Bug 1226392

Summary: lxqt-config-monitor crashes with kscreen on login, wakeup, launch
Product: [openSUSE] openSUSE Tumbleweed Reporter: Brandon Bigam <brbigam>
Component: LXQtAssignee: lxqt-bugs <lxqt-bugs>
Status: NEW --- QA Contact: E-mail List <qa-bugs>
Severity: Normal    
Priority: P5 - None    
Version: Current   
Target Milestone: ---   
Hardware: x86-64   
OS: openSUSE Tumbleweed   
Whiteboard:
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description Brandon Bigam 2024-06-15 18:40:00 UTC 
lxqt-config-monitor crashes on every login, every wake from sleep, and every user launch of the settings module. It segfaults and coredumps, with kscreen.

Steps to Reproduce
    Log in to an LXQt session, or wake from sleep within one (not just from screen lock)
    OR open l-c-monitor
    Check journalctl and look in /var/lib/systemd/coredump/ folder
    See the coredump and sefault reports from those times

Expected Behavior
l-c-monitor doesn't crash and coredump in any standard usage. If kscreen crashes, l-c-monitor errors rather than crashing and coredumping.

Current Behavior
I don't have any particular need for l-c-monitor, since I use only one monitor, my laptop display. But opening it shows a window that's blank as if there's no detected display, and when I close it, it and kscreen segfault and coredump. If I check journalctl, it shows similar segfaults and coredumps for l-c-monitor on my user session login or wake from sleep, and the coredumps pile up in /var/lib/systemd/coredump/

Since there's no user-facing option to disable l-c-monitor, the coredumps just keep piling up.

System Information

    Distribution & Version: openSUSE Tumbleweed 20240612
    Kernel: 6.9.3
    Qt Version: 6.7.1
    liblxqt Version: 2.0.0
    lxqt-build-tools Version: not installed
    Package version: lxqt-config 2.0.0; libkf6screen8 6.0.5
    Openbox

Other info:
I wish there was a UI option to disable l-c-monitor.
This bug has also been filed upstream: https://github.com/lxqt/lxqt-config/issues/1004
Comment 1 Brandon Bigam 2024-06-15 18:41:54 UTC 
Backtrace using coredumpctl gdb lxqt-config-mon - where

#0 0x00007fedb9430930 in KScreen::Config::outputs() const () from /lib64/libKF6Screen.so.8
#1 0x000056150392127b in applySettings (config=..., monitors=...) at /usr/include/qt6/QtCore/qsharedpointer_impl.h:274
#2 0x0000561503923135 in LoadSettings::applyBestSettings()::{lambda(KScreen::ConfigOperation*)#1}::operator()(KScreen::ConfigOperation*) const () at /usr/src/debug/lxqt-config-2.0.0/lxqt-config-monitor/loadsettings.cpp:72
#3 0x00007fedb79e8130 in ?? () from /lib64/libQt6Core.so.6
#4 0x00007fedb943775f in KScreen::ConfigOperation::finished(KScreen::ConfigOperation*) () from /lib64/libKF6Screen.so.8
#5 0x00007fedb9437840 in ?? () from /lib64/libKF6Screen.so.8
#6 0x00007fedb79d1fbb in QObject::event(QEvent*) () from /lib64/libQt6Core.so.6
#7 0x00007fedb798ee20 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib64/libQt6Core.so.6
#8 0x00007fedb798f180 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt6Core.so.6
#9 0x00007fedb7bc2973 in ?? () from /lib64/libQt6Core.so.6
#10 0x00007fedb7712740 in ?? () from /lib64/libglib-2.0.so.0
#11 0x00007fedb7714388 in ?? () from /lib64/libglib-2.0.so.0
#12 0x00007fedb7714a3c in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#13 0x00007fedb7bc147c in QEventDispatcherGlib::processEvents(QFlagsQEventLoop::ProcessEventsFlag) ()
from /lib64/libQt6Core.so.6
#14 0x00007fedb799959b in QEventLoop::exec(QFlagsQEventLoop::ProcessEventsFlag) () from /lib64/libQt6Core.so.6
#15 0x00007fedb7992da6 in QCoreApplication::exec() () from /lib64/libQt6Core.so.6
#16 0x000056150390ec10 in main (argc=, argv=)
at /usr/src/debug/lxqt-config-2.0.0/lxqt-config-monitor/main.cpp:48