Application: kmail (4.14.6)
KDE Platform Version: 4.14.6
Qt Version: 4.8.6
Operating System: Linux 3.19.0-18-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
Kmail crashed when i was deleting a folder, not an expert but my random guess by looking at the backtrace it may have to do with the fact that i had a filter rule using that folder as destination.

-- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f10e249f800 (LWP 21667))]

Thread 4 (Thread 0x7f10ba26d700 (LWP 21672)):
#0  0x00007f10dd008da0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f10d3b3581d in WTF::TCMalloc_PageHeap::scavengerThread() () at /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#2  0x00007f10d3b35859 in  () at /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#3  0x00007f10dd0036aa in start_thread (arg=0x7f10ba26d700) at pthread_create.c:333
#4  0x00007f10df760eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f1078a95700 (LWP 21673)):
#0  0x00007f10dd008da0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f10d387620d in JSC::BlockAllocator::blockFreeingThreadMain() () at /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#2  0x00007f10d3b64fd6 in WTF::wtfThreadEntryPoint(void*) () at /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#3  0x00007f10dd0036aa in start_thread (arg=0x7f1078a95700) at pthread_create.c:333
#4  0x00007f10df760eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f10739f0700 (LWP 21674)):
#0  0x00007f10df7558dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f10d73c8ebc in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7f106c0013e0, timeout=9999, context=0x7f106c0009a0) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:4103
#2  0x00007f10d73c8ebc in g_main_context_iterate (context=context@entry=0x7f106c0009a0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3803
#3  0x00007f10d73c8fcc in g_main_context_iteration (context=0x7f106c0009a0, may_block=1) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3869
#4  0x00007f10e0df987e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f106c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:452
#5  0x00007f10e0dc8d21 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f10739efdd0, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f10e0dc9085 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f10739efdd0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007f10e0cbce89 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:538
#8  0x00007f10e0cbf6ff in QThreadPrivate::start(void*) (arg=0x287ea80) at thread/qthread_unix.cpp:349
#9  0x00007f10dd0036aa in start_thread (arg=0x7f10739f0700) at pthread_create.c:333
#10 0x00007f10df760eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f10e249f800 (LWP 21667)):
[KCrash Handler]
#6  0x00007f10dc0aa039 in Akonadi::FavoriteCollectionsModel::removeCollection(Akonadi::Collection const&) (this=0x0, collection=...) at ../../akonadi/favoritecollectionsmodel.cpp:294
#7  0x00007f10e130f92e in  () at /usr/lib/libkmailprivate.so.4
#8  0x00007f10e0ddf1ec in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=0x26d6440, m=m@entry=0x7f10dc44b2c0 <Akonadi::Monitor::staticMetaObject>, local_signal_index=local_signal_index@entry=16, argv=argv@entry=0x7ffdc3998230) at kernel/qobject.cpp:3567
#9  0x00007f10dc0e0a45 in Akonadi::Monitor::collectionRemoved(Akonadi::Collection const&) (this=<optimized out>, _t1=...) at ./moc_monitor.cpp:343
#10 0x00007f10dc0ebe0e in Akonadi::MonitorPrivate::emitCollectionNotification(Akonadi::NotificationMessageV3 const&, Akonadi::Collection const&, Akonadi::Collection const&, Akonadi::Collection const&) (this=this@entry=0x277a2b0, msg=..., col=..., par=..., dest=...) at ../../akonadi/monitor_p.cpp:958
#11 0x00007f10dc0ecb04 in Akonadi::MonitorPrivate::emitNotification(Akonadi::NotificationMessageV3 const&) (this=0x277a2b0, msg=...) at ../../akonadi/monitor_p.cpp:504
#12 0x00007f10dc0e875c in Akonadi::MonitorPrivate::dispatchNotifications() (this=this@entry=0x277a2b0) at ../../akonadi/monitor_p.cpp:737
#13 0x00007f10dc0e9a3f in Akonadi::MonitorPrivate::slotNotify(QVector<Akonadi::NotificationMessageV3> const&) (this=this@entry=0x277a2b0, msgs=...) at ../../akonadi/monitor_p.cpp:707
#14 0x00007f10dc032564 in Akonadi::ChangeRecorderPrivate::slotNotify(QVector<Akonadi::NotificationMessageV3> const&) (this=0x277a2b0, msgs=...) at ../../akonadi/changerecorder_p.cpp:53
#15 0x00007f10e0ddf1ec in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=0x2696770, m=m@entry=0x7f10dc4541c0 <Akonadi::NotificationSource::staticMetaObject>, local_signal_index=<optimized out>, argv=argv@entry=0x7ffdc3998730) at kernel/qobject.cpp:3567
#16 0x00007f10dc1aa8a8 in Akonadi::NotificationSource::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_t1=..., this=<optimized out>) at moc_notificationsource_p.cpp:98
#17 0x00007f10dc1aa8a8 in Akonadi::NotificationSource::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at moc_notificationsource_p.cpp:49
#18 0x00007f10e0ddf1ec in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x260daf0, m=m@entry=0x7f10dc44f540 <OrgFreedesktopAkonadiNotificationSourceInterface::staticMetaObject>, local_signal_index=local_signal_index@entry=10, argv=argv@entry=0x7ffdc39988d0) at kernel/qobject.cpp:3567
#19 0x00007f10dc1a2700 in OrgFreedesktopAkonadiNotificationSourceInterface::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_t1=..., this=0x260daf0) at notificationsourceinterface.moc:264
#20 0x00007f10dc1a2700 in OrgFreedesktopAkonadiNotificationSourceInterface::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=_o@entry=0x260daf0, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=10, _a=_a@entry=0x7ffdc3998af0) at notificationsourceinterface.moc:119
#21 0x00007f10dc1a3603 in OrgFreedesktopAkonadiNotificationSourceInterface::qt_metacall(QMetaObject::Call, int, void**) (this=0x260daf0, _c=QMetaObject::InvokeMetaMethod, _id=10, _a=0x7ffdc3998af0) at notificationsourceinterface.moc:192
#22 0x00007f10ddb936a6 in QDBusConnectionPrivate::deliverCall(QObject*, int, QDBusMessage const&, QList<int> const&, int) (this=0x2431690, object=0x260daf0, msg=..., metaTypes=..., slotIdx=15) at qdbusintegrator.cpp:951
#23 0x00007f10e0de38e1 in QObject::event(QEvent*) (this=0x260daf0, e=<optimized out>) at kernel/qobject.cpp:1222
#24 0x00007f10e01119bc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x2447410, receiver=receiver@entry=0x260daf0, e=e@entry=0x169517b0) at kernel/qapplication.cpp:4570
#25 0x00007f10e01184d8 in QApplication::notify(QObject*, QEvent*) (this=this@entry=0x7ffdc3999510, receiver=receiver@entry=0x260daf0, e=e@entry=0x169517b0) at kernel/qapplication.cpp:4356
#26 0x00007f10e1edeb4a in KApplication::notify(QObject*, QEvent*) (this=0x7ffdc3999510, receiver=0x260daf0, event=0x169517b0) at ../../kdeui/kernel/kapplication.cpp:311
#27 0x00007f10e0dca1cd in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7ffdc3999510, receiver=receiver@entry=0x260daf0, event=event@entry=0x169517b0) at kernel/qcoreapplication.cpp:955
#28 0x00007f10e0dcda71 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (event=0x169517b0, receiver=0x260daf0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#29 0x00007f10e0dcda71 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x23c9220) at kernel/qcoreapplication.cpp:1579
#30 0x00007f10e0dcdf03 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1472
#31 0x00007f10e0df96ee in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#32 0x00007f10e0df96ee in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x2440fa0) at kernel/qeventdispatcher_glib.cpp:300
#33 0x00007f10d73c8c3d in g_main_context_dispatch (context=0x2445e50) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3122
#34 0x00007f10d73c8c3d in g_main_context_dispatch (context=context@entry=0x2445e50) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3737
#35 0x00007f10d73c8f20 in g_main_context_iterate (context=context@entry=0x2445e50, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3808
#36 0x00007f10d73c8fcc in g_main_context_iteration (context=0x2445e50, may_block=1) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3869
#37 0x00007f10e0df985e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x23cab20, flags=...) at kernel/qeventdispatcher_glib.cpp:450
#38 0x00007f10e01b9c66 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#39 0x00007f10e0dc8d21 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffdc3999150, flags=...) at kernel/qeventloop.cpp:149
#40 0x00007f10e0dc9085 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffdc3999150, flags=...) at kernel/qeventloop.cpp:204
#41 0x00007f10e0dceb09 in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1227
#42 0x0000000000402d82 in  ()
#43 0x00007f10df67aa40 in __libc_start_main (main=0x4022e0, argc=1, argv=0x7ffdc3999738, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffdc3999728) at libc-start.c:289
#44 0x000000000040325b in _start ()

Reported using DrKonqi