Version:           1.13.5 (using KDE 4.5.5) 
OS:                Linux

KMail crashed on deleting a message from an IMAP folder. There probably were other jobs executing in the background (as in, other thing KMail was doing, like polling messages from some account, sending messages, filtering messages...), but I don't know exactly which.
This happened shortly after program startup. I was manually deleting some spams at that moment.

Reproducible: Sometimes

Steps to Reproduce:
Delete a message from an IMAP folder while kmail is still doing something else or delete several mails from IMAP folders in very quick succession.

Actual Results:  
KMail crashed with a segfault

Expected Results:  
The message(s) on the IMAP folder gets deleted shortly after and KMail keeps running.

Backtrace:

Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#6  QList (this=0x49553b2f79614245) at /usr/include/qt4/QtCore/qlist.h:114
#7  KMail::FolderJob::msgList (this=0x49553b2f79614245) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/folderjob.cpp:120
#8  0x00007f1acf2b363b in KMAcctImap::ignoreJobsForMessage (this=0x30c19e0, msg=0x3b6a5f0) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/kmacctimap.cpp:217
#9  0x00007f1acf3b76c7 in KMMoveCommand::execute (this=0x4398320) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/kmcommands.cpp:2208
#10 0x00007f1acf3ab42a in KMCommand::slotPostTransfer (this=0x4398320, result=KMCommand::OK) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/kmcommands.cpp:295
#11 0x00007f1acf3b2733 in KMCommand::qt_metacall (this=0x4398320, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc1a35c20) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8_build/kmail/kmcommands.moc:93
#12 0x00007f1acf3b6fe0 in KMMoveCommand::qt_metacall (this=0x4398320, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc1a35c20) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8_build/kmail/kmcommands.moc:1971
#13 0x00007f1acdcd9c76 in QMetaObject::activate (sender=0x4398320, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x258a0) at kernel/qobject.cpp:3287
#14 0x00007f1acf3a33ce in KMCommand::messagesTransfered (this=<value optimized out>, _t1=KMCommand::OK) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8_build/kmail/kmcommands.moc:108
#15 0x00007f1acf3ab1ec in KMCommand::transferSelectedMsgs (this=0x4398320) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/kmcommands.cpp:393
#16 0x00007f1acf3af468 in KMCommand::slotStart (this=0x4398320) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/kmcommands.cpp:287
#17 0x00007f1acf3b2716 in KMCommand::qt_metacall (this=0x4398320, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc1a35e80) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8_build/kmail/kmcommands.moc:92
#18 0x00007f1acf3b6fe0 in KMMoveCommand::qt_metacall (this=0x4398320, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc1a35e80) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8_build/kmail/kmcommands.moc:1971
#19 0x00007f1acdcd9c76 in QMetaObject::activate (sender=0x42e0810, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x258a0) at kernel/qobject.cpp:3287
#20 0x00007f1acdce10df in QSingleShotTimer::timerEvent (this=0x42e0810) at kernel/qtimer.cpp:308
#21 0x00007f1acdcd6503 in QObject::event (this=0x42e0810, e=0x7fffc1a365e0) at kernel/qobject.cpp:1204
#22 0x00007f1ace19a94c in QApplicationPrivate::notify_helper (this=0x218ca30, receiver=0x42e0810, e=0x7fffc1a365e0) at kernel/qapplication.cpp:4302
#23 0x00007f1ace1a0e1b in QApplication::notify (this=0x7fffc1a36a30, receiver=0x42e0810, e=0x7fffc1a365e0) at kernel/qapplication.cpp:4185
#24 0x00007f1ad01f2346 in KApplication::notify (this=0x7fffc1a36a30, receiver=0x42e0810, event=0x7fffc1a365e0) at /var/tmp/portage/kde-base/kdelibs-4.5.5/work/kdelibs-4.5.5/kdeui/kernel/kapplication.cpp:310
#25 0x00007f1acdcc6a8c in QCoreApplication::notifyInternal (this=0x7fffc1a36a30, receiver=0x42e0810, event=0x7fffc1a365e0) at kernel/qcoreapplication.cpp:726
#26 0x00007f1acdcf37d2 in sendEvent (this=0x21902e0) at kernel/qcoreapplication.h:215
#27 QTimerInfoList::activateTimers (this=0x21902e0) at kernel/qeventdispatcher_unix.cpp:603
#28 0x00007f1acdcf0314 in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#29 0x00007f1ac5356233 in g_main_dispatch (context=0x218f120) at gmain.c:1960
#30 IA__g_main_context_dispatch (context=0x218f120) at gmain.c:2513
#31 0x00007f1ac5356a10 in g_main_context_iterate (context=0x218f120, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2591
#32 0x00007f1ac5356cad in IA__g_main_context_iteration (context=0x218f120, may_block=1) at gmain.c:2654
#33 0x00007f1acdcf0003 in QEventDispatcherGlib::processEvents (this=0x214b840, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:412
#34 0x00007f1ace24938e in QGuiEventDispatcherGlib::processEvents (this=0x7fffc1a35840, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#35 0x00007f1acdcc53b2 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#36 0x00007f1acdcc578c in QEventLoop::exec (this=0x7fffc1a36860, flags=) at kernel/qeventloop.cpp:201
#37 0x00007f1acdcca41b in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1003
#38 0x0000000000403688 in main (argc=<value optimized out>, argv=<value optimized out>) at /var/tmp/portage/kde-base/kmail-4.4.8/work/kmail-4.4.8/kmail/main.cpp:156