Bug 359001

Application: plasmashell (5.5.3)

Qt Version: 5.5.1
Operating System: Linux 4.2.0-27-generic x86_64
Distribution: Ubuntu 15.10

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

I suspended my laptop yesterday and left the DisplayPort cable plugged in, this morning I opened the lid, it took a little bit longer to get the login screen than expected but after about 10 seconds it appeared (it's usually right away). I have two Displayport screens in an MST chain (DP1-1 and DP1-2), neither showed the login screen. The LED light on the screen shows that they are in power save mode.

I signed in and neither external screen showed up. KDE still thinks the screens are active though as most of the applications are on the external displays.

 I was able to bring up DIsplay Configuration and change the Primary Display to laptop screen. Upon hitting Apply, Plasma crashed and produced the backtrace in this report.

I have my panel at the top of the Laptop screen and I noted right clicking for More Actions > Move did not show the context menu as the context menu for each application was being launched above the panel into the display regions for DP1-1 and DP1-2 that could not be seen.

Display Configuration screen layout is like this:
[ DP1-2 ] [ DP1-1]
       [ Laptop ]





- Unusual behavior I noticed:

1. Desktops on external screens do not show even though they were working pre-suspend
2. Panel at the top and after crash the context menu launches above the panel, rendering the context menu inaccessible. Moving the panel to the bottom allows context menu to be accessed via right click on the application.
3. In some instances when the DP cable is plugged and unplugged the laptop desktop freezes then splits down the middle. It shows the right half of the desktop on the left and the left half on the right. KDE is unusable at this point.


This happens nearly every day when resuming from suspend. In order to get  a working setup I have to close all applications, especially running virtual machines ot avoid corrupted databases, switch to runlevel 1, rm ~/.local/share/kscreen/* and then sudo killall sddm.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7facb99d3800 (LWP 21501))]

Thread 8 (Thread 0x7faca4d8c700 (LWP 21503)):
#0  0x00007facb40da8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007facb81a8bd2 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007facb81aa74f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007faca6ed57e9 in QXcbEventReader::run (this=0x1c175e0) at qxcbconnection.cpp:1229
#4  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x1c175e0) at thread/qthread_unix.cpp:331
#5  0x00007facb38bc6aa in start_thread (arg=0x7faca4d8c700) at pthread_create.c:333
#6  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7fac9e405700 (LWP 21510)):
#0  0x00007facb40da8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007facb0e711ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007facb4a0850b in QEventDispatcherGlib::processEvents (this=0x7fac980008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7fac9e404da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007facb47cbac4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007facb7079c35 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x1cf2e00) at thread/qthread_unix.cpp:331
#8  0x00007facb38bc6aa in start_thread (arg=0x7fac9e405700) at pthread_create.c:333
#9  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fac92fa5700 (LWP 21535)):
#0  0x00007facb40da8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007facb0e711ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007facb4a0850b in QEventDispatcherGlib::processEvents (this=0x7fac8c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7fac92fa4da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007facb47cbac4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007facb7079c35 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x1ffa4c0) at thread/qthread_unix.cpp:331
#8  0x00007facb38bc6aa in start_thread (arg=0x7fac92fa5700) at pthread_create.c:333
#9  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fac911c8700 (LWP 21538)):
#0  0x00007facb40da8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007facb0e711ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007facb4a0850b in QEventDispatcherGlib::processEvents (this=0x7fac840008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7fac911c7da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007facb47cbac4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007facb7079c35 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x20db8d0) at thread/qthread_unix.cpp:331
#8  0x00007facb38bc6aa in start_thread (arg=0x7fac911c8700) at pthread_create.c:333
#9  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fac8b7bc700 (LWP 21544)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007facb9422194 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007facb94221d9 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007facb38bc6aa in start_thread (arg=0x7fac8b7bc700) at pthread_create.c:333
#4  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fac88e6f700 (LWP 21545)):
#0  __GI___pthread_getspecific (key=3) at pthread_getspecific.c:31
#1  0x00007facb0e97e10 in g_thread_self () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007facb0e7016c in g_main_context_acquire () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007facb0e710a5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007facb4a0850b in QEventDispatcherGlib::processEvents (this=0x7fac000008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#6  0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7fac88e6ed50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#7  0x00007facb47cbac4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#8  0x00007facb7a022a6 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x23c4f00) at thread/qthread_unix.cpp:331
#10 0x00007facb38bc6aa in start_thread (arg=0x7fac88e6f700) at pthread_create.c:333
#11 0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fabf1995700 (LWP 21551)):
#0  0x00007facb40da8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007facb0e711ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007facb4a0850b in QEventDispatcherGlib::processEvents (this=0x7fabec0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7fabf1994d80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007facb47cbac4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007fabf3c2c8f7 in KCupsConnection::run() () from /usr/lib/x86_64-linux-gnu/libkcupslib.so
#7  0x00007facb47d0a6e in QThreadPrivate::start (arg=0x4842610) at thread/qthread_unix.cpp:331
#8  0x00007facb38bc6aa in start_thread (arg=0x7fabf1995700) at pthread_create.c:333
#9  0x00007facb40e5eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7facb99d3800 (LWP 21501)):
[KCrash Handler]
#6  0x00007facb6f4351a in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007facb6f437e4 in QV4::ExecutionEngine::toVariant(QV4::Value const&, int, bool) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007facb6ff8280 in QQmlPropertyPrivate::writeBinding(QObject*, QQmlPropertyData const&, QQmlContextData*, QQmlJavaScriptExpression*, QV4::Value const&, bool, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#9  0x00007facb706614f in QQmlBinding::update(QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007facb706657e in QQmlBinding::expressionChanged(QQmlJavaScriptExpression*) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#11 0x00007facb70424be in QQmlNotifier::emitNotify(QQmlNotifierEndpoint*, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#12 0x00007facb6fe508c in QQmlData::signalEmitted(QAbstractDeclarativeData*, QObject*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#13 0x00007facb49e01f0 in QMetaObject::activate (sender=sender@entry=0x41a7060, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=8, argv=argv@entry=0x7ffdd44c3b30) at kernel/qobject.cpp:3599
#14 0x00007facb49e10e7 in QMetaObject::activate (sender=sender@entry=0x41a7060, m=m@entry=0x69e440 <PanelView::staticMetaObject>, local_signal_index=local_signal_index@entry=8, argv=argv@entry=0x7ffdd44c3b30) at kernel/qobject.cpp:3578
#15 0x0000000000440962 in PanelView::screenChangedProxy (this=this@entry=0x41a7060, _t1=_t1@entry=0x1c18e00) at ./moc_panelview.cpp:449
#16 0x0000000000445bc4 in PanelView::<lambda(QScreen*)>::operator() (screen=0x1c18e00, __closure=<synthetic pointer>) at ../../shell/panelview.cpp:727
#17 QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<QScreen*>, void, PanelView::showEvent(QShowEvent*)::<lambda(QScreen*)> >::call (arg=<optimized out>, f=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:495
#18 QtPrivate::Functor<PanelView::showEvent(QShowEvent*)::<lambda(QScreen*)>, 1>::call<QtPrivate::List<QScreen*>, void> (arg=<optimized out>, f=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:552
#19 QtPrivate::QFunctorSlotObject<PanelView::showEvent(QShowEvent*)::<lambda(QScreen*)>, 1, QtPrivate::List<QScreen*>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=<optimized out>, this_=<optimized out>, r=<optimized out>, a=<optimized out>, ret=<optimized out>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject_impl.h:192
#20 0x00007facb49e0777 in QtPrivate::QSlotObjectBase::call (a=0x7ffdd44c3c90, r=0x41a7060, this=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#21 QMetaObject::activate (sender=sender@entry=0x41a7060, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffdd44c3c90) at kernel/qobject.cpp:3698
#22 0x00007facb49e10e7 in QMetaObject::activate (sender=sender@entry=0x41a7060, m=m@entry=0x7facb5136580 <QWindow::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffdd44c3c90) at kernel/qobject.cpp:3578
#23 0x00007facb4cf818f in QWindow::screenChanged (this=this@entry=0x41a7060, _t1=_t1@entry=0x1c18e00) at .moc/moc_qwindow.cpp:631
#24 0x00007facb4cf90a5 in QWindowPrivate::emitScreenChangedRecursion (this=this@entry=0x41a7160, newScreen=newScreen@entry=0x1c18e00) at kernel/qwindow.cpp:360
#25 0x00007facb4cfc375 in QWindowPrivate::setTopLevelScreen (this=0x41a7160, newScreen=0x1c18e00, recreate=<optimized out>) at kernel/qwindow.cpp:384
#26 0x00007facb4cf62f5 in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x4297770) at kernel/qguiapplication.cpp:1611
#27 0x00007facb4cda228 in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:625
#28 0x00007faca6f070b0 in userEventSourceDispatch (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#29 0x00007facb0e70ff7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007facb0e71250 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007facb0e712fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#32 0x00007facb4a084ef in QEventDispatcherGlib::processEvents (this=0x1c41520, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#33 0x00007facb49af50a in QEventLoop::exec (this=this@entry=0x7ffdd44c4010, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#34 0x00007facb49b75ec in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#35 0x00007facb4cebd1c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1530
#36 0x00007facb54b2e15 in QApplication::exec () at kernel/qapplication.cpp:2976
#37 0x000000000043258a in main (argc=2, argv=<optimized out>) at ../../shell/main.cpp:179

Possible duplicates by query: bug 348091, bug 347224, bug 347223, bug 347221.

Reported using DrKonqi