Qt.labs.platform SystemTrayIcon (StatusNotifier) segfaults in QML Runtime if systray menu has a submenu

SystemTrayIcon {
   visible: true
   icon.source: "qrc:/icon.png"
   menu: Menu {
     MenuItem {
       text: qsTr("Nothing")
     }
     /* this submenu segfaults */
     Menu {}
   }
}

Thread 1 "minimal" received signal SIGSEGV, Segmentation fault.
0x00007ffff16d244a in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
(gdb) bt
#0 0x00007ffff16d244a in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#1 0x00007ffff16cd712 in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#2 0x00007ffff16ebe85 in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#3 0x00007ffff16ebe3e in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#4 0x00007ffff16ebf0c in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#5 0x00007ffff16ec0b1 in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#6 0x00007ffff16e59df in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#7 0x00007ffff16dd9e1 in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#8 0x00007ffff16de4f3 in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/platformthemes/libqgtk3.so
#9 0x00007ffff291263b in () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#10 0x00007ffff2917797 in () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#11 0x00007ffff2917f7e in () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#12 0x00007ffff291aae2 in () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#13 0x00007ffff7188d5a in QObject::event(QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#14 0x00007ffff7a68a66 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007ffff7a720f0 in QApplication::notify(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#16 0x00007ffff715c93a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007ffff715f5b8 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007ffff71b4f67 in () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007ffff5b4f17d in g_main_context_dispatch () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007ffff5b4f400 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007ffff5b4f4a3 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007ffff71b4565 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007ffff715b4db in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007ffff7163246 in QCoreApplication::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00005555555552c0 in main ()