crash in wayland client due to null QWaylandShm

$ qml main.qml -platform wayland

1  QtWayland::wl_shm::object                             qwayland-wayland.h          168 
2  QtWaylandClient::QWaylandShmBuffer::QWaylandShmBuffer qwaylandshmbackingstore.cpp 113 
3  QtWaylandClient::QWaylandShmBackingStore::getBuffer   qwaylandshmbackingstore.cpp 264 
4  QtWaylandClient::QWaylandShmBackingStore::resize      qwaylandshmbackingstore.cpp 285 
5  QtWaylandClient::QWaylandShmBackingStore::ensureSize  qwaylandshmbackingstore.cpp 206 
6  QtWaylandClient::QWaylandShmBackingStore::beginPaint  qwaylandshmbackingstore.cpp 181 
7  QBackingStore::beginPaint                             qbackingstore.cpp           138 
8  QSGSoftwareRenderer::render                           qsgsoftwarerenderer.cpp     107 
9  QSGRenderer::renderScene                              qsgrenderer.cpp             264 
10 QSGSoftwareRenderer::renderScene                      qsgsoftwarerenderer.cpp     95  
11 QSGSoftwareRenderContext::renderNextFrame             qsgsoftwarecontext.cpp      161 
12 QQuickWindowPrivate::renderSceneGraph                 qquickwindow.cpp            609 
13 QSGSoftwareRenderLoop::renderWindow                   qsgsoftwarerenderloop.cpp   175 
14 QSGSoftwareRenderLoop::exposureChanged                qsgsoftwarerenderloop.cpp   227 
15 QQuickWindow::exposeEvent                             qquickwindow.cpp            237 
16 QWindow::event                                        qwindow.cpp                 2435
17 QQuickWindow::event                                   qquickwindow.cpp            1905
18 QCoreApplicationPrivate::notify_helper                qcoreapplication.cpp        1225
19 doNotify                                              qcoreapplication.cpp        1154
20 QCoreApplication::notify                              qcoreapplication.cpp        1140
21 QGuiApplication::notify                               qguiapplication.cpp         1938
22 QCoreApplication::notifyInternal2                     qcoreapplication.cpp        1064
23 QCoreApplication::sendSpontaneousEvent                qcoreapplication.cpp        1474
24 QGuiApplicationPrivate::processExposeEvent            qguiapplication.cpp         3261
25 QGuiApplicationPrivate::processWindowSystemEvent      qguiapplication.cpp         2073
26 QWindowSystemInterface::sendWindowSystemEvents        qwindowsysteminterface.cpp  1169
27 userEventSourceDispatch                               qeventdispatcher_glib.cpp   74  
28 ??                                                                                    
29 ??                                                                                    
30 g_main_context_iteration                                                              
31 QEventDispatcherGlib::processEvents                   qeventdispatcher_glib.cpp   423 
32 QPAEventDispatcherGlib::processEvents                 qeventdispatcher_glib.cpp   120 
33 QEventLoop::processEvents                             qeventloop.cpp              142 
34 QEventLoop::exec                                      qeventloop.cpp              235 
35 QCoreApplication::exec                                qcoreapplication.cpp        1375
36 main                                                  main.cpp                    651 

QWaylandShmBuffer::QWaylandShmBuffer(QWaylandDisplay *display,
                     const QSize &size, QImage::Format format, int scale)
{
...
    QWaylandShm* shm = display->shm();
    wl_shm_format wl_format = shm->formatFrom(format); 
    mImage = QImage(data, size.width(), size.height(), stride, format);
    mImage.setDevicePixelRatio(qreal(scale));

    mShmPool = wl_shm_create_pool(shm->object(), fd, alloc); // <---
    init(wl_shm_pool_create_buffer(mShmPool,0, size.width(), size.height(),
                                       stride, wl_format));
}