrivate::pointerEventInstance(QEvent*) const () at /usr/lib/libQt5Quick.so.5
#5  0x00007fcba5cd699b in QQuickWindow::tabletEvent(QTabletEvent*) () at /usr/lib/libQt5Quick.so.5
#6  0x00007fcba465c625 in QWindow::event(QEvent*) () at /usr/lib/libQt5Gui.so.5
#7  0x00007fcba4f56d62 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#8  0x00007fcba42773ba in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#9  0x00007fcba4650de9 in QGuiApplicationPrivate::processTabletEvent(QWindowSystemInterfacePrivate::TabletEvent*) () at /usr/lib/libQt5Gui.so.5
#10 0x00007fcba46257e5 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Gui.so.5
#11 0x00007fcba1e29101 in  () at /usr/lib/libQt5WaylandClient.so.5
#12 0x00007fcba257a4dc in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#13 0x00007fcba25ce749 in  () at /usr/lib/libglib-2.0.so.0
#14 0x00007fcba2577bc1 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#15 0x00007fcba42cffe6 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#16 0x00007fcba4275d2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#17 0x00007fcba427e294 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#18 0x0000555acf70221a in  ()
#19 0x00007fcba3c01b25 in __libc_start_main () at /usr/lib/libc.so.6
#20 0x0000555acf70234e in  ()
[Inferior 1 (process 24950) detached]

Possible duplicates by query: bug 442803, bug 442154, bug 440124, bug 439941, bug 439875.

Reported using DrKonqi
Comment 1 C0D3 M4513R 2021-09-27 09:36:03 UTC 
Created attachment 141945 [details]
New crash information added by DrKonqi

plasmashell (5.22.5) using Qt 5.15.2

This is another crash report. Same situation. Same outcome. Plasma Desktop crashed in about a minute.

-- Backtrace (Reduced):
#4  0x00007fcba5ccd25e in QQuickWindowPrivate::pointerEventInstance(QEvent*) const () at /usr/lib/libQt5Quick.so.5
#5  0x00007fcba5cd699b in QQuickWindow::tabletEvent(QTabletEvent*) () at /usr/lib/libQt5Quick.so.5
#6  0x00007fcba465c625 in QWindow::event(QEvent*) () at /usr/lib/libQt5Gui.so.5
#7  0x00007fcba4f56d62 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#8  0x00007fcba42773ba in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
Comment 2 C0D3 M4513R 2021-09-27 09:47:32 UTC 
Before completely crashing the desktop goes black, for a little while, before then completely crashing, and not recovering.
By manually starting plasmashell, the black desktop and missing taskbar can be restored.

OTD source here:
https://github.com/OpenTabletDriver/OpenTabletDriver
Comment 3 Nate Graham 2024-02-22 20:51:25 UTC 
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with either Plasma 5.27 (the current LTS version) or Plasma 6.0 (to be released in one week)? Thanks a lot!
Comment 4 C0D3 M4513R 2024-03-04 15:10:07 UTC 
Unfortunately I wiped that arch system in favor for NixOS(23.11) and I cannot re-test this anytime soon, as I need to focus on other things.
I'm still running KDE, just on X11.
I don't know when I can test wayland again or when I'll get to testing it again. 
(tbh, I don't even know how to switch from x11 to wayland in nixos right now and don't care to find out at this time, as I have enough to do right now)
Comment 5 Bug Janitor Service 2024-03-19 03:46:16 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 6 C0D3 M4513R 2024-03-19 12:48:15 UTC 
I probably won't get to testing this in within 30 days.
So here you go bot.