Application: kwrite (4.9.1)
KDE Platform Version: 4.9.1
Qt Version: 4.8.2
Operating System: Linux 3.5.0-14-generic x86_64
Distribution: Ubuntu quantal (development branch)

-- Information about the crash:
- What I was doing when the application crashed:
Clicking on "Help > About KWrite". Instant crash without displaying the About dialog. Crash can alway be reproduced. Backtrace for KWrite is attached, but it's the very same for other applications which have an "About <application name>" dialog. Thus, there is something wrong about the About dialog itself, not KWrite.

This behaviour started after I upgraded Kubuntu from Precise (with Kde 4.9.0) to Quantal Beta 1 (with Kde 4.9.1) yesterday using the instructions from here:
https://help.ubuntu.com/community/QuantalUpgrades/Kubuntu

Everything's running fine so far, but I noticed this little oddity with the "About <applicationname>" dialog always crashing. The "About Kde" dialog is working fine, btw.

The crash can be reproduced every time.

-- Backtrace:
Application: KWrite (kwrite), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f285ee55780 (LWP 4969))]

Thread 3 (Thread 0x7f2855e9b700 (LWP 4970)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f2856483ca7 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007f2856483cd9 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007f2862f7fe9a in start_thread (arg=0x7f2855e9b700) at pthread_create.c:308
#4  0x00007f28689c339d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f28544ae700 (LWP 4971)):
#0  __libc_enable_asynccancel () at ../nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S:60
#1  0x00007f28689b79c8 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:85
#2  0x00007f2862ab0de4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f2862ab0f04 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f28664cd036 in QEventDispatcherGlib::processEvents (this=0x7f284c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#5  0x00007f286649d63f in QEventLoop::processEvents (this=this@entry=0x7f28544addf0, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f286649d8c8 in QEventLoop::exec (this=0x7f28544addf0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007f28663a0a50 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#8  0x00007f286647df2f in QInotifyFileSystemWatcherEngine::run (this=0x16e1280) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x00007f28663a39eb in QThreadPrivate::start (arg=0x16e1280) at thread/qthread_unix.cpp:307
#10 0x00007f2862f7fe9a in start_thread (arg=0x7f28544ae700) at pthread_create.c:308
#11 0x00007f28689c339d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f285ee55780 (LWP 4969)):
[KCrash Handler]
#6  0x00007f28664b7f58 in QObject::connect (sender=0x7f2852d56be8 <vtable for Attica::KdePlatformDependent+232>, signal=0x7f28638caad0 "2authenticationRequired(QNetworkReply*,QAuthenticator*)", receiver=0x198a8e8, method=0x7f28638caa68 "1authenticate(QNetworkReply*,QAuthenticator*)", type=Qt::AutoConnection) at kernel/qobject.cpp:2551
#7  0x00007f28638bb2b0 in Attica::ProviderManager::ProviderManager() () from /usr/lib/libattica.so.0.3
#8  0x00007f2867b028d9 in KDEPrivate::KAboutApplicationPersonModel::KAboutApplicationPersonModel (this=0x198a8b0, personList=..., providerUrl=..., parent=<optimized out>) at ../../kdeui/dialogs/kaboutapplicationpersonmodel_p.cpp:39
#9  0x00007f2867affcfb in KAboutApplicationDialog::Private::init (this=0x1971c80, ad=<optimized out>, ad@entry=0x135e398, opt=...) at ../../kdeui/dialogs/kaboutapplicationdialog.cpp:209
#10 0x00007f2867b00617 in KAboutApplicationDialog::KAboutApplicationDialog (this=0x19606a0, aboutData=0x135e398, parent=<optimized out>) at ../../kdeui/dialogs/kaboutapplicationdialog.cpp:66
#11 0x00007f2867c2b55f in KHelpMenu::aboutApplication (this=0x1742dd0) at ../../kdeui/widgets/khelpmenu.cpp:280
#12 0x00007f28664b42df in QMetaObject::activate (sender=0x1756b70, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffc5113e90) at kernel/qobject.cpp:3547
#13 0x00007f2866e78932 in QAction::triggered (this=this@entry=0x1756b70, _t1=false) at .moc/release-shared/moc_qaction.cpp:277
#14 0x00007f2866e78b20 in QAction::activate (this=0x1756b70, event=<optimized out>) at kernel/qaction.cpp:1257
#15 0x00007f28672b6c23 in QMenuPrivate::activateCausedStack (this=this@entry=0x1777890, causedStack=..., action=action@entry=0x1756b70, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1028
#16 0x00007f28672bcf09 in QMenuPrivate::activateAction (this=0x1777890, action=0x1756b70, action_e=QAction::Trigger, self=<optimized out>) at widgets/qmenu.cpp:1120
#17 0x00007f2867c40b10 in KMenu::mouseReleaseEvent (this=0x1759120, e=0x7fffc5114a30) at ../../kdeui/widgets/kmenu.cpp:464
#18 0x00007f2866ece630 in QWidget::event (this=0x1759120, event=0x7fffc5114a30) at kernel/qwidget.cpp:8371
#19 0x00007f28672be1bb in QMenu::event (this=0x1759120, e=0x7fffc5114a30) at widgets/qmenu.cpp:2469
#20 0x00007f2866e7ed9c in QApplicationPrivate::notify_helper (this=this@entry=0x12f7080, receiver=receiver@entry=0x1759120, e=e@entry=0x7fffc5114a30) at kernel/qapplication.cpp:4556
#21 0x00007f2866e83a6b in QApplication::notify (this=<optimized out>, receiver=0x1759120, e=0x7fffc5114a30) at kernel/qapplication.cpp:4099
#22 0x00007f2867b87c86 in KApplication::notify (this=0x7fffc51156c0, receiver=0x1759120, event=0x7fffc5114a30) at ../../kdeui/kernel/kapplication.cpp:311
#23 0x00007f286649e8ee in QCoreApplication::notifyInternal (this=0x7fffc51156c0, receiver=0x1759120, event=0x7fffc5114a30) at kernel/qcoreapplication.cpp:915
#24 0x00007f2866e7fbd3 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#25 QApplicationPrivate::sendMouseEvent (receiver=0x1759120, event=0x7fffc5114a30, alienWidget=0x0, nativeWidget=0x1759120, buttonDown=0x7f286795c2e8 <qt_button_down>, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:3167
#26 0x00007f2866efd16c in QETWidget::translateMouseEvent (this=this@entry=0x1759120, event=event@entry=0x7fffc51151b0) at kernel/qapplication_x11.cpp:4551
#27 0x00007f2866efc19f in QApplication::x11ProcessEvent (this=0x7fffc51156c0, event=0x7fffc51151b0) at kernel/qapplication_x11.cpp:3732
#28 0x00007f2866f23d02 in x11EventSourceDispatch (s=0x12dae40, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#29 0x00007f2862ab0b15 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007f2862ab0e48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007f2862ab0f04 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#32 0x00007f28664cd016 in QEventDispatcherGlib::processEvents (this=0x12baad0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#33 0x00007f2866f2397e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#34 0x00007f286649d63f in QEventLoop::processEvents (this=this@entry=0x7fffc5115580, flags=...) at kernel/qeventloop.cpp:149
#35 0x00007f286649d8c8 in QEventLoop::exec (this=0x7fffc5115580, flags=...) at kernel/qeventloop.cpp:204
#36 0x00007f28664a2a88 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1187
#37 0x00007f2868cb8482 in kdemain (argc=1, argv=0x7fffc5115818) at ../../kwrite/kwritemain.cpp:680
#38 0x00007f28688f276d in __libc_start_main (main=0x400690 <main(int, char**)>, argc=1, ubp_av=0x7fffc5115818, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffc5115808) at libc-start.c:226
#39 0x00000000004006c1 in _start ()

Reported using DrKonqi