Use of listId.currentIndex in delegate results in segfault

color: ListView.isCurrentItem ? "green" : "blue"

color: index == menuView.currentIndex ? "green" : "blue"

Program received signal SIGSEGV, Segmentation fault.
malloc_consolidate (av=<value optimised out>) at malloc.c:5138
5138    malloc.c: No such file or directory.
        in malloc.c
(gdb) bt
#0  malloc_consolidate (av=<value optimised out>) at malloc.c:5138
#1  0xb5738afd in _int_malloc (av=<value optimised out>, bytes=<value optimised out>) at malloc.c:4372
#2  0xb573ba6c in _int_realloc (av=<value optimised out>, oldp=0x820c108, oldsize=264, nb=520) at malloc.c:5273
#3  0xb573bf9d in *__GI___libc_realloc (oldmem=0x820c110, bytes=514) at malloc.c:3821
#4  0xb5ae206a in qRealloc (ptr=0x820c110, size=514) at global/qmalloc.cpp:65
#5  0xb5b3d227 in QString::realloc (this=0xbfffe8b8, alloc=248) at tools/qstring.cpp:1345
#6  0xb5b3d887 in QString::append (this=0xbfffe8b8, str=...) at tools/qstring.cpp:1562
#7  0xb5b44a75 in QString::vsprintf (this=0xbfffe918, cformat=0xb5ca05d8 "ASSERT failure in %s: \"%s\", file %s, line %d", ap=0xbfffe980 "c\001") at tools/qstring.cpp:5441
#8  0xb5adddf6 in qt_message (msgType=QtFatalMsg, msg=0xb5ca05d8 "ASSERT failure in %s: \"%s\", file %s, line %d", ap=0xbfffe974 "\005\063\071\267\227\062\071\267\304\062\071\267c\001")
    at global/qglobal.cpp:2245
#9  0xb5ade227 in qFatal (msg=0xb5ca05d8 "ASSERT failure in %s: \"%s\", file %s, line %d") at global/qglobal.cpp:2432
#10 0xb5add86a in qt_assert_x (where=0xb7393305 "QVector<T>::operator[]", what=0xb7393297 "index out of range", file=0xb73932c4 "../../../qtbase/include/QtCore/../../src/corelib/tools/qvector.h", line=355)
    at global/qglobal.cpp:1960
#11 0xb72a62c9 in QVector<QDeclarativeChangeSet::Insert>::operator[](int) const () from /home/user/depot/qt/qt5/qtbase/lib/libQtDeclarative.so.5
#12 0xb72a503d in QSGItemViewPrivate::applyModelChanges (this=0x811b078) at items/qsgitemview.cpp:1486
#13 0xb72a48a2 in QSGItemViewPrivate::layout (this=0x811b078) at items/qsgitemview.cpp:1387
#14 0xb72a313e in QSGItemView::updatePolish (this=0x815a328) at items/qsgitemview.cpp:1074
#15 0xb71e54b1 in QSGCanvasPrivate::polishItems (this=0x80dc4b0) at items/qsgcanvas.cpp:370
#16 0xb71ed532 in QSGCanvasRenderLoop::polishItems (this=0x8119248) at items/qsgcanvas_p.h:204
#17 0xb71edd2c in QSGCanvasPlainRenderLoop::paint (this=0x8119240) at items/qsgcanvas.cpp:97
#18 0xb71ee019 in QSGCanvasPlainRenderLoop::event (this=0x8119240, e=0x8208690) at items/qsgcanvas.cpp:147
#19 0xb764fdda in QApplicationPrivate::notify_helper (this=0x809ed78, receiver=0x8119240, e=0x8208690) at kernel/qapplication.cpp:4243
#20 0xb764d727 in QApplication::notify (this=0xbffff36c, receiver=0x8119240, e=0x8208690) at kernel/qapplication.cpp:3638
#21 0xb5c13c58 in QCoreApplication::notifyInternal (this=0xbffff36c, receiver=0x8119240, event=0x8208690) at kernel/qcoreapplication.cpp:826
#22 0xb7ea0219 in QCoreApplication::sendEvent (receiver=0x8119240, event=0x8208690) at ../../../qtbase/include/QtCore/../../src/corelib/kernel/qcoreapplication.h:207
#23 0xb5c14d5a in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x809e5a8) at kernel/qcoreapplication.cpp:1468
#24 0xb5c14829 in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1338
#25 0xb5f03cf6 in QCoreApplication::sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:212
#26 0xb5c4eaba in postEventSourceDispatch (s=0x80aa110) at kernel/qeventdispatcher_glib.cpp:279
#27 0xb55ee5e5 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#28 0xb55f22d8 in ?? () from /lib/libglib-2.0.so.0
#29 0xb55f24b8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#30 0xb5c4fb32 in QEventDispatcherGlib::processEvents (this=0x80a3058, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#31 0xb5c10e0f in QEventLoop::processEvents (this=0xbffff2bc, flags=...) at kernel/qeventloop.cpp:149
#32 0xb5c11075 in QEventLoop::exec (this=0xbffff2bc, flags=...) at kernel/qeventloop.cpp:225
#33 0xb5c142c9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1093
#34 0xb5f118db in QGuiApplication::exec () at kernel/qguiapplication.cpp:451
#35 0xb764d3de in QApplication::exec () at kernel/qapplication.cpp:3517
#36 0x0804daf9 in main (argc=2, argv=0xbffff564) at main.cpp:517