Version:           unspecified (using KDE 4.6.3) 
OS:                Linux

Attempt to double click on shaded windows group couse kwin crush.

Reproducible: Always

Steps to Reproduce:
1) system settings -> window begavior -> titlebar actions -> titlebar wheel event: "shade/unshade"
2) group some windows e.g. konsole and dolphin into one window
3) shade into small strip
4) doubleclick on titlebar
5) kwin crushed

Actual Results:  
Kwin crush

Expected Results:  
Same as single/not grouped shaded windows

Application: KWin (kwin), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fa4102d5780 (LWP 19791))]

Thread 2 (Thread 0x7fa3f6894700 (LWP 19797)):
#0  0x00007fa40bb8aa34 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fa40e995192 in ?? () from /usr/lib/libQtScript.so.4
#2  0x00007fa40e9951c9 in ?? () from /usr/lib/libQtScript.so.4
#3  0x00007fa40bb86d40 in start_thread () from /lib/libpthread.so.0
#4  0x00007fa40fb4aaed in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fa4102d5780 (LWP 19791)):
[KCrash Handler]
#6  0xffffffd8ffffffd8 in ?? ()
#7  0x00007fa40fe251ea in ?? () from /usr/lib/libkdeinit4_kwin.so
#8  0x00007fa40fe25626 in ?? () from /usr/lib/libkdeinit4_kwin.so
#9  0x00007fa40fe7be09 in ?? () from /usr/lib/libkdeinit4_kwin.so
#10 0x00007fa40fe7ce16 in ?? () from /usr/lib/libkdeinit4_kwin.so
#11 0x00007fa40fe7d1ba in ?? () from /usr/lib/libkdeinit4_kwin.so
#12 0x00007fa40fe7dae5 in ?? () from /usr/lib/libkdeinit4_kwin.so
#13 0x00007fa40fe76fb8 in ?? () from /usr/lib/libkdeinit4_kwin.so
#14 0x00007fa40e1bf04f in KCommonDecoration::eventFilter(QObject*, QEvent*) () from /usr/lib/libkdecorations.so.4
#15 0x00007fa3f6c2b290 in ?? () from /usr/lib/kde4/kwin3_oxygen.so
#16 0x00007fa40bef67b8 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#17 0x00007fa40b0b713f in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#18 0x00007fa40b0bc8fb in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#19 0x00007fa40f6569c6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#20 0x00007fa40bef662c in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#21 0x00007fa40b0b8142 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/libQtGui.so.4
#22 0x00007fa40b134528 in ?? () from /usr/lib/libQtGui.so.4
#23 0x00007fa40b13332a in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#24 0x00007fa40b15af3a in ?? () from /usr/lib/libQtGui.so.4
#25 0x00007fa40bef5832 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#26 0x00007fa40bef5a2f in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#27 0x00007fa40bef9c07 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#28 0x00007fa40fe30abd in kdemain () from /usr/lib/libkdeinit4_kwin.so
#29 0x00007fa40fa99f6d in __libc_start_main () from /lib/libc.so.6
#30 0x00000000004005f1 in _start ()