Application: kontact (4.13 pre)
KDE Platform Version: 4.12.60 (Compiled from sources)
Qt Version: 4.8.6
Operating System: Linux 3.13.2-2-ARCH x86_64
Distribution: "Arch Linux"

-- Information about the crash:
There are a few mailing list I mark as read after reading all the subjects of the unread emails (since that's the only part I'm interested about). If I mark as read too many folders fast enough kontact will crash.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Kontact (kontact), signal: Aborted
Using host libthread_db library "/usr/lib/libthread_db.so.1".
To enable execution of this file add
	add-auto-load-safe-path /usr/lib/libstdc++.so.6.0.19-gdb.py
line to your configuration file "/home/afiestas/.gdbinit".
To completely disable this security protection add
	set auto-load safe-path /
line to your configuration file "/home/afiestas/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
	info "(gdb)Auto-loading safe path"
[Current thread is 1 (Thread 0x7eff4850c7c0 (LWP 24214))]

Thread 3 (Thread 0x7eff2422e700 (LWP 24215)):
#0  0x00007eff424b204f in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007eff46f895bb in WTF::TCMalloc_PageHeap::scavengerThread() () from /opt/qt4/lib/libQtWebKit.so.4
#2  0x00007eff46f88ba6 in WTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /opt/qt4/lib/libQtWebKit.so.4
#3  0x00007eff424ae0a2 in start_thread () from /usr/lib/libpthread.so.0
#4  0x00007eff41180d1d in clone () from /usr/lib/libc.so.6

Thread 2 (Thread 0x7eff23a2d700 (LWP 24216)):
#0  0x00007eff4117835d in poll () from /usr/lib/libc.so.6
#1  0x00007eff3f266584 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007eff3f26668c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007eff41e74862 in QEventDispatcherGlib::processEvents (this=0x7eff1c0008c0, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventdispatcher_glib.cpp:427
#4  0x00007eff41e353c7 in QEventLoop::processEvents (this=0x7eff23a2cda0, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventloop.cpp:149
#5  0x00007eff41e3555a in QEventLoop::exec (this=0x7eff23a2cda0, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventloop.cpp:204
#6  0x00007eff41cfae65 in QThread::exec (this=0x244b1b0) at /home/afiestas/kde4/source/qt/src/corelib/thread/qthread.cpp:537
#7  0x00007eff41cfb012 in QThread::run (this=0x244b1b0) at /home/afiestas/kde4/source/qt/src/corelib/thread/qthread.cpp:604
#8  0x00007eff41cfd931 in QThreadPrivate::start (arg=0x244b1b0) at /home/afiestas/kde4/source/qt/src/corelib/thread/qthread_unix.cpp:349
#9  0x00007eff424ae0a2 in start_thread () from /usr/lib/libpthread.so.0
#10 0x00007eff41180d1d in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7eff4850c7c0 (LWP 24214)):
[KCrash Handler]
#6  0x00007eff410d0389 in raise () from /usr/lib/libc.so.6
#7  0x00007eff410d1788 in abort () from /usr/lib/libc.so.6
#8  0x00007eff41cf02ae in qt_message_output (msgType=QtFatalMsg, buf=0x21aed118 "ASSERT: \"flags.size() == 1\" in file /home/afiestas/kde4/source/kdepimlibs/akonadi/kmime/markascommand.cpp, line 102") at /home/afiestas/kde4/source/qt/src/corelib/global/qglobal.cpp:2359
#9  0x00007eff41cf042d in qt_message(QtMsgType, const char *, typedef __va_list_tag __va_list_tag *) (msgType=QtFatalMsg, msg=0x7eff41ebcaa8 "ASSERT: \"%s\" in file %s, line %d", ap=0x7fff09c3ef78) at /home/afiestas/kde4/source/qt/src/corelib/global/qglobal.cpp:2405
#10 0x00007eff41cf0bff in qFatal (msg=0x7eff41ebcaa8 "ASSERT: \"%s\" in file %s, line %d") at /home/afiestas/kde4/source/qt/src/corelib/global/qglobal.cpp:2588
#11 0x00007eff41cefe6e in qt_assert (assertion=0x7eff21396d56 "flags.size() == 1", file=0x7eff21396c90 "/home/afiestas/kde4/source/kdepimlibs/akonadi/kmime/markascommand.cpp", line=102) at /home/afiestas/kde4/source/qt/src/corelib/global/qglobal.cpp:2054
#12 0x00007eff213886c8 in MarkAsCommand::markMessages (this=this@entry=0x5dbc040) at /home/afiestas/kde4/source/kdepimlibs/akonadi/kmime/markascommand.cpp:102
#13 0x00007eff21388a63 in MarkAsCommand::slotFetchDone (this=0x5dbc040, job=<optimized out>) at /home/afiestas/kde4/source/kdepimlibs/akonadi/kmime/markascommand.cpp:73
#14 0x00007eff41e56754 in QMetaObject::activate (sender=0x23ff4620, m=0x7eff42b87ac0 <KJob::staticMetaObject>, local_signal_index=3, argv=0x7fff09c3f2e0) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qobject.cpp:3539
#15 0x00007eff427e8352 in KJob::result (this=this@entry=0x23ff4620, _t1=_t1@entry=0x23ff4620) at /home/afiestas/kde4/build/kdelibs/kdecore/kjob.moc:207
#16 0x00007eff427e8395 in KJob::emitResult (this=0x23ff4620) at /home/afiestas/kde4/source/kdelibs/kdecore/jobs/kjob.cpp:318
#17 0x00007eff41e5007d in QMetaCallEvent::placeMetaCall (this=0x1a898d10, object=0x23ff4620) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qobject.cpp:524
#18 0x00007eff41e51301 in QObject::event (this=0x23ff4620, e=0x1a898d10) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qobject.cpp:1194
#19 0x00007eff4305c41c in QApplicationPrivate::notify_helper (this=0x2460050, receiver=0x23ff4620, e=0x1a898d10) at /home/afiestas/kde4/source/qt/src/gui/kernel/qapplication.cpp:4562
#20 0x00007eff430599b8 in QApplication::notify (this=0x7fff09c40060, receiver=0x23ff4620, e=0x1a898d10) at /home/afiestas/kde4/source/qt/src/gui/kernel/qapplication.cpp:3944
#21 0x00007eff440a1c46 in KApplication::notify (this=0x7fff09c40060, receiver=0x23ff4620, event=0x1a898d10) at /home/afiestas/kde4/source/kdelibs/kdeui/kernel/kapplication.cpp:311
#22 0x00007eff41e380d9 in QCoreApplication::notifyInternal (this=0x7fff09c40060, receiver=0x23ff4620, event=0x1a898d10) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qcoreapplication.cpp:953
#23 0x00007eff464d8ee9 in QCoreApplication::sendEvent(QObject*, QEvent*) () from /opt/qt4/lib/libQtWebKit.so.4
#24 0x00007eff41e39106 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x23f2310) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qcoreapplication.cpp:1577
#25 0x00007eff41e38d29 in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qcoreapplication.cpp:1470
#26 0x00007eff43129ba5 in QCoreApplication::sendPostedEvents () at ../../include/QtCore/../../../../source/qt/src/corelib/kernel/qcoreapplication.h:236
#27 0x00007eff41e73f9c in postEventSourceDispatch (s=0x246f2f0) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventdispatcher_glib.cpp:280
#28 0x00007eff3f266296 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007eff3f2665e8 in ?? () from /usr/lib/libglib-2.0.so.0
#30 0x00007eff3f26668c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007eff41e7483f in QEventDispatcherGlib::processEvents (this=0x23f3c10, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventdispatcher_glib.cpp:425
#32 0x00007eff43135d9c in QGuiEventDispatcherGlib::processEvents (this=0x23f3c10, flags=...) at /home/afiestas/kde4/source/qt/src/gui/kernel/qguieventdispatcher_glib.cpp:204
#33 0x00007eff41e353c7 in QEventLoop::processEvents (this=0x7fff09c3ff50, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventloop.cpp:149
#34 0x00007eff41e3555a in QEventLoop::exec (this=0x7fff09c3ff50, flags=...) at /home/afiestas/kde4/source/qt/src/corelib/kernel/qeventloop.cpp:204
#35 0x00007eff41e3876c in QCoreApplication::exec () at /home/afiestas/kde4/source/qt/src/corelib/kernel/qcoreapplication.cpp:1225
#36 0x00007eff430595a2 in QApplication::exec () at /home/afiestas/kde4/source/qt/src/gui/kernel/qapplication.cpp:3823
#37 0x0000000000403427 in main (argc=1, argv=0x7fff09c401a8) at /home/afiestas/kde4/source/kdepim/kontact/src/main.cpp:219

Reported using DrKonqi