ModelParticle crashes occasionally on taking the first model item

[Thread debugging using libthread_db enabled]
Qml debugging is enabled. Only use this in a safe environment!
Qt: gdb: -nograb added to command-line options.
         Use the -dograb option to enforce grabbing.
[New Thread 0xb121fb70 (LWP 15691)]
[New Thread 0xb040eb70 (LWP 15692)]
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Program received signal SIGSEGV, Segmentation fault.
0xb6ef230b in QSGModelParticle::processPending (this=0x81fb428) at particles/qsgmodelparticle.cpp:184
184                 datum->delegate = m_model->item(m_available.first());
(gdb) bt
#0  0xb6ef230b in QSGModelParticle::processPending (this=0x81fb428) at particles/qsgmodelparticle.cpp:184
#1  0xb6f42e88 in QSGModelParticle::qt_static_metacall (_o=0x81fb428, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfffe9d8)
    at .moc/debug-shared/moc_qsgmodelparticle_p.cpp:89
#2  0xb55ec3b0 in QMetaObject::activate (sender=0x81f0450, m=0xb577048c, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3342
#3  0xb5650501 in QTimer::timeout (this=0x81f0450) at .moc/debug-shared/moc_qtimer.cpp:142
#4  0xb55f50f2 in QTimer::timerEvent (this=0x81f0450, e=0xbfffefc8) at kernel/qtimer.cpp:250
#5  0xb55e7b30 in QObject::event (this=0x81f0450, e=0xbfffefc8) at kernel/qobject.cpp:1067
#6  0xb5d04eaa in QApplicationPrivate::notify_helper (this=0x80a0778, receiver=0x81f0450, e=0xbfffefc8) at kernel/qapplication.cpp:4497
#7  0xb5d02769 in QApplication::notify (this=0xbffff364, receiver=0x81f0450, e=0xbfffefc8) at kernel/qapplication.cpp:3879
#8  0xb55cee73 in QCoreApplication::notifyInternal (this=0xbffff364, receiver=0x81f0450, event=0xbfffefc8) at kernel/qcoreapplication.cpp:831
#9  0xb7ea0f5b in QCoreApplication::sendEvent (receiver=0x81f0450, event=0xbfffefc8) at ../../../qtbase/include/QtCore/../../src/corelib/kernel/qcoreapplication.h:212
#10 0xb560d92c in QTimerInfoList::activateTimers (this=0x80a7234) at kernel/qeventdispatcher_unix.cpp:611
#11 0xb56094d7 in timerSourceDispatch (source=0x80a7200) at kernel/qeventdispatcher_glib.cpp:186
#12 0xb560958f in idleTimerSourceDispatch (source=0x80a6da0) at kernel/qeventdispatcher_glib.cpp:233
#13 0xb4d2d5e5 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#14 0xb4d312d8 in ?? () from /lib/libglib-2.0.so.0
#15 0xb4d314b8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#16 0xb560a6ee in QEventDispatcherGlib::processEvents (this=0x80a4178, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#17 0xb5ddc3ce in QGuiEventDispatcherGlib::processEvents (this=0x80a4178, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#18 0xb55cbdd3 in QEventLoop::processEvents (this=0xbffff2bc, flags=...) at kernel/qeventloop.cpp:149
#19 0xb55cbf46 in QEventLoop::exec (this=0xbffff2bc, flags=...) at kernel/qeventloop.cpp:204
#20 0xb55cf4fb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1103
#21 0xb5d02422 in QApplication::exec () at kernel/qapplication.cpp:3758
#22 0x08050338 in main (argc=2, argv=0xbffff544) at main.cpp:568