Application: kwin_x11 (5.9.5)

Qt Version: 5.7.1
Frameworks Version: 5.34.0
Operating System: Linux 4.10.0-sabayon x86_64
Distribution: "Sabayon Linux amd64 17.04"

-- Information about the crash:
- What I was doing when the application crashed:
Just opened k3b while system was using qtcurve theme.

- Unusual behavior I noticed:
K3b ceased to have a titlebar with buttons

- Custom settings of the application:
using qtcurve-1.8.18-r1 Leichtsinn theme (most likely the culprit) and global menus.

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
[KCrash Handler]
#6  0x00007f26e4e25dbe in QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) () from /usr/lib64/libQt5Core.so.5
#7  0x00007f26e408d1fb in ?? () from /usr/lib64/libQt5Script.so.5
#8  0x00007f26e408d2d0 in ?? () from /usr/lib64/libQt5Script.so.5
#9  0x00007f26e408d582 in QScriptEngine::newQObject(QObject*, QScriptEngine::ValueOwnership, QFlags<QScriptEngine::QObjectWrapOption> const&) () from /usr/lib64/libQt5Script.so.5
#10 0x00007f26e6ae1fec in ?? () from /usr/lib64/libkwin.so.5
#11 0x00007f26e408d952 in ?? () from /usr/lib64/libQt5Script.so.5
#12 0x00007f26e40b363e in ?? () from /usr/lib64/libQt5Script.so.5
#13 0x00007f26e40bafe5 in ?? () from /usr/lib64/libQt5Script.so.5
#14 0x00007f26e4e215f7 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib64/libQt5Core.so.5
#15 0x00007f26e468a6e8 in KWin::EffectsHandler::desktopPresenceChanged(KWin::EffectWindow*, int, int) () from /usr/lib64/libkwineffects.so.10
#16 0x00007f26e468b71b in ?? () from /usr/lib64/libkwineffects.so.10
#17 0x00007f26e4e2255a in QObject::event(QEvent*) () from /usr/lib64/libQt5Core.so.5
#18 0x00007f26e562d8bc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#19 0x00007f26e5634808 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#20 0x00007f26e4dfcad8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib64/libQt5Core.so.5
#21 0x00007f26e4dfed5b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib64/libQt5Core.so.5
#22 0x00007f26e4e42112 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#23 0x00007f26d055345d in ?? () from /usr/lib64/libQt5XcbQpa.so.5
#24 0x00007f26e4dfb89a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#25 0x00007f26e4e02f6d in QCoreApplication::exec() () from /usr/lib64/libQt5Core.so.5
#26 0x00007f26e73dbf92 in kdemain () from /usr/lib64/libkdeinit5_kwin_x11.so
#27 0x00007f26e6e23954 in __libc_start_main () from /lib64/libc.so.6
#28 0x0000000000400809 in _start ()

Possible duplicates by query: bug 380808, bug 380370, bug 380207, bug 380106, bug 380048.

Reported using DrKonqi