Bug 373423

Summary:	Plasma crashes when disconnecting laptop from dockingstation
Product:	[Plasma] plasmashell	Reporter:	Stefan Kaerst <stefan.kaerst>
Component:	general	Assignee:	David Edmundson <kde>
Status:	RESOLVED UPSTREAM
Severity:	crash	CC:	bshah, plasma-bugs-null, post
Priority:	NOR	Keywords:	drkonqi
Version First Reported In:	5.5.5
Target Milestone:	1.0
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Stefan Kaerst 2016-12-08 13:13:26 UTC

Application: plasmashell (5.5.5)

Qt Version: 5.5.1
Operating System: Linux 4.1.34-33-default x86_64
Distribution: "openSUSE Leap 42.1 (x86_64)"

-- Information about the crash:
- What I was doing when the application crashed:
my Lenovo Thinkpad T430 uses two secondary monitors. one via HDMI and one via DVI. Desktop is spread across all monitors. If I undock my laptop to use it offline, KDE crashes.

2nd problem: the KDE/window manager(?) is not able to view my desktop anymore. It does not matter what I do. It's like I have to attach at least one seconday monitor to see a desktop, otherwise after KDM login the screen is unusable. even a reboot with no external monitor attached solves this. this is really annoying. I have to switch to icewm to log in to X when the laptop is not on it's docking station.

openSUSE Leap 42.1 
KDE Frameworks 5.21.0
Qt 5.5.1 (built against 5.5.1)
The xcb windowing system

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Aborted
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff085e7d7c0 (LWP 16743))]

Thread 8 (Thread 0x7fefbcad3700 (LWP 17027)):
#0  0x00007ff07ba698e9 in g_main_context_check () at /usr/lib64/libglib-2.0.so.0
#1  0x00007ff07ba69df8 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff07fcb9d8b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07fa8261a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fefbe11fcf7 in KCupsConnection::run() () at /usr/lib64/libkcupslib.so
#7  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#8  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 7 (Thread 0x7ff051790700 (LWP 16844)):
#0  0x00007ff07f38cbfd in poll () at /lib64/libc.so.6
#1  0x00007ff07ba69e64 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff07fcb9d8b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07fa8261a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007ff083932282 in  () at /usr/lib64/libQt5Quick.so.5
#7  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#8  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 6 (Thread 0x7ff053fff700 (LWP 16820)):
#0  0x00007ff07eb9a03f in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ff08556586b in  () at /usr/lib64/libQt5Script.so.5
#2  0x00007ff085565899 in  () at /usr/lib64/libQt5Script.so.5
#3  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#4  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7ff059d37700 (LWP 16794)):
#0  0x00007ff07f38cbfd in poll () at /lib64/libc.so.6
#1  0x00007ff07ba69e64 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff07fcb9d8b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07fa8261a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007ff082d96e18 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#8  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7ff05b4ea700 (LWP 16791)):
#0  0x00007ff07f38cbfd in poll () at /lib64/libc.so.6
#1  0x00007ff07ba69e64 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff07fcb9d8b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07fa8261a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007ff082d96e18 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#8  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7ff06ca67700 (LWP 16751)):
#0  0x00007ff07baabcf9 in g_mutex_lock () at /usr/lib64/libglib-2.0.so.0
#1  0x00007ff07ba694b9 in g_main_context_prepare () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff07ba69d80 in  () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#4  0x00007ff07fcb9d8b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#6  0x00007ff07fa8261a in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#7  0x00007ff082d96e18 in  () at /usr/lib64/libQt5Qml.so.5
#8  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#9  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#10 0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7ff06f8af700 (LWP 16746)):
#0  0x00007ff07f38cbfd in poll () at /lib64/libc.so.6
#1  0x00007ff0842e0422 in  () at /usr/lib64/libxcb.so.1
#2  0x00007ff0842e200f in xcb_wait_for_event () at /usr/lib64/libxcb.so.1
#3  0x00007ff071a003c9 in  () at /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007ff07fa8732f in  () at /usr/lib64/libQt5Core.so.5
#5  0x00007ff07eb960a4 in start_thread () at /lib64/libpthread.so.0
#6  0x00007ff07f39502d in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7ff085e7d7c0 (LWP 16743)):
[KCrash Handler]
#6  0x00007ff07f2e50c7 in raise () at /lib64/libc.so.6
#7  0x00007ff07f2e6478 in abort () at /lib64/libc.so.6
#8  0x00007ff07f322784 in  () at /lib64/libc.so.6
#9  0x00007ff07f328026 in malloc_printerr () at /lib64/libc.so.6
#10 0x00007ff07f328d53 in _int_free () at /lib64/libc.so.6
#11 0x00007ff0717ba3f1 in XIQueryDevice () at /usr/lib64/libXi.so.6
#12 0x00007ff071a21d74 in QXcbConnection::touchDeviceForId(int) () at /usr/lib64/libQt5XcbQpa.so.5
#13 0x00007ff071a234ed in QXcbConnection::xi2SetupDevices() () at /usr/lib64/libQt5XcbQpa.so.5
#14 0x00007ff071a23ba0 in QXcbConnection::xi2HandleHierachyEvent(void*) () at /usr/lib64/libQt5XcbQpa.so.5
#15 0x00007ff071a2593b in QXcbConnection::xi2HandleEvent(xcb_ge_event_t*) () at /usr/lib64/libQt5XcbQpa.so.5
#16 0x00007ff0719fe34d in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib64/libQt5XcbQpa.so.5
#17 0x00007ff071a0001b in QXcbConnection::processXcbEvents() () at /usr/lib64/libQt5XcbQpa.so.5
#18 0x00007ff07fc93ac6 in QObject::event(QEvent*) () at /usr/lib64/libQt5Core.so.5
#19 0x00007ff080fdde7c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#20 0x00007ff080fe2cc8 in QApplication::notify(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#21 0x00007ff07fc62e95 in QCoreApplication::notifyInternal(QObject*, QEvent*) () at /usr/lib64/libQt5Core.so.5
#22 0x00007ff07fc65057 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib64/libQt5Core.so.5
#23 0x00007ff07fcba8f3 in  () at /usr/lib64/libQt5Core.so.5
#24 0x00007ff07ba69c84 in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
#25 0x00007ff07ba69ed8 in  () at /usr/lib64/libglib-2.0.so.0
#26 0x00007ff07ba69f7c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#27 0x00007ff07fcb9d6c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#28 0x00007ff07fc60d53 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#29 0x00007ff07fc688f6 in QCoreApplication::exec() () at /usr/lib64/libQt5Core.so.5
#30 0x0000000000436b3d in main ()

Reported using DrKonqi

Comment 1 David Edmundson 2016-12-08 16:54:42 UTC

It's a bug in Qt, I'm pretty sure it's fixed in newer versions.
5.5 is really old. Please upgrade.

Comment 2 Stefan Kaerst 2016-12-12 10:32:55 UTC

thanks for your fast reply.

indeed this problem is gone after upgrade to opensuse leap 42.2
kde plasma: 5.8.3
kde framework: 5.26.0
qt version: 5.6.1         

btw: this version info cannot be copied out of kinfocenter. is there a way to get the version information without typing it manually?

Comment 3 Ralf Jung 2017-01-04 12:24:00 UTC

My guess would be that the crash is not entirely reproducible, which is why you don't see it... I think this is a duplicate of https://bugs.kde.org/show_bug.cgi?id=373865 which I am seeing with Qt 5.7.1.