Application: kig ()

Qt Version: 5.4.0
Operating System: Linux 3.18.0-13-generic i686
Distribution: Ubuntu Vivid Vervet (development branch)

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

Sinnce upgrading to Kubuntu 15.04 Beta 1, Kig crashes every time I try to launch it. It does not even display the window

The crash can be reproduced every time.

-- Backtrace:
Application: kig (kig), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#7  KParts::ReadOnlyPart::url (this=0x0) at ../../src/readonlypart.cpp:60
#8  0x08050d56 in Kig::saveProperties(KConfigGroup&) ()
#9  0xb737fe07 in KMainWindow::savePropertiesInternal (this=0x84514b8, config=0x84f6010, number=1) at ../../src/kmainwindow.cpp:499
#10 0xb737ffae in KMWSessionManager::saveState (this=0xb74140d4 <(anonymous namespace)::Q_QGS_ksm::innerFunction()::holder>) at ../../src/kmainwindow.cpp:142
#11 0xb73c0b2b in KMWSessionManager::qt_static_metacall (_o=0xb74140d4 <(anonymous namespace)::Q_QGS_ksm::innerFunction()::holder>, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfb6b0f4) at moc_kmainwindow_p.cpp:69
#12 0xb610fbf1 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#13 0xb611022d in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#14 0xb64163e1 in QGuiApplication::saveStateRequest(QSessionManager&) () from /usr/lib/i386-linux-gnu/sse2/libQt5Gui.so.5
#15 0xb6418387 in QGuiApplicationPrivate::saveState() () from /usr/lib/i386-linux-gnu/sse2/libQt5Gui.so.5
#16 0xb64609df in QPlatformSessionManager::appSaveState() () from /usr/lib/i386-linux-gnu/sse2/libQt5Gui.so.5
#17 0xb2726050 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#18 0xb27262d1 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#19 0xb54455ea in _SmcProcessMessage (iceConn=0x84400e0, clientData=0x8440608, opcode=3, length=1, swap=0, replyWait=0x0, replyReadyRet=0xbfb6b6b8) at ../../src/sm_process.c:241
#20 0xb5435559 in IceProcessMessages (iceConn=0x84400e0, replyWait=0x0, replyReadyRet=0x0) at ../../src/process.c:386
#21 0xb2724b57 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#22 0xb610fbf1 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#23 0xb611022d in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#24 0xb6191c31 in QSocketNotifier::activated(int, QSocketNotifier::QPrivateSignal) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#25 0xb611dab9 in QSocketNotifier::event(QEvent*) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#26 0xb69df39a in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#27 0xb69e4bc1 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#28 0xb60dc7ba in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#29 0xb6138e35 in ?? () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#30 0xb4d2fd44 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#31 0xb4d30069 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#32 0xb4d30136 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#33 0xb6138614 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#34 0xb272a4c1 in ?? () from /usr/lib/i386-linux-gnu/qt5/plugins/platforms/libqxcb.so
#35 0xb60d99c3 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#36 0xb60d9e2a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#37 0xb60e1f45 in QCoreApplication::exec() () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#38 0xb6417931 in QGuiApplication::exec() () from /usr/lib/i386-linux-gnu/sse2/libQt5Gui.so.5
#39 0xb69daa64 in QApplication::exec() () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#40 0x0804e596 in main ()

Reported using DrKonqi