Application: kwin (4.10.1)
KDE Platform Version: 4.10.1
Qt Version: 4.8.4
Operating System: Linux 3.8.4-202.fc18.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
Steps to reproduce:
1) Open window shortcut setting: right click on a window title -> "more actions" -> "window shortcut".
2) Press the recording button.
3) Press the keyboard menu button (several times maybe).
4) Observe the warning message with something like "this key cannot be assigned ..." (it disappears very quick) and then the crash window.

Note: menu button is assigned to switching keyboard layout for me:

$ setxkbmap -print
xkb_keymap {
        xkb_keycodes  { include "evdev+aliases(qwerty)" };
        xkb_types     { include "complete"      };
        xkb_compat    { include "complete"      };
        xkb_symbols   { include "pc+us+ru:2+ua:3+inet(evdev)+group(menu_toggle)+compose(caps)+terminate(ctrl_alt_bksp)" };
        xkb_geometry  { include "dell(latitude)"        };
};

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
81	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7f62a5376880 (LWP 2900))]

Thread 2 (Thread 0x7f6299173700 (LWP 2902)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:217
#1  0x00000038b707be17 in QWaitCondition::wait(QMutex*, unsigned long) () from /lib64/libQtCore.so.4
#2  0x00000038b706f69f in QThreadPoolThread::run() () from /lib64/libQtCore.so.4
#3  0x00000038b707b95c in QThreadPrivate::start(void*) () from /lib64/libQtCore.so.4
#4  0x00000038af807d15 in start_thread (arg=0x7f6299173700) at pthread_create.c:308
#5  0x00000038af0f246d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:114

Thread 1 (Thread 0x7f62a5376880 (LWP 2900)):
[KCrash Handler]
#5  0x00000038b7189048 in QObject::killTimer(int) () from /lib64/libQtCore.so.4
#6  0x00000038b7194ab1 in QTimer::stop() () from /lib64/libQtCore.so.4
#7  0x00000035024f033b in KKeySequenceWidgetPrivate::doneRecording(bool) () from /lib64/libkdeui.so.5
#8  0x00000035024f0648 in KKeySequenceButton::keyPressEvent(QKeyEvent*) () from /lib64/libkdeui.so.5
#9  0x00000035024ed74d in KKeySequenceButton::event(QEvent*) () from /lib64/libkdeui.so.5
#10 0x0000003f441ca5cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#11 0x0000003f441cf5c4 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#12 0x00000035024473c6 in KApplication::notify(QObject*, QEvent*) () from /lib64/libkdeui.so.5
#13 0x00000038b7177abe in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQtCore.so.4
#14 0x0000003f4426699a in QKeyMapper::sendKeyEvent(QWidget*, bool, QEvent::Type, int, QFlags<Qt::KeyboardModifier>, QString const&, bool, int, unsigned int, unsigned int, unsigned int, bool*) () from /lib64/libQtGui.so.4
#15 0x0000003f44266dd1 in QKeyMapperPrivate::translateKeyEvent(QWidget*, _XEvent const*, bool) () from /lib64/libQtGui.so.4
#16 0x0000003f442446d8 in QApplication::x11ProcessEvent(_XEvent*) () from /lib64/libQtGui.so.4
#17 0x0000003f4426b4f9 in QEventDispatcherX11::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtGui.so.4
#18 0x00000038b717680f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#19 0x00000038b7176a98 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#20 0x00000038b717b888 in QCoreApplication::exec() () from /lib64/libQtCore.so.4
#21 0x0000003ed6c67d6a in kdemain () from /lib64/libkdeinit4_kwin.so
#22 0x00000038af021a05 in __libc_start_main (main=0x400960 <main>, argc=3, ubp_av=0x7fffba73b288, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffba73b278) at libc-start.c:225
#23 0x0000000000400991 in _start ()

Reported using DrKonqi