Application that crashed: kontact
Version of the application: 4.3.4
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-16-generic-pae i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
Kmail crash when I open email in a research.
Notice that the email that is to be open is located in a virtual folder came from a Thunderbird import.
This bug is reproducable.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  QString (this=0xf9609d8, s=..., number=false) at ../../include/QtCore/../../src/corelib/tools/qstring.h:711
#7  QTextStreamPrivate::putString (this=0xf9609d8, s=..., number=false) at io/qtextstream.cpp:933
#8  0xb65b518b in QTextStream::operator<< (this=0xc9238c0, string=...) at io/qtextstream.cpp:2511
#9  0xb0b7f198 in QDebug::operator<< (this=0xaee4318, it=0x0) at /usr/include/qt4/QtCore/qdebug.h:108
#10 KMail::MessageListView::Core::View::setCurrentMessageItem (this=0xaee4318, it=0x0) at ../../kmail/messagelistview/core/view.cpp:768
#11 0xb0b28b24 in KMail::MessageListView::Widget::activateMessageItemByMsgBase (this=0xaf37c00, msg=0xedae460) at ../../kmail/messagelistview/widget.cpp:276
#12 0xb0b1effb in KMail::MessageListView::Pane::activateMessage (this=0xa732ad8, msg=0xedae460) at ../../kmail/messagelistview/pane.cpp:604
#13 0xb09c115a in KMMainWidget::slotSelectMessage (this=0xa5107b0, msg=0xedae460) at ../../kmail/kmmainwidget.cpp:3150
#14 0xb0920a33 in KMail::SearchWindow::slotShowMsg (this=0xb9bec78, item=0xe7fb5e8) at ../../kmail/searchwindow.cpp:726
#15 0xb0920f6e in KMail::SearchWindow::qt_metacall (this=0xb9bec78, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbff2eee4) at ./searchwindow.moc:128
#16 0xb6623263 in QMetaObject::activate (sender=0xc4c6d30, from_signal_index=96, to_signal_index=96, argv=0xbff2eee4) at kernel/qobject.cpp:3113
#17 0xb6623ec2 in QMetaObject::activate (sender=0xc4c6d30, m=0xb72dd930, local_signal_index=1, argv=0xbff2eee4) at kernel/qobject.cpp:3187
#18 0xb7034d29 in QTreeWidget::itemClicked (this=0xc4c6d30, _t1=0xe7fb5e8, _t2=0) at .moc/release-shared/moc_qtreewidget.cpp:201
#19 0xb7039b22 in QTreeWidgetPrivate::_q_emitItemClicked (this=0xc3b28f8, index=...) at itemviews/qtreewidget.cpp:2228
#20 0xb7041791 in QTreeWidget::qt_metacall (this=0xc4c6d30, _c=QMetaObject::InvokeMetaMethod, _id=16, _a=0xbff2f078) at .moc/release-shared/moc_qtreewidget.cpp:144
#21 0xb091f03a in KMail::MatchListView::qt_metacall (this=0xc4c6d30, _c=QMetaObject::InvokeMetaMethod, _id=111, _a=0xbff2f078) at ./searchwindow.moc:203
#22 0xb6623263 in QMetaObject::activate (sender=0xc4c6d30, from_signal_index=32, to_signal_index=32, argv=0xbff2f078) at kernel/qobject.cpp:3113
#23 0xb6623ec2 in QMetaObject::activate (sender=0xc4c6d30, m=0xb72dc884, local_signal_index=1, argv=0xbff2f078) at kernel/qobject.cpp:3187
#24 0xb6fb5053 in QAbstractItemView::clicked (this=0xc4c6d30, _t1=...) at .moc/release-shared/moc_qabstractitemview.cpp:321
#25 0xb6fc2efa in QAbstractItemView::mouseReleaseEvent (this=0xc4c6d30, event=0xbff2f9b0) at itemviews/qabstractitemview.cpp:1660
#26 0xb700730c in QTreeView::mouseReleaseEvent (this=0xc4c6d30, event=0xbff2f9b0) at itemviews/qtreeview.cpp:1796
#27 0xb6ac4012 in QWidget::event (this=0xc4c6d30, event=0xbff2f9b0) at kernel/qwidget.cpp:7549
#28 0xb6e73633 in QFrame::event (this=0xc4c6d30, e=0xbff2f9b0) at widgets/qframe.cpp:559
#29 0xb6f12494 in QAbstractScrollArea::viewportEvent (this=0x0, e=0x0) at widgets/qabstractscrollarea.cpp:962
#30 0xb6fc6087 in QAbstractItemView::viewportEvent (this=0xc4c6d30, event=0xbff2f9b0) at itemviews/qabstractitemview.cpp:1476
#31 0xb7001434 in QTreeView::viewportEvent (this=0xc4c6d30, event=0xbff2f9b0) at itemviews/qtreeview.cpp:1266
#32 0xb6f14a95 in QAbstractScrollAreaPrivate::viewportEvent (this=0xc0aa0a0, o=0xc45a240, e=0xbff2f9b0) at widgets/qabstractscrollarea_p.h:100
#33 QAbstractScrollAreaFilter::eventFilter (this=0xc0aa0a0, o=0xc45a240, e=0xbff2f9b0) at widgets/qabstractscrollarea_p.h:111
#34 0xb660c83a in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x9f87ad0, receiver=0xc45a240, event=0xbff2f9b0) at kernel/qcoreapplication.cpp:726
#35 0xb6a6ef2c in QApplicationPrivate::notify_helper (this=0x9f87ad0, receiver=0xc45a240, e=0xbff2f9b0) at kernel/qapplication.cpp:4052
#36 0xb6a77033 in QApplication::notify (this=0xbff31394, receiver=0xc45a240, e=0xbff2f9b0) at kernel/qapplication.cpp:3758
#37 0xb74bf1aa in KApplication::notify (this=0xbff31394, receiver=0xc45a240, event=0xbff2f9b0) at ../../kdeui/kernel/kapplication.cpp:302
#38 0xb660d6cb in QCoreApplication::notifyInternal (this=0xbff31394, receiver=0xc45a240, event=0xbff2f9b0) at kernel/qcoreapplication.cpp:610
#39 0xb6a75f6e in QCoreApplication::sendSpontaneousEvent (receiver=0xc45a240, event=0xbff2f9b0, alienWidget=0xc45a240, nativeWidget=0xb9bec78, buttonDown=0xb72e9aa0, lastMouseReceiver=...)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#40 QApplicationPrivate::sendMouseEvent (receiver=0xc45a240, event=0xbff2f9b0, alienWidget=0xc45a240, nativeWidget=0xb9bec78, buttonDown=0xb72e9aa0, lastMouseReceiver=...)
    at kernel/qapplication.cpp:2924
#41 0xb6ae47c0 in QETWidget::translateMouseEvent (this=0xb9bec78, event=0xbff30ffc) at kernel/qapplication_x11.cpp:4409
#42 0xb6ae3c4b in QApplication::x11ProcessEvent (this=0xbff31394, event=0xbff30ffc) at kernel/qapplication_x11.cpp:3428
#43 0xb6b10502 in x11EventSourceDispatch (s=0x9f91800, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#44 0xb4935e88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#45 0xb4939730 in ?? () from /lib/libglib-2.0.so.0
#46 0xb4939863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#47 0xb663802c in QEventDispatcherGlib::processEvents (this=0x9f689f8, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#48 0xb6b0fbe5 in QGuiEventDispatcherGlib::processEvents (this=0x9f689f8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#49 0xb660bc79 in QEventLoop::processEvents (this=0xbff312f4, flags=) at kernel/qeventloop.cpp:149
#50 0xb660c0ca in QEventLoop::exec (this=0xbff312f4, flags=...) at kernel/qeventloop.cpp:201
#51 0xb660e53f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#52 0xb6a6edd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#53 0x0804b4e6 in main (argc=1, argv=0xbff315b4) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi