Application: kontact (4.4.11)
KDE Platform Version: 4.6.5 (4.6.5)
Qt Version: 4.7.3
Operating System: Linux 3.0.0-1-rt-amd64 x86_64
Distribution (Platform): Debian unstable

-- Information about the crash:
I tried to empty the Trash folder on an IMAP mailbox right after Kontact started up, and it reproducably crashes.

The crash can be reproduced every time.

-- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  0x00007f792a22d4d5 in MessageList::Core::View::setAllGroupsExpanded(bool) () from /usr/lib/libmessagelist.so.4
#7  0x00007f792ad31075 in ?? () from /usr/lib/libkmailprivate.so.4
#8  0x00007f792ac222d0 in KMMainWidget::slotMarkAll() () from /usr/lib/libkmailprivate.so.4
#9  0x00007f792ac2366c in KMMainWidget::slotEmptyFolder() () from /usr/lib/libkmailprivate.so.4
#10 0x00007f792ac2927d in KMMainWidget::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#11 0x00007f7947026b1a in QMetaObject::activate (sender=0x1971490, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff06859090) at kernel/qobject.cpp:3278
#12 0x00007f7947a2d3e2 in QAction::triggered (this=<value optimized out>, _t1=false) at .moc/release-shared/moc_qaction.cpp:263
#13 0x00007f7947a2d5cf in QAction::activate (this=0x1971490, event=<value optimized out>) at kernel/qaction.cpp:1257
#14 0x00007f7947e600f9 in QMenuPrivate::activateCausedStack (this=0x40260e0, causedStack=..., action=0x1971490, action_e=QAction::Trigger, self=true) at widgets/qmenu.cpp:993
#15 0x00007f7947e65d32 in QMenuPrivate::activateAction (this=0x40260e0, action=0x1971490, action_e=QAction::Trigger, self=true) at widgets/qmenu.cpp:1085
#16 0x00007f794882712d in KMenu::mouseReleaseEvent (this=0x4084740, e=<value optimized out>) at ../../kdeui/widgets/kmenu.cpp:458
#17 0x00007f7947a84016 in QWidget::event (this=0x4084740, event=0x7fff06859dd0) at kernel/qwidget.cpp:8259
#18 0x00007f7947e6729b in QMenu::event (this=0x4084740, e=0x7fff06859dd0) at widgets/qmenu.cpp:2415
#19 0x00007f7947a339f4 in notify_helper (this=0xea8c50, receiver=0x4084740, e=0x7fff06859dd0) at kernel/qapplication.cpp:4467
#20 QApplicationPrivate::notify_helper (this=0xea8c50, receiver=0x4084740, e=0x7fff06859dd0) at kernel/qapplication.cpp:4439
#21 0x00007f7947a3917b in QApplication::notify (this=<value optimized out>, receiver=0x4084740, e=0x7fff06859dd0) at kernel/qapplication.cpp:4028
#22 0x00007f7948760a66 in KApplication::notify (this=0x7fff0685c240, receiver=0x4084740, event=0x7fff06859dd0) at ../../kdeui/kernel/kapplication.cpp:311
#23 0x00007f7947013fbc in QCoreApplication::notifyInternal (this=0x7fff0685c240, receiver=0x4084740, event=0x7fff06859dd0) at kernel/qcoreapplication.cpp:731
#24 0x00007f7947a349c2 in sendEvent (receiver=0x4084740, event=0x7fff06859dd0, alienWidget=0x0, nativeWidget=0x4084740, buttonDown=0x0, lastMouseReceiver=..., spontaneous=true) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#25 QApplicationPrivate::sendMouseEvent (receiver=0x4084740, event=0x7fff06859dd0, alienWidget=0x0, nativeWidget=0x4084740, buttonDown=0x0, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:3127
#26 0x00007f7947ab1464 in QETWidget::translateMouseEvent (this=0x4084740, event=<value optimized out>) at kernel/qapplication_x11.cpp:4399
#27 0x00007f7947aafbea in QApplication::x11ProcessEvent (this=0x7fff0685c240, event=0x7fff0685a4f0) at kernel/qapplication_x11.cpp:3591
#28 0x00007f7947ad7d32 in x11EventSourceDispatch (s=0xeb8750, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#29 0x00007f79402c309d in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#30 0x00007f79402c3878 in ?? () from /lib/libglib-2.0.so.0
#31 0x00007f79402c3b09 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#32 0x00007f794703eabf in QEventDispatcherGlib::processEvents (this=0xe78610, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#33 0x00007f7947ad79ce in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#34 0x00007f79470131c2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#35 0x00007f79470133bf in QEventLoop::exec (this=0x7fff0685a8b0, flags=...) at kernel/qeventloop.cpp:201
#36 0x00007f7947e63211 in QMenu::exec (this=<value optimized out>, p=..., action=0x0) at widgets/qmenu.cpp:2059
#37 0x00007f792aa0b6da in KMail::FolderView::contextMenuEvent(QContextMenuEvent*) () from /usr/lib/libkmailprivate.so.4
#38 0x00007f7947a83d70 in QWidget::event (this=0x1948330, event=0x7fff0685b720) at kernel/qwidget.cpp:8426
#39 0x00007f7947e25066 in QFrame::event (this=0x1948330, e=0x7fff0685b720) at widgets/qframe.cpp:557
#40 0x00007f7947f350cb in QAbstractItemView::viewportEvent (this=0x1948330, event=0x7fff0685b720) at itemviews/qabstractitemview.cpp:1628
#41 0x00007f7947f79df5 in QTreeView::viewportEvent (this=0x1948330, event=0x7fff0685b720) at itemviews/qtreeview.cpp:1256
#42 0x00007f7947014148 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x1519460, event=0x7fff0685b720) at kernel/qcoreapplication.cpp:846
#43 0x00007f7947a339bf in notify_helper (this=0xea8c50, receiver=0x1519460, e=0x7fff0685b720) at kernel/qapplication.cpp:4463
#44 QApplicationPrivate::notify_helper (this=0xea8c50, receiver=0x1519460, e=0x7fff0685b720) at kernel/qapplication.cpp:4439
#45 0x00007f7947a38d6c in QApplication::notify (this=<value optimized out>, receiver=0x1519460, e=0x7fff0685b720) at kernel/qapplication.cpp:4107
#46 0x00007f7948760a66 in KApplication::notify (this=0x7fff0685c240, receiver=0x1519460, event=0x7fff0685b720) at ../../kdeui/kernel/kapplication.cpp:311
#47 0x00007f7947013fbc in QCoreApplication::notifyInternal (this=0x7fff0685c240, receiver=0x1519460, event=0x7fff0685b720) at kernel/qcoreapplication.cpp:731
#48 0x00007f7947ab0e4b in sendSpontaneousEvent (this=<value optimized out>, event=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#49 QETWidget::translateMouseEvent (this=<value optimized out>, event=<value optimized out>) at kernel/qapplication_x11.cpp:4470
#50 0x00007f7947aafbea in QApplication::x11ProcessEvent (this=0x7fff0685c240, event=0x7fff0685be10) at kernel/qapplication_x11.cpp:3591
#51 0x00007f7947ad7d32 in x11EventSourceDispatch (s=0xeb8750, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#52 0x00007f79402c309d in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#53 0x00007f79402c3878 in ?? () from /lib/libglib-2.0.so.0
#54 0x00007f79402c3b09 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#55 0x00007f794703eabf in QEventDispatcherGlib::processEvents (this=0xe78610, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#56 0x00007f7947ad79ce in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#57 0x00007f79470131c2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#58 0x00007f79470133bf in QEventLoop::exec (this=0x7fff0685c1d0, flags=...) at kernel/qeventloop.cpp:201
#59 0x00007f7947017567 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#60 0x00000000004038ac in ?? ()
#61 0x00007f7946832ead in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fff0685c818) at libc-start.c:228
#62 0x0000000000403df1 in _start ()

Reported using DrKonqi