Segfault when adding a linked tab staff to a populated score

GIT commit: efb6d19

If I add a linked staff to the current pitch staff, then change the type of the new staff to tab, it segfaults. I provide a file where it is reproducible. I'm using Ubuntu 12.04. Here follows a stack trace:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000674417 in QBasicAtomicInt::ref (this=0x7620746501000118) at /usr/include/qt4/QtCore/qatomic_x86_64.h:121
121 : "memory");
(gdb) bt
#0 0x0000000000674417 in QBasicAtomicInt::ref (this=0x7620746501000118) at /usr/include/qt4/QtCore/qatomic_x86_64.h:121
#1 0x000000000067447c in QString::QString (this=0x7fffffffa530, other=...) at /usr/include/qt4/QtCore/qstring.h:726
#2 0x0000000000afa263 in StaffTypeTablature::fretString (this=0x6f3a590, fret=-1, ghost=false) at /home/johan/Projects/MuseScore/libmscore/stafftype.cpp:687
#3 0x0000000000ab0588 in Note::layout (this=0x70dd8a0) at /home/johan/Projects/MuseScore/libmscore/note.cpp:1280
#4 0x0000000000a23901 in Chord::layout (this=0x70dd460) at /home/johan/Projects/MuseScore/libmscore/chord.cpp:1338
#5 0x0000000000a88346 in Score::computeMinWidth (this=0x6fca4a0, fs=0x7015530) at /home/johan/Projects/MuseScore/libmscore/layout.cpp:2658
#6 0x0000000000aa3343 in Measure::minWidth1 (this=0x7014580) at /home/johan/Projects/MuseScore/libmscore/measure.cpp:2803
#7 0x0000000000a80b22 in Score::layoutSystem (this=0x6fca4a0, minWidth=@0x7fffffffb100: 221.65430182813728, w=718.10946666666678, isFirstSystem=true, longName=true)
at /home/johan/Projects/MuseScore/libmscore/layout.cpp:1011
#8 0x0000000000a8352c in Score::layoutSystemRow (this=0x6fca4a0, rowWidth=718.10946666666678, isFirstSystem=true, useLongName=true) at /home/johan/Projects/MuseScore/libmscore/layout.cpp:1699
#9 0x0000000000a8569f in Score::layoutSystems (this=0x6fca4a0) at /home/johan/Projects/MuseScore/libmscore/layout.cpp:2065
#10 0x0000000000a7ee5f in Score::doLayout (this=0x6fca4a0) at /home/johan/Projects/MuseScore/libmscore/layout.cpp:642
#11 0x0000000000b4e3c6 in Score::end2 (this=0x6fca4a0) at /home/johan/Projects/MuseScore/libmscore/cmd.cpp:166
#12 0x0000000000b4dff7 in Score::endCmd (this=0x6fca4a0) at /home/johan/Projects/MuseScore/libmscore/cmd.cpp:116
#13 0x0000000000692bcf in ScoreView::measurePopup (this=0x6fcf260, gpos=..., obj=0x701c8a0) at /home/johan/Projects/MuseScore/mscore/scoreview.cpp:1117
#14 0x000000000069cd9c in ScoreView::contextPopup (this=0x6fcf260, ev=0x70ffac0) at /home/johan/Projects/MuseScore/mscore/scoreview.cpp:2920
#15 0x00000000006aa989 in ContextTransition::onTransition (this=0x6ff0ba0, e=0x6f78470) at /home/johan/Projects/MuseScore/mscore/scoreview.cpp:181
#16 0x00007ffff396e4a9 in QStateMachinePrivate::executeTransitionContent(QEvent*, QList const&) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#17 0x00007ffff3977e0b in QStateMachinePrivate::microstep(QEvent*, QList const&) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#18 0x00007ffff3975632 in QStateMachinePrivate::_q_process() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#19 0x00007ffff397818b in QStateMachinePrivate::handleFilteredEvent(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#20 0x00007ffff397826d in QStateMachine::eventFilter(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#21 0x00007ffff3933028 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#22 0x00007ffff43e485f in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#23 0x00007ffff43e9bcd in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#24 0x00007ffff3932e9c in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#25 0x00007ffff4464c58 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#26 0x00007ffff4463bae in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#27 0x00007ffff448d0d2 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#28 0x00007fffefaa0d53 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffefaa10a0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fffefaa1164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007ffff39623bf in QEventDispatcherGlib::processEvents(QFlags) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#32 0x00007ffff448cd5e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#33 0x00007ffff3931c82 in QEventLoop::processEvents(QFlags) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#34 0x00007ffff3931ed7 in QEventLoop::exec(QFlags) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#35 0x00007ffff3936f67 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#36 0x00000000007a24d0 in main (argc=1, av=0x7fffffffe238) at /home/johan/Projects/MuseScore/mscore/musescore.cpp:2475
(gdb)