Undo apply beam middle when also hooks and beams are initially selected

Follow-up of http://musescore.org/en/node/16047 :
1- Open BugBeam.mscz of comment #1 of http://musescore.org/en/node/16047
2- Drag select all the notes AND beams
3- Double click middle beam button in the palette
4- Undo -> crash

- Backtrace and log:
Debug: MuseScore::cmd
Debug: --undo index 0
Debug: Score(0x19630dd8)::addElement 0x196db3f8(Hook) parent 0x19b2ef90(Chord)
Debug: Score(0x19630dd8)::addElement 0x195b5ed8(Hook) parent 0x19cfc3c8(Chord)
Debug: Score(0x19630dd8)::addElement 0x19b2a760(Hook) parent 0x19b2bce8(Chord)
Debug: Score(0x19630dd8)::removeElement 0x196db3f8(Hook) parent 0x19b2ef90(Chord)
Debug: Score(0x19630dd8)::removeElement 0x195b5ed8(Hook) parent 0x19cfc3c8(Chord)

Program received signal SIGSEGV, Segmentation fault.
0x67878b4b in ZN14QWindowSurface8endPaintERK7QRegion () from C:\Git_packages\MuseScore\win32install\bin\QtGui4.dll
(gdb) bt
#0 0x67878b4b in ZN14QWindowSurface8endPaintERK7QRegion () from C:\Git_packages\MuseScore\win32install\bin\QtGui4.dll
#1 0x00405972 in Ms::StartDialog::qt_metacall(QMetaObject::Call, int, void**) () at C:\Git_packages\MuseScore\build.debug\mscore\moc_musescore.cxx:389
#2 0x005decfa in Ms::SaveState::undo (this=0x1a24b848) at C:\Git_packages\MuseScore\libmscore\undo.cpp:326
#3 0x005de681 in Ms::UndoCommand::undo (this=0x195b45b0) at C:\Git_packages\MuseScore\libmscore\undo.cpp:126
#4 0x005deaa4 in Ms::UndoStack::undo (this=0x19b18788) at C:\Git_packages\MuseScore\libmscore\undo.cpp:292
#5 0x004721c9 in Ms::MuseScore::undo (this=0x195ded38) at C:\Git_packages\MuseScore\mscore\musescore.cpp:2858
#6 0x00477b2a in Ms::MuseScore::cmd (this=0x195ded38, a=0x196942a8, cmd="undo") at C:\Git_packages\MuseScore\mscore\musescore.cpp:3982
#7 0x00476faf in Ms::MuseScore::cmd (this=0x195ded38, a=0x196942a8) at C:\Git_packages\MuseScore\mscore\musescore.cpp:3809
#8 0x00405e89 in Ms::MuseScore::qt_static_metacall (_o=0x195ded38, _c=QMetaObject::InvokeMetaMethod, _id=48, _a=0x28d3b8) at C:\Git_packages\MuseScore\build.debug\mscore\moc_musescore.cxx:582
#9 0x6e1c2fa5 in ZN11QMetaObject8activateEP7QObjectPKS_iPPv () from C:\Git_packages\MuseScore\win32install\bin\QtCore4.dll
#10 0x0028d3b8 in ?? ()

Windows 8, personal build of 0eae1ff3