Application: ksmserver ()

Qt Version: 5.5.1
Operating System: Linux 4.2.0-36-generic x86_64
Distribution: Ubuntu 15.10

-- Information about the crash:
- What I was doing when the application crashed: Either manually activating 'lock screen' or display sleep 

- Unusual behavior I noticed: No desktop manager or plasmashell; only existing open applications alive

The crash can be reproduced every time.

-- Backtrace:
Application: ksmserver (ksmserver), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#6  QXcbScreen::mapToNative (this=this@entry=0x0, rect=...) at qxcbscreen.cpp:267
#7  0x00007f1ef8f4d6e3 in QXcbWindow::mapToNative (this=<optimized out>, rect=..., screen=0x0) at qxcbwindow.cpp:199
#8  0x00007f1ef8f4eedb in QXcbWindow::propagateSizeHints (this=0x2588b90) at qxcbwindow.cpp:1606
#9  0x00007f1ef8f5406c in QXcbWindow::setGeometry (this=0x2588b90, rect=...) at qxcbwindow.cpp:709
#10 0x00007f1f0e33534a in ?? () from /usr/lib/x86_64-linux-gnu/libKScreenLocker.so.5
#11 0x00007f1f09ff3777 in QtPrivate::QSlotObjectBase::call (a=0x7ffcb727c3f0, r=0x2370c10, this=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#12 QMetaObject::activate (sender=sender@entry=0x2446c50, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=2, argv=argv@entry=0x7ffcb727c3f0) at kernel/qobject.cpp:3698
#13 0x00007f1f09ff40e7 in QMetaObject::activate (sender=sender@entry=0x2446c50, m=m@entry=0x7f1f0adc65a0 <QDesktopWidget::staticMetaObject>, local_signal_index=local_signal_index@entry=2, argv=argv@entry=0x7ffcb727c3f0) at kernel/qobject.cpp:3578
#14 0x00007f1f0a91b021 in QDesktopWidget::screenCountChanged (this=this@entry=0x2446c50, _t1=_t1@entry=0) at .moc/moc_qdesktopwidget.cpp:218
#15 0x00007f1f0a91c39d in QDesktopWidgetPrivate::_q_updateScreens (this=0x23aae40) at kernel/qdesktopwidget.cpp:117
#16 0x00007f1f09ff47b1 in QObject::event (this=this@entry=0x2446c50, e=e@entry=0x24a0040) at kernel/qobject.cpp:1239
#17 0x00007f1f0a90474b in QWidget::event (this=0x2446c50, event=0x24a0040) at kernel/qwidget.cpp:9105
#18 0x00007f1f0a8c19dc in QApplicationPrivate::notify_helper (this=this@entry=0x23505a0, receiver=receiver@entry=0x2446c50, e=e@entry=0x24a0040) at kernel/qapplication.cpp:3716
#19 0x00007f1f0a8c6ea6 in QApplication::notify (this=0x23519a0, receiver=0x2446c50, e=0x24a0040) at kernel/qapplication.cpp:3499
#20 0x00007f1f09fc4d7b in QCoreApplication::notifyInternal (this=0x23519a0, receiver=0x2446c50, event=event@entry=0x24a0040) at kernel/qcoreapplication.cpp:965
#21 0x00007f1f09fc7176 in QCoreApplication::sendEvent (event=0x24a0040, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:224
#22 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x234e940) at kernel/qcoreapplication.cpp:1593
#23 0x00007f1f09fc7658 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#24 0x00007f1f0a01b0e3 in postEventSourceDispatch (s=0x23b1a30) at kernel/qeventdispatcher_glib.cpp:271
#25 0x00007f1f0400fff7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007f1f04010250 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#27 0x00007f1f040102fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007f1f0a01b4ef in QEventDispatcherGlib::processEvents (this=0x23b1ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#29 0x00007f1f09fc250a in QEventLoop::exec (this=this@entry=0x7ffcb727cac0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#30 0x00007f1f09fca5ec in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#31 0x00007f1f0a2ffd1c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1530
#32 0x00007f1f0a8bde15 in QApplication::exec () at kernel/qapplication.cpp:2976
#33 0x00007f1f0e92f136 in kdemain (argc=1, argv=<optimized out>) at ../../ksmserver/main.cpp:349
#34 0x00007f1f0e56eac0 in __libc_start_main (main=0x4007a0 <main(int, char**)>, argc=1, argv=0x7ffcb727cd78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffcb727cd68) at libc-start.c:289
#35 0x00000000004007d9 in _start ()

Possible duplicates by query: bug 362075, bug 354934.

Reported using DrKonqi