Created attachment 19375 [details]
backtrace of the crash

the binary and coredump file of this crash is available on:
http://chainsword.homeip.net/kmail_core.tar.bz2

Can you isolate the file that is causing the crash? Does the crash still occur if you remove all the "*index*" files? (should be harmless, but back up your mail dir before you delete anything in it :-)

Yes, removing the *index* files helped, after that kmail operates normaly :] 
I will try to further isolate the problem, what data is causing the crash,
although odd it seems to me that bad data in the index files is causing the crash ( ?lazy coding? ).

Pasting backtrace for easier searching:

#5  0xb6edb521 in fileno_unlocked () from /lib/libc.so.6
#6  0xb7d9cfc8 in KMFolderIndex::writeIndex (this=0x8151550, 
    createEmptyIndex=false)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfolderindex.cpp:202
#7  0xb7ce5ad3 in KMFolderMaildir::createIndexFromContents (this=0x8151550)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfoldermaildir.cpp:893
#8  0xb7ce1a4c in KMFolderMaildir::open (this=0x8151550)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfoldermaildir.cpp:140
#9  0xb7c108c7 in KMFolder::open (this=0x81513d8)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfolder.cpp:473
#10 0xb7be43f9 in KMHeaders::setFolder (this=0x818d7d8, aFolder=0x81513d8, 
    forceJumpToUnread=false)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmheaders.cpp:713
#11 0xb7d89a85 in KMMainWidget::folderSelected (this=0x81768d0, 
    aFolder=0x81513d8, forceJumpToUnread=<value optimized out>)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmmainwidget.cpp:1869
#12 0xb7d958c7 in KMMainWidget::qt_invoke (this=0x81768d0, _id=51, 
    _o=0xbfa1ef94) at /usr/src/debug/kdepim-3.5.5/kmail/kmmainwidget.moc:477
#13 0xb7303331 in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#14 0xb7bbbb3e in KMFolderTree::folderSelected (this=0x821b008, t0=0x81513d8)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfoldertree.moc:384
#15 0xb7bbd262 in KMFolderTree::doFolderSelected (this=0x821b008, 
    qlvi=0x827f898) at /usr/src/debug/kdepim-3.5.5/kmail/kmfoldertree.cpp:932
#16 0xb7bbd305 in KMFolderTree::showFolder (this=0x821b008, folder=0x81513d8)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmfoldertree.cpp:1733
#17 0xb7d88ebb in KMMainWidget::slotShowStartupFolder (this=0x81768d0)
    at /usr/src/debug/kdepim-3.5.5/kmail/kmmainwidget.cpp:3215
#18 0xb7d96295 in KMMainWidget::qt_invoke (this=0x81768d0, _id=153, 
    _o=0xbfa1f0f4) at /usr/src/debug/kdepim-3.5.5/kmail/kmmainwidget.moc:579
#19 0xb73033cd in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#20 0xb763d0ce in QSignal::signal () from /usr/lib/qt3/lib/libqt-mt.so.3
#21 0xb731f497 in QSignal::activate () from /usr/lib/qt3/lib/libqt-mt.so.3
#22 0xb7326823 in QSingleShotTimer::event ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#23 0xb72a4647 in QApplication::internalNotify ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#24 0xb72a54f9 in QApplication::notify () from /usr/lib/qt3/lib/libqt-mt.so.3
#25 0xb79611f2 in KApplication::notify () from /opt/kde3/lib/libkdecore.so.4
#26 0xb7299663 in QEventLoop::activateTimers ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#27 0xb7253bd0 in QEventLoop::processEvents ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#28 0xb72bb0e0 in QEventLoop::enterLoop () from /usr/lib/qt3/lib/libqt-mt.so.3
#29 0xb72baf76 in QEventLoop::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#30 0xb72a400f in QApplication::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#31 0x0804a0eb in main (argc=1219996, argv=0xb70902a0)
    at /usr/src/debug/kdepim-3.5.5/kmail/main.cpp:110
#32 0xb6e93f9c in __libc_start_main () from /lib/libc.so.6
#33 0x08049e61 in _start ()

*** Bug 150752 has been marked as a duplicate of this bug. ***

*** Bug 161457 has been marked as a duplicate of this bug. ***

Created attachment 27227 [details]
patch of kmail/cifs bug

Bug 161457 has been marked as a duplicate of this bug, but I think it has not the same reason. Bug 161457 is actually related to the cifs bug 5431 "rename fails when newpath is open and deletes newpath". Cifs does not rename an open file but deletes it instead. The kmail part of the bug is that kmail does not check for errors after trying to rename an open file and crashes when trying to continue to work with the deleted file. This happens in kmail/kmfolderindex.cpp at line 192. Wilhelm Maier (wilhelm.meier@fh-kl.de) provided a simple patch for kmail that solves bug 161457 (see attachment).

bug #161457 is about the inability of kmail to cope with read-only mailboxes. So it is indeed another bug.

Concerning this bug: Is this still valid in KDE 4.3 or later?

No response. Closing old KDE 3 crash.