Application: kmail (1.13.6)
KDE Platform Version: 4.6.00 (4.6.0) "release 6"
Qt Version: 4.7.1
Operating System: Linux 2.6.37.1-1.2-default i686
Distribution: "openSUSE 11.4 (i586)"

-- Information about the crash:
- What I was doing when the application crashed: 
(1) I was working on a mail containing 2 attachments - each about 300 to 400 kB 
(2) I stored the 2 attachments one after another   in a directory
(3) Then I started removing the attachments. If I recall well, kmail crashed when I tried to remove the second attachment.

Additional remarks:
 -  I've been doing some housekeeping in my kmail database today. In the course of this action, kmail has crashed at least 3 times in the 
   same way while I was working on (different ) mails containing more than 1 attachment.
 - After starting kmail anew, there were 2 mails of the same title in the directory (or folder) where I was working in the moment of the
  crash. One contains the text of the mail, the attachment is marked as removed and the size is small as expected. The other one is empty, but
  appears with the full size in the folder list.
 - My Linux distribution is SuSE 11.4.
    I have observed the same behaviour with earlier versions of SuSE and KDE during the last two (?) years.

The crash can be reproduced every time.

-- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[Current thread is 1 (Thread 0xb2136710 (LWP 3730))]

Thread 2 (Thread 0xae13ab70 (LWP 3836)):
#0  0xb5422fcd in pthread_mutex_lock () from /lib/libpthread.so.0
#1  0xb598cd04 in pthread_mutex_lock () from /lib/libc.so.6
#2  0xb3c361af in g_main_context_check () from /lib/libglib-2.0.so.0
#3  0xb3c36ac8 in ?? () from /lib/libglib-2.0.so.0
#4  0xb3c36fce in g_main_context_iteration () from /lib/libglib-2.0.so.0
#5  0xb5cb57b7 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#6  0xb5c862bd in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#7  0xb5c864e9 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#8  0xb5b877b9 in QThread::exec() () from /usr/lib/libQtCore.so.4
#9  0xb5c6623d in ?? () from /usr/lib/libQtCore.so.4
#10 0xb5b8a3aa in ?? () from /usr/lib/libQtCore.so.4
#11 0xb5420b05 in start_thread () from /lib/libpthread.so.0
#12 0xb597ed5e in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb2136710 (LWP 3730)):
[KCrash Handler]
#7  0xb6d83779 in KMTrashMsgCommand::KMTrashMsgCommand(unsigned int) () from /usr/lib/libkmailprivate.so.4
#8  0xb6d83a16 in AttachmentModifyCommand::messageStoreResult(KMFolderImap*, bool) () from /usr/lib/libkmailprivate.so.4
#9  0xb6d83d0d in AttachmentModifyCommand::storeChangedMessage(KMMessage*) () from /usr/lib/libkmailprivate.so.4
#10 0xb6d84389 in KMDeleteAttachmentCommand::doAttachmentModify() () from /usr/lib/libkmailprivate.so.4
#11 0xb6d6bfa5 in AttachmentModifyCommand::execute() () from /usr/lib/libkmailprivate.so.4
#12 0xb6d7be4a in KMCommand::slotPostTransfer(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#13 0xb6d8778d in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#14 0xb6d885e2 in AttachmentModifyCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#15 0xb6d88693 in KMDeleteAttachmentCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#16 0xb5c8d8cd in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#17 0xb5c9da2c in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#18 0xb6d72d45 in KMCommand::messagesTransfered(KMCommand::Result) () from /usr/lib/libkmailprivate.so.4
#19 0xb6d7ba2e in KMCommand::transferSelectedMsgs() () from /usr/lib/libkmailprivate.so.4
#20 0xb6d7bc66 in KMCommand::slotStart() () from /usr/lib/libkmailprivate.so.4
#21 0xb6d8776c in KMCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#22 0xb6d885e2 in AttachmentModifyCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#23 0xb6d88693 in KMDeleteAttachmentCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#24 0xb5c8d8cd in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#25 0xb5c983a5 in QMetaCallEvent::placeMetaCall(QObject*) () from /usr/lib/libQtCore.so.4
#26 0xb5c9c5af in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#27 0xb5f02414 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#28 0xb5f0b0c7 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#29 0xb74c91f1 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#30 0xb5c86fde in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#31 0xb5c8ad6c in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQtCore.so.4
#32 0xb5c8aebc in QCoreApplication::sendPostedEvents(QObject*, int) () from /usr/lib/libQtCore.so.4
#33 0xb5cb55e4 in ?? () from /usr/lib/libQtCore.so.4
#34 0xb3c36509 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#35 0xb3c36d10 in ?? () from /lib/libglib-2.0.so.0
#36 0xb3c36fce in g_main_context_iteration () from /lib/libglib-2.0.so.0
#37 0xb5cb576b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#38 0xb5fb855a in ?? () from /usr/lib/libQtGui.so.4
#39 0xb5c862bd in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#40 0xb5c864e9 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#41 0xb5c8af90 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#42 0xb5f00104 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#43 0x0804aa83 in _start ()

Reported using DrKonqi