Application: kmail (4.8.3)
KDE Platform Version: 4.8.3 (4.8.3)
Qt Version: 4.8.1
Operating System: Linux 3.2.12-gentoo x86_64
Distribution: "Gentoo Base System release 2.1"

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

I've tried to move a few messages from an IMAP folder to a local folder via mouse drag.
When I've tried to drop the messages onto the destination folder, it didn't react to mouse release and the cursor stayed overimposed with the messages symbol.
While holding the cursor over the target folder, I've tried to click.
KMail crashed immediatelly.
Checking the IMAP server via web interface, I've found that the folder got completely emptied.
I've immediately backed up the remnants in the cache ~/.local/share/akonadi/file_db_data and after a few minutes the files corresponding to messages in that folder disappeared from the cache.
Unfortunately, not all of the messages were in the cache when I did the backup, so I've LOST MESSAGES PERMANENTLY - no, they are NOT present in the target local folder, however the few messages I've tried to move are there.

Note that DrKonqi suggests a lot duplicates, however two things that look quite different
- all the other crashes talk about moving folders, I've just moved messages
- I haven't found any mention of data loss in other cases

-- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f1013452760 (LWP 2537))]

Thread 4 (Thread 0x7f0ff2feb700 (LWP 2592)):
#0  pthread_cond_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f1005735514 in scavengerThread (this=0x7f10060f10c0) at wtf/FastMalloc.cpp:2495
#2  WTF::TCMalloc_PageHeap::runScavengerThread (context=0x7f10060f10c0) at wtf/FastMalloc.cpp:1618
#3  0x00007f100e57ad0c in start_thread (arg=0x7f0ff2feb700) at pthread_create.c:301
#4  0x00007f1010760bed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 3 (Thread 0x7f0ff26ea700 (LWP 2595)):
#0  0x00007f1010757d13 in *__GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f100902eb84 in g_main_context_poll (n_fds=1, fds=0x7f0fec0013d0, timeout=-1, context=0x7f0fec000990, priority=<optimized out>) at gmain.c:3402
#2  g_main_context_iterate (context=0x7f0fec000990, block=1, dispatch=1, self=<optimized out>) at gmain.c:3084
#3  0x00007f100902f041 in g_main_context_iteration (context=0x7f0fec000990, may_block=1) at gmain.c:3152
#4  0x00007f10110e1106 in QEventDispatcherGlib::processEvents (this=0x7f0fec0008b0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:426
#5  0x00007f10110b0f92 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f10110b1245 in QEventLoop::exec (this=0x7f0ff26e9e20, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007f1010faf0e8 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#8  0x00007f1010fb175b in QThreadPrivate::start (arg=0xb674e0) at thread/qthread_unix.cpp:298
#9  0x00007f100e57ad0c in start_thread (arg=0x7f0ff26ea700) at pthread_create.c:301
#10 0x00007f1010760bed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 2 (Thread 0x7f0ff0a6c700 (LWP 7623)):
#0  pthread_cond_timedwait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:216
#1  0x00007f1010fb25d2 in wait (time=30000, this=0x2305b40) at thread/qwaitcondition_unix.cpp:84
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x2318ae8, time=30000) at thread/qwaitcondition_unix.cpp:158
#3  0x00007f1010fa5d9f in QThreadPoolThread::run (this=0x2319d30) at concurrent/qthreadpool.cpp:141
#4  0x00007f1010fb175b in QThreadPrivate::start (arg=0x2319d30) at thread/qthread_unix.cpp:298
#5  0x00007f100e57ad0c in start_thread (arg=0x7f0ff0a6c700) at pthread_create.c:301
#6  0x00007f1010760bed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 1 (Thread 0x7f1013452760 (LWP 2537)):
[KCrash Handler]
#6  QModelIndex (other=..., this=0x7fffd5ef8220) at ../../include/QtCore/../../src/corelib/kernel/qabstractitemmodel.h:65
#7  QSortFilterProxyModel::parent (this=0xa07630, child=<optimized out>) at itemviews/qsortfilterproxymodel.cpp:1659
#8  0x00007f1012e0d8df in parent (this=0x7fffd5ef8270) at /usr/include/qt4/QtCore/qabstractitemmodel.h:393
#9  KIdentityProxyModel::parent (this=0x13a3310, child=...) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdeui/itemviews/kidentityproxymodel.cpp:358
#10 0x00007f1012e0d8df in parent (this=0x7fffd5ef82e0) at /usr/include/qt4/QtCore/qabstractitemmodel.h:393
#11 KIdentityProxyModel::parent (this=0x13d2fd0, child=...) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdeui/itemviews/kidentityproxymodel.cpp:358
#12 0x00007f10110a8100 in parent (this=0x2537ea0) at kernel/qabstractitemmodel.h:393
#13 QAbstractItemModelPrivate::rowsAboutToBeInserted (this=0x13d6600, parent=..., first=0, last=<optimized out>) at kernel/qabstractitemmodel.cpp:575
#14 0x00007f10110a92f8 in QAbstractItemModel::beginInsertRows (this=0x13d2fd0, parent=<optimized out>, first=0, last=0) at kernel/qabstractitemmodel.cpp:2417
#15 0x00007f1012e0e3c4 in KIdentityProxyModelPrivate::_k_sourceRowsAboutToBeInserted (this=<optimized out>, parent=<optimized out>, start=0, end=0) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdeui/itemviews/kidentityproxymodel.cpp:700
#16 0x00007f10110c7743 in QMetaObject::activate (sender=0x13a3310, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffd5ef85b0) at kernel/qobject.cpp:3547
#17 0x00007f1011112634 in QAbstractItemModel::rowsAboutToBeInserted (this=<optimized out>, _t1=<optimized out>, _t2=0, _t3=0) at .moc/release-shared/moc_qabstractitemmodel.cpp:190
#18 0x00007f10110a92e8 in QAbstractItemModel::beginInsertRows (this=0x13a3310, parent=<optimized out>, first=0, last=0) at kernel/qabstractitemmodel.cpp:2416
#19 0x00007f1012e0e3c4 in KIdentityProxyModelPrivate::_k_sourceRowsAboutToBeInserted (this=<optimized out>, parent=<optimized out>, start=0, end=0) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdeui/itemviews/kidentityproxymodel.cpp:700
#20 0x00007f10110c7743 in QMetaObject::activate (sender=0xa07630, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffd5ef87e0) at kernel/qobject.cpp:3547
#21 0x00007f1011112634 in QAbstractItemModel::rowsAboutToBeInserted (this=<optimized out>, _t1=<optimized out>, _t2=0, _t3=0) at .moc/release-shared/moc_qabstractitemmodel.cpp:190
#22 0x00007f10110a92e8 in QAbstractItemModel::beginInsertRows (this=0xa07630, parent=<optimized out>, first=0, last=0) at kernel/qabstractitemmodel.cpp:2416
#23 0x00007f1011b744cc in QSortFilterProxyModelPrivate::insert_source_items (this=0xab9700, source_to_proxy=..., proxy_to_source=..., source_items=<optimized out>, source_parent=<optimized out>, orient=Qt::Vertical, emit_signal=true) at itemviews/qsortfilterproxymodel.cpp:683
#24 0x00007f1011b78089 in QSortFilterProxyModelPrivate::source_items_inserted (this=0xab9700, source_parent=..., start=<optimized out>, end=<optimized out>, orient=Qt::Vertical) at itemviews/qsortfilterproxymodel.cpp:806
#25 0x00007f1011b7845f in QSortFilterProxyModelPrivate::_q_sourceRowsInserted (this=0xab9700, source_parent=<optimized out>, start=<optimized out>, end=<optimized out>) at itemviews/qsortfilterproxymodel.cpp:1280
#26 0x00007f10110c7743 in QMetaObject::activate (sender=0x9f9010, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffd5ef8b80) at kernel/qobject.cpp:3547
#27 0x00007f1011112684 in QAbstractItemModel::rowsInserted (this=<optimized out>, _t1=<optimized out>, _t2=0, _t3=0) at .moc/release-shared/moc_qabstractitemmodel.cpp:197
#28 0x00007f10110ac5db in QAbstractItemModel::endInsertRows (this=0x9f9010) at kernel/qabstractitemmodel.cpp:2433
#29 0x00007f100cfb2f85 in Akonadi::EntityTreeModelPrivate::insertCollection (this=0xab5cf0, collection=..., parent=...) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/entitytreemodel_p.cpp:713
#30 0x00007f100cfb6c8e in Akonadi::EntityTreeModelPrivate::monitoredCollectionAdded (this=0xab5cf0, collection=..., parent=...) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/entitytreemodel_p.cpp:750
#31 0x00007f10110c7743 in QMetaObject::activate (sender=0x9d6680, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffd5ef8ec0) at kernel/qobject.cpp:3547
#32 0x00007f100cfef5ea in Akonadi::Monitor::collectionAdded (this=<optimized out>, _t1=<optimized out>, _t2=<optimized out>) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3_build/akonadi/monitor.moc:231
#33 0x00007f100cff1db2 in Akonadi::MonitorPrivate::emitCollectionNotification (this=0xaaea60, msg=..., col=..., par=<optimized out>, dest=<optimized out>) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/monitor_p.cpp:600
#34 0x00007f100cff4be1 in Akonadi::MonitorPrivate::emitNotification (this=0xaaea60, msg=...) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/monitor_p.cpp:285
#35 0x00007f100cf553a1 in Akonadi::ChangeRecorderPrivate::emitNotification (this=0xaaea60, msg=<optimized out>) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/changerecorder_p.h:60
#36 0x00007f100cff3604 in Akonadi::MonitorPrivate::flushPipeline (this=0xaaea60) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/monitor_p.cpp:429
#37 0x00007f100cff36a9 in Akonadi::MonitorPrivate::dataAvailable (this=0xaaea60) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/monitor_p.cpp:438
#38 0x00007f10110c7743 in QMetaObject::activate (sender=0x1273e40, m=<optimized out>, local_signal_index=<optimized out>, argv=0x0) at kernel/qobject.cpp:3547
#39 0x00007f100cf5b7d3 in Akonadi::EntityCache<Akonadi::Collection, Akonadi::CollectionFetchJob, Akonadi::CollectionFetchScope>::processResult (this=0x1273e40, job=<optimized out>) at /var/tmp/portage/kde-base/kdepimlibs-4.8.3/work/kdepimlibs-4.8.3/akonadi/entitycache_p.h:192
#40 0x00007f10110c7743 in QMetaObject::activate (sender=0x28c5360, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffd5ef9650) at kernel/qobject.cpp:3547
#41 0x00007f1012850852 in KJob::result (this=<optimized out>, _t1=0x28c5360) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3_build/kdecore/kjob.moc:208
#42 0x00007f1012850890 in KJob::emitResult (this=0x28c5360) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdecore/jobs/kjob.cpp:318
#43 0x00007f10110c6b86 in QObject::event (this=0x28c5360, e=<optimized out>) at kernel/qobject.cpp:1195
#44 0x00007f10115e3314 in QApplicationPrivate::notify_helper (this=0xfb7730, receiver=0x28c5360, e=0x1a942b0) at kernel/qapplication.cpp:4554
#45 0x00007f10115e7f0f in QApplication::notify (this=<optimized out>, receiver=0x28c5360, e=0x1a942b0) at kernel/qapplication.cpp:4415
#46 0x00007f1012e50b76 in KApplication::notify (this=0x7fffd5efa180, receiver=0x28c5360, event=0x1a942b0) at /var/tmp/portage/kde-base/kdelibs-4.8.3/work/kdelibs-4.8.3/kdeui/kernel/kapplication.cpp:311
#47 0x00007f10110b1f6b in QCoreApplication::notifyInternal (this=0x7fffd5efa180, receiver=0x28c5360, event=0x1a942b0) at kernel/qcoreapplication.cpp:876
#48 0x00007f10110b5527 in sendEvent (event=0x1a942b0, receiver=0x28c5360) at kernel/qcoreapplication.h:231
#49 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x95b7b0) at kernel/qcoreapplication.cpp:1500
#50 0x00007f10110e0f13 in sendPostedEvents () at kernel/qcoreapplication.h:236
#51 postEventSourceDispatch (s=<optimized out>) at kernel/qeventdispatcher_glib.cpp:279
#52 0x00007f100902e672 in g_main_dispatch (context=0xfb9ce0) at gmain.c:2441
#53 g_main_context_dispatch (context=0xfb9ce0) at gmain.c:3011
#54 0x00007f100902ee68 in g_main_context_iterate (context=0xfb9ce0, block=1, dispatch=1, self=<optimized out>) at gmain.c:3089
#55 0x00007f100902f041 in g_main_context_iteration (context=0xfb9ce0, may_block=1) at gmain.c:3152
#56 0x00007f10110e10af in QEventDispatcherGlib::processEvents (this=0x95b060, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#57 0x00007f101168849e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#58 0x00007f10110b0f92 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#59 0x00007f10110b1245 in QEventLoop::exec (this=0x7fffd5efa050, flags=...) at kernel/qeventloop.cpp:204
#60 0x00007f10110b59cb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#61 0x00000000004033ae in main (argc=<optimized out>, argv=<optimized out>) at /var/tmp/portage/kde-base/kmail-4.8.3/work/kmail-4.8.3/kmail/main.cpp:145

Possible duplicates by query: bug 302138, bug 302116, bug 301713, bug 301693, bug 298952.

Reported using DrKonqi