crash in tasks applet

[Bart Cerneels]

Hi all,

I've been getting consistent crashes for the past week. Still
happends with revision 877334. So I hope this helps you to fix it.

Tips to reproduce:
* enable only show minimized windows.
* unminimized a window by clicking on it in the task panel.
I'm also using a vertically oriented panel, which might be a case not
tested by the people working on the tasks applet.

Here is the backtrace:

plasma(17074) TaskManager::GroupManager::remove: remove:  "Gmail -
Inbox - bart.cerneels at gmail.com - Mozilla Firefox"

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb53336c0 (LWP 17074)]
0xb665f7a3 in QMetaObject::invokeMethod (obj=0x83fd238,
   member=0xb7f24094 "toolTipAboutToShow", type=Qt::AutoConnection, ret=
       {<QGenericArgument> = {_data = 0x0, _name = 0x0}, <No data
fields>}, val0=
     {_data = 0x0, _name = 0x0}, val1={_data = 0x0, _name = 0x0},
val2=
     {_data = 0x0, _name = 0x0}, val3={_data = 0x0, _name = 0x0},
val4=
     {_data = 0x0, _name = 0x0}, val5={_data = 0x0, _name = 0x0},
val6=
     {_data = 0x0, _name = 0x0}, val7={_data = 0x0, _name = 0x0},
val8=
     {_data = 0x0, _name = 0x0}, val9={_data = 0x0, _name = 0x0})
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qmetaobject.cpp:951
951         int idx =
obj->metaObject()->indexOfMethod(sig.constData());
(gdb) bt
#0  0xb665f7a3 in QMetaObject::invokeMethod (obj=0x83fd238,
   member=0xb7f24094 "toolTipAboutToShow", type=Qt::AutoConnection,
ret=
       {<QGenericArgument> = {_data = 0x0, _name = 0x0}, <No data
fields>}, val0=
     {_data = 0x0, _name = 0x0}, val1={_data = 0x0, _name = 0x0}, val2=
     {_data = 0x0, _name = 0x0}, val3={_data = 0x0, _name = 0x0}, val4=
     {_data = 0x0, _name = 0x0}, val5={_data = 0x0, _name = 0x0}, val6=
     {_data = 0x0, _name = 0x0}, val7={_data = 0x0, _name = 0x0}, val8=
     {_data = 0x0, _name = 0x0}, val9={_data = 0x0, _name = 0x0})
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qmetaobject.cpp:951
#1  0xb7e8b1ac in Plasma::ToolTipManagerPrivate::showToolTip (this=0x817dd00)
   at /opt/qt-copy/include/QtCore/qobjectdefs.h:388
#2  0xb7e8b444 in Plasma::ToolTipManager::qt_metacall (this=0x81e9a18,
   _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfe55f98)
   at /home/bart/Code/KDE/trunk/build/KDE/kdebase/workspace/libs/plasma/tooltipmanager.moc:70
#3  0xb666c0a9 in QMetaObject::activate (sender=0x817dd40, from_signal_index=4,
   to_signal_index=4, argv=0x0)
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qobject.cpp:3007
#4  0xb666c772 in QMetaObject::activate (sender=0x817dd40, m=0xb674cc44,
   local_signal_index=0, argv=0x0)
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qobject.cpp:3077
#5  0xb66a9997 in QTimer::timeout (this=0x817dd40)
   at .moc/release-shared/moc_qtimer.cpp:126
#6  0xb667322e in QTimer::timerEvent (this=0x817dd40, e=0xbfe56468)
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qtimer.cpp:263
#7  0xb6666baa in QObject::event (this=0x817dd40, e=0xbfe56468)
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/corelib/kernel/qobject.cpp:1096
#8  0xb6af286c in QApplicationPrivate::notify_helper (this=0x80804f8,
   receiver=0x817dd40, e=0xbfe56468)
   at /home/bart/Code/KDE/trunk/KDE/qt-copy/src/gui/kernel/qapplication.cpp:3800
#9  0xb6af4909 in QApplication::notify (this=0x8062dd0, receiver=0x817dd40,
   e=0xbfe56468)