Bug 92540

Today when I got the freeze again, and attached gdb to it, I got the same backtrace except for the last line, and it showed that it was looping on line 1295 of qlistview.cpp instead:
    while( nextChild && *nextChild && item != *nextChild )
        nextChild = &((*nextChild)->siblingItem);
and it was looping between 3 items.

If I remember correctly, I first removed the first message in a thread, and when trying to delete the second one it froze, but I'm not entirely sure.

Haven't seen this one in a while, closing.

I'm seeing this bug in 3.4.0, could you please reopen?

It happened also in previous versions (both kmail standalone and in kontact), and is not easily reproduceable.
The backtrace I get is the same:

#0  0xb6a4dac0 in QListViewItem::takeItem(QListViewItem*) ()
   from /usr/qt/3/lib/libqt-mt.so.3
#1  0xb6a4d394 in QListViewItem::~QListViewItem() () from /usr/qt/3/lib/libqt-mt.so.3
#2  0xb7261461 in KListViewItem::~KListViewItem() () from /usr/kde/3.4/lib/libkdeui.so.4
#3  0xb5a8a893 in KMail::HeaderItem::~HeaderItem() ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#4  0xb5a7e9af in KMHeaders::msgRemoved(int, QString) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#5  0xb5a88fa6 in KMHeaders::qt_invoke(int, QUObject*) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#6  0xb69794b5 in QObject::activate_signal(QConnectionList*, QUObject*) ()
   from /usr/qt/3/lib/libqt-mt.so.3
#7  0xb5abe5bb in KMFolder::msgRemoved(int, QString) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#8  0xb5abed19 in KMFolder::qt_emit(int, QUObject*) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#9  0xb69794ed in QObject::activate_signal(QConnectionList*, QUObject*) ()
   from /usr/qt/3/lib/libqt-mt.so.3
#10 0xb5ad8d5f in FolderStorage::msgRemoved(int, QString) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#11 0xb5ad5eff in FolderStorage::take(int) () from /usr/kde/3.4/lib/libkmailprivate.so
#12 0xb5b74ea2 in KMFolderMaildir::take(int) () from /usr/kde/3.4/lib/libkmailprivate.so
#13 0xb5abc777 in KMFolder::take(int) () from /usr/kde/3.4/lib/libkmailprivate.so
#14 0xb5b71bb9 in KMFolderMaildir::addMsgInternal(KMMessage*, int*, bool) ()
   from /usr/kde/3.4/lib/libkmailprivate.so
#15 0xb5b71612 in KMFolderMaildir::addMsg(KMMessage*, int*) ()


It seems to occur in the following situation (it's a necessary but not sufficient condition, though):

message A is parent of message B in a thread, but B is not a reply to A: they are both replies to the same old message and got threaded together.
Delete A, B gets focus, and kmail freezes.

Reported in 3.4. Reopen.

This happened again with kdepim 3.5-branch from around rc1.

It got stuck this time too in QListView::itemAbove, where it was stuck in:
         while( c && c->siblingItem != this )
             c = c->siblingItem;
because c was the same as c->siblingItem.

So I added asserts in qlistview.cpp everywhere where siblingItem was assigned to something, to check if there were any assignments of the kind item->siblingItem = item

And the assert was triggered when trying to delete the same message again with this backtrace:

Using host libthread_db library "/lib/tls/libthread_db.so.1".
`system-supplied DSO at 0xffffe000' has disappeared; keeping its symbols.
[Thread debugging using libthread_db enabled]
[New Thread -1252845856 (LWP 15531)]
[KCrash handler]
#4  0xffffe410 in __kernel_vsyscall ()
#5  0xb5d96391 in raise () from /lib/tls/libc.so.6
#6  0xb5d97dad in abort () from /lib/tls/libc.so.6
#7  0xb5d8fc62 in __assert_fail () from /lib/tls/libc.so.6
#8  0xb6615fe8 in QListViewItem::insertItem (this=0x857a5a8, 
    newChild=0x85940e0) at qlistview.cpp:1176
#9  0xb661ba30 in QListView::insertItem (this=0x8577de0, i=0x85940e0)
    at qlistview.cpp:3203
#10 0xb4dc5117 in KMHeaders::msgRemoved (this=0x8577de0, id=2, msgId=
      {static null = {static null = <same as static member of an already seen type>, d = 0x8074388, static shared_null = 0x8074388}, d = 0x853d408, static shared_null = 0x8074388})
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmheaders.cpp:1088
#11 0xb4dcf20d in KMHeaders::qt_invoke (this=0x8577de0, _id=112, _o=0xbf9cdfb0)
    at kmheaders.moc:301
#12 0xb652ac1f in QObject::activate_signal (this=0x853ced8, clist=0x86a2490, 
    o=0xbf9cdfb0) at qobject.cpp:2356
#13 0xb4e01685 in KMFolder::msgRemoved (this=0x853ced8, t0=2, t1=
      {static null = {static null = <same as static member of an already seen type>, d = 0x8074388, static shared_null = 0x8074388}, d = 0x853d408, static shared_null = 0x8074388}) at kmfolder.moc:254
#14 0xb4e02047 in KMFolder::qt_emit (this=0x853ced8, _id=9, _o=0xbf9ce0d0)
    at kmfolder.moc:381
#15 0xb652abf3 in QObject::activate_signal (this=0x853cfe0, clist=0x853d740, 
    o=0xbf9ce0d0) at qobject.cpp:2354
#16 0xb4e1e745 in FolderStorage::msgRemoved (this=0x853cfe0, t0=2, t1=
      {static null = {static null = <same as static member of an already seen type>, d = 0x8074388, static shared_null = 0x8074388}, d = 0x853d408, static shared_null = 0x8074388}) at folderstorage.moc:320
#17 0xb4e1b283 in FolderStorage::take (this=0x853cfe0, idx=2)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/folderstorage.cpp:441
#18 0xb4ecdd3c in KMFolderMaildir::take (this=0x853cfe0, idx=2)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmfoldermaildir.cpp:941
#19 0xb4dff93e in KMFolder::take (this=0x853ced8, idx=2)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmfolder.cpp:364
#20 0xb4ecb2a9 in KMFolderMaildir::addMsgInternal (this=0x851d040, 
    aMsg=0x8627720, index_return=0xbf9ce450, stripUid=false)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmfoldermaildir.cpp:453
#21 0xb4ecab75 in KMFolderMaildir::addMsg (this=0x851d040, aMsg=0x8627720, 
    index_return=0xbf9ce450)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmfoldermaildir.cpp:365
#22 0xb4e1baab in FolderStorage::moveMsg (this=0x851d040, aMsg=0x8627720, 
    aIndex_ret=0xbf9ce450)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/folderstorage.cpp:590
#23 0xb4dffb25 in KMFolder::moveMsg (this=0x851cf38, msg=0x8627720, 
    index_return=0xbf9ce450)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmfolder.cpp:409
#24 0xb4f4def0 in KMMoveCommand::execute (this=0x87c8970)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmcommands.cpp:1924
#25 0xb4f45468 in KMCommand::slotPostTransfer (this=0x87c8970, 
    result=KMCommand::OK)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmcommands.cpp:254
#26 0xb4f555b3 in KMCommand::qt_invoke (this=0x87c8970, _id=5, _o=0xbf9ce620)
    at kmcommands.moc:148
#27 0xb4f5922f in KMMenuCommand::qt_invoke (this=0x87c8970, _id=5, 
    _o=0xbf9ce620) at kmcommands.moc:2436
#28 0xb4f59771 in KMMoveCommand::qt_invoke (this=0x87c8970, _id=5, 
    _o=0xbf9ce620) at kmcommands.moc:2619
#29 0xb4f59967 in KMDeleteMsgCommand::qt_invoke (this=0x87c8970, _id=5, 
    _o=0xbf9ce620) at kmcommands.moc:2694
#30 0xb652ac1f in QObject::activate_signal (this=0x87c8970, clist=0x874a8c8, 
    o=0xbf9ce620) at qobject.cpp:2356
#31 0xb4f553b9 in KMCommand::messagesTransfered (this=0x87c8970, 
    t0=KMCommand::OK) at kmcommands.moc:126
#32 0xb4f459b3 in KMCommand::transferSelectedMsgs (this=0x87c8970)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmcommands.cpp:349
#33 0xb4f45411 in KMCommand::slotStart (this=0x87c8970)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kmail/kmcommands.cpp:246
#34 0xb4f55583 in KMCommand::qt_invoke (this=0x87c8970, _id=4, _o=0xbf9ce830)
    at kmcommands.moc:147
#35 0xb4f5922f in KMMenuCommand::qt_invoke (this=0x87c8970, _id=4, 
    _o=0xbf9ce830) at kmcommands.moc:2436
#36 0xb4f59771 in KMMoveCommand::qt_invoke (this=0x87c8970, _id=4, 
    _o=0xbf9ce830) at kmcommands.moc:2619
#37 0xb4f59967 in KMDeleteMsgCommand::qt_invoke (this=0x87c8970, _id=4, 
    _o=0xbf9ce830) at kmcommands.moc:2694
#38 0xb652ac1f in QObject::activate_signal (this=0x827fbd8, clist=0x86c9848, 
    o=0xbf9ce830) at qobject.cpp:2356
#39 0xb6899517 in QSignal::signal (this=0x827fbd8, t0=@0x827fc00)
    at moc_qsignal.cpp:100
#40 0xb65489d2 in QSignal::activate (this=0x827fbd8) at qsignal.cpp:212
#41 0xb6550b34 in QSingleShotTimer::event (this=0x827fbb0) at qtimer.cpp:286
#42 0xb64c5ae9 in QApplication::internalNotify (this=0xbf9ceda0, 
    receiver=0x827fbb0, e=0xbf9ceaf0) at qapplication.cpp:2635
#43 0xb64c502a in QApplication::notify (this=0xbf9ceda0, receiver=0x827fbb0, 
    e=0xbf9ceaf0) at qapplication.cpp:2358
#44 0xb6bccd20 in KApplication::notify (this=0xbf9ceda0, receiver=0x827fbb0, 
    event=0xbf9ceaf0)
    at /home/richard/kde-svn/svn/trunk/KDE/kdelibs/kdecore/kapplication.cpp:550
#45 0xb7848432 in QApplication::sendEvent (receiver=0x827fbb0, 
    event=0xbf9ceaf0) at qapplication.h:496
#46 0xb64b3e3c in QEventLoop::activateTimers (this=0x81e6018)
    at qeventloop_unix.cpp:556
#47 0xb6469fec in QEventLoop::processEvents (this=0x81e6018, flags=4)
    at qeventloop_x11.cpp:389
#48 0xb64dadb3 in QEventLoop::enterLoop (this=0x81e6018) at qeventloop.cpp:198
#49 0xb64dacce in QEventLoop::exec (this=0x81e6018) at qeventloop.cpp:145
#50 0xb64c5c55 in QApplication::exec (this=0xbf9ceda0) at qapplication.cpp:2758
#51 0x0805cb91 in main (argc=1, argv=0xbf9cef74)
    at /home/richard/kde-svn/svn/trunk/KDE/kdepim/kontact/src/main.cpp:177
#52 0xb5d82f31 in __libc_start_main () from /lib/tls/libc.so.6
#53 0x0805bfe1 in _start ()

Line 1177 in qlistview.cpp is:
newChild->siblingItem = childItem;
and the assert was triggered because newChild was equal to childItem.

And around line 1088 in kmheaders.cpp is:
1084       if ( parent && parent->item() != item && parent->item() != removedItem ) {
1085         parent->item()->insertItem(lvi);
1086         parent->addSortedChild( sci );
1087       } else {
1088         insertItem(lvi);
1089         mRoot->addSortedChild( sci );
1090       }

So as far as I understand it, it tries to add an item to the root of the listview when it's already a child of the listview.

Also, looking at the thread I was trying to delete, the message I tried to delete was the parent of two messages when using "Thread messages also by Subject", but when unchecking subject-threading it was only the parent of one of them.

*** Bug 137144 has been marked as a duplicate of this bug. ***

The same bug just happened to me (KDE-3.5.5 in Debian testing). Here is the backtrace:

#0  0xb70e5d5b in QListViewItem::takeItem (this=0x849e578, item=0x84b6540) at widgets/qlistview.cpp:1323
        lv = (class QListView *) 0x849c3b8
        emit_changed = true
        nextChild = (QListViewItem **) 0x8634930
#1  0xb70d5286 in ~QListViewItem (this=0x84b6540) at widgets/qlistview.cpp:1020
No locals.
#2  0xb68313fd in ~KListViewItem (this=0x84b6540) at /home/ana/Debian/kdelibs/kdelibs-3.5.5a.dfsg.1/./kdeui/klistview.cpp:2206
No locals.
#3  0xb5422d4b in KMail::HeaderItem::~HeaderItem () from /usr/lib/libkmailprivate.so
No symbol table info available.
#4  0xb540c625 in KMHeaders::msgRemoved () from /usr/lib/libkmailprivate.so
No symbol table info available.
#5  0xb5506779 in KMHeaders::qt_invoke () from /usr/lib/libkmailprivate.so
No symbol table info available.
#6  0xb6fddd4f in QObject::activate_signal (this=0x83dd910, clist=0x8728960, o=0xbfd381b0) at kernel/qobject.cpp:2356
        object = (class QObject *) 0x849c3b8
        sol = (QSenderObjectList *) 0x849d010
        oldSender = (class QObject *) 0x0
        c = (QConnection *) 0x85fc688
#7  0xb531c120 in KMFolder::msgRemoved () from /usr/lib/libkmailprivate.so
No symbol table info available.
#8  0xb540174d in KMFolder::qt_emit () from /usr/lib/libkmailprivate.so
No symbol table info available.
#9  0xb6fddd23 in QObject::activate_signal (this=0x83e3ec8, clist=0x83dca30, o=0xbfd382a0) at kernel/qobject.cpp:2354
        object = (class QObject *) 0x83dd910
        sol = (QSenderObjectList *) 0x83de1f8
        oldSender = (class QObject *) 0x0
        c = (QConnection *) 0x83de0f8
#10 0xb531b230 in FolderStorage::msgRemoved () from /usr/lib/libkmailprivate.so
No symbol table info available.
#11 0xb547947b in FolderStorage::take () from /usr/lib/libkmailprivate.so
No symbol table info available.
#12 0xb55288cc in KMFolderMaildir::take () from /usr/lib/libkmailprivate.so
No symbol table info available.
#13 0xb52d348e in KMFolder::take () from /usr/lib/libkmailprivate.so
No symbol table info available.
#14 0xb5519e66 in KMFolderMaildir::addMsgInternal () from /usr/lib/libkmailprivate.so
No symbol table info available.
#15 0xb551a7a5 in KMFolderMaildir::addMsg () from /usr/lib/libkmailprivate.so
No symbol table info available.