Application: kdeinit5 (5.3.0)

Qt Version: 5.4.1
Operating System: Linux 4.0.4-303.fc22.x86_64+debug x86_64
Distribution: "Fedora release 22 (Twenty Two)"

-- Information about the crash:
- What I was doing when the application crashed:
Have two keyboard layouts (English US and Russian (tried typewriter, DOS and legacy variants)), pressing Preview button with Russian layout selected in majority of cases crashes the KDE control module. 

- Custom settings of the application:
English and Russian keyboard layouts present

The crash can be reproduced sometimes.

-- Backtrace:
Application: KDE Control Module (kdeinit5), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f6cba78c840 (LWP 16353))]

Thread 2 (Thread 0x7f6c9bdf1700 (LWP 16354)):
#0  0x00007f6cb751f66d in poll () from /lib64/libc.so.6
#1  0x00007f6cb6709182 in _xcb_conn_wait () from /lib64/libxcb.so.1
#2  0x00007f6cb670ad07 in xcb_wait_for_event () from /lib64/libxcb.so.1
#3  0x00007f6c9d9395e9 in QXcbEventReader::run() () from /usr/lib64/qt5/plugins/platforms/libqxcb.so
#4  0x00007f6cb8129ede in QThreadPrivate::start(void*) () from /lib64/libQt5Core.so.5
#5  0x00007f6cb6b71555 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f6cb752af3d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f6cba78c840 (LWP 16353)):
[KCrash Handler]
#5  0x00007f6c995767d5 in KCMKeyboardWidget::previewLayout() () from /usr/lib64/qt5/plugins/kcm_keyboard.so
#6  0x00007f6c995de0ad in KCMKeyboardWidget::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib64/qt5/plugins/kcm_keyboard.so
#7  0x00007f6cb8339c46 in QMetaObject::activate(QObject*, int, int, void**) () from /lib64/libQt5Core.so.5
#8  0x00007f6cb935b572 in QAbstractButton::clicked(bool) () from /lib64/libQt5Widgets.so.5
#9  0x00007f6cb90c26d4 in QAbstractButtonPrivate::emitClicked() () from /lib64/libQt5Widgets.so.5
#10 0x00007f6cb90c3bb9 in QAbstractButtonPrivate::click() () from /lib64/libQt5Widgets.so.5
#11 0x00007f6cb90c3d34 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /lib64/libQt5Widgets.so.5
#12 0x00007f6cb900cdb8 in QWidget::event(QEvent*) () from /lib64/libQt5Widgets.so.5
#13 0x00007f6cb8fca7cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#14 0x00007f6cb8fd08ba in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#15 0x00007f6cb830924b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#16 0x00007f6cb8fcf332 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /lib64/libQt5Widgets.so.5
#17 0x00007f6cb9024240 in QWidgetWindow::handleMouseEvent(QMouseEvent*) () from /lib64/libQt5Widgets.so.5
#18 0x00007f6cb902658b in QWidgetWindow::event(QEvent*) () from /lib64/libQt5Widgets.so.5
#19 0x00007f6cb8fca7cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#20 0x00007f6cb8fcfe70 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#21 0x00007f6cb830924b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#22 0x00007f6cb8827cf5 in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) () from /lib64/libQt5Gui.so.5
#23 0x00007f6cb8829975 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /lib64/libQt5Gui.so.5
#24 0x00007f6cb880ee68 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Gui.so.5
#25 0x00007f6c9d965ba0 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /usr/lib64/qt5/plugins/platforms/libqxcb.so
#26 0x00007f6cb59a5a8a in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#27 0x00007f6cb59a5e20 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#28 0x00007f6cb59a5ecc in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#29 0x00007f6cb836073f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#30 0x00007f6cb8306a8a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#31 0x00007f6cb91beabd in QDialog::exec() () from /lib64/libQt5Widgets.so.5
#32 0x00007f6c9e02a0f5 in kdemain () from /lib64/libkdeinit5_kcmshell5.so
#33 0x000000000040a797 in handle_launcher_request(int, char const*) [clone .isra.22] ()
#34 0x000000000040cb0b in handle_requests(int) ()
#35 0x000000000040500a in main ()

Reported using DrKonqi