Member call on null pointer on destruction of QWebEnginePage

/Volumes/T3/Dev/qt/qt510_source/qtdeclarative/src/quick/items/qquickopenglshadereffectnode.cpp:369:58: runtime error: member call on null pointer of type 'QObject'
SUMMARY: AddressSanitizer: undefined-behavior /Volumes/T3/Dev/qt/qt510_source/qtdeclarative/src/quick/items/qquickopenglshadereffectnode.cpp:369:58 in
ASAN:DEADLYSIGNAL
=================================================================
==47701==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x00013b934ba8 bp 0x7fff563d9f10 sp 0x7fff563d9e20 T0)
==47701==The signal is caused by a READ memory access.
==47701==Hint: address points to the zero page.
[47702:775:1215/180415.686813:INFO:cpu_info.cc(50)] Available number of cores: 8
    #0 0x13b934ba7 in QQuickOpenGLShaderEffectMaterialCache::get(bool) qquickopenglshadereffectnode.cpp:369
    #1 0x13b935c84 in QQuickOpenGLShaderEffectMaterial::cleanupMaterialCache() qquickopenglshadereffectnode.cpp:462
    #2 0x13b58aacd in QQuickRenderControlPrivate::windowDestroyed() qquickrendercontrol.cpp:196
    #3 0x13b5896ab in QQuickRenderControl::~QQuickRenderControl() qquickrendercontrol.cpp:181
    #4 0x109a797e9 in QQuickWidgetRenderControl::~QQuickWidgetRenderControl() qquickwidget.cpp:79
    #5 0x109a38d5c in QQuickWidgetPrivate::~QQuickWidgetPrivate() qquickwidget.cpp:219
    #6 0x109a3a3a9 in QQuickWidgetPrivate::~QQuickWidgetPrivate() qquickwidget.cpp:209
    #7 0x148c01846 in QObject::~QObject() qscopedpointer.h:107
    #8 0x13d59974a in QWidget::~QWidget() qwidget.cpp:1735
    #9 0x10990bb7d in QtWebEngineCore::RenderWidgetHostViewQtDelegateWidget::~RenderWidgetHostViewQtDelegateWidget() render_widget_host_view_qt_delegate_widget.h:51
[47702:775:1215/180430.691969:INFO:child_thread_impl.cc(854)] ChildThreadImpl::EnsureConnected()
    #10 0x10c3fb45f in QtWebEngineCore::RenderWidgetHostViewQt::~RenderWidgetHostViewQt() memory:2537
    #11 0x10c3fbd19 in QtWebEngineCore::RenderWidgetHostViewQt::~RenderWidgetHostViewQt() render_widget_host_view_qt.cpp:364
    #12 0x10ea2c051 in content::RenderWidgetHostImpl::Destroy(bool) render_widget_host_impl.cc:1797
    #13 0x10ea2070c in content::RenderViewHostImpl::ShutdownAndDestroy() render_view_host_impl.cc:748
    #14 0x10e2e6ebf in content::FrameTree::ReleaseRenderViewHostRef(content::RenderViewHostImpl*) frame_tree.cc:371
    #15 0x10e37f2ff in content::RenderFrameHostImpl::~RenderFrameHostImpl() render_frame_host_impl.cc:605
    #16 0x10e381425 in content::RenderFrameHostImpl::~RenderFrameHostImpl() render_frame_host_impl.cc:546
    #17 0x10e40410b in content::RenderFrameHostManager::~RenderFrameHostManager() memory:2537
    #18 0x10e2ecde0 in content::FrameTreeNode::~FrameTreeNode() frame_tree_node.cc:191
    #19 0x10e2e2a01 in content::FrameTree::~FrameTree() frame_tree.cc:116
    #20 0x10ed331dc in content::WebContentsImpl::~WebContentsImpl() web_contents_impl.cc:653
    #21 0x10ed34b65 in content::WebContentsImpl::~WebContentsImpl() web_contents_impl.cc:546
    #22 0x10c4b843d in QtWebEngineCore::WebContentsAdapterPrivate::~WebContentsAdapterPrivate() memory:2537
    #23 0x10c4bc300 in QScopedPointer<QtWebEngineCore::WebContentsAdapterPrivate, QScopedPointerDeleter<QtWebEngineCore::WebContentsAdapterPrivate> >::~QScopedPointer() web_contents_adapter.cpp:365
    #24 0x10c4bc25a in QtWebEngineCore::WebContentsAdapter::~WebContentsAdapter() web_contents_adapter.cpp:407
    #25 0x1098a2811 in QSharedPointer<QtWebEngineCore::WebContentsAdapter>::deref(QtSharedPointer::ExternalRefCountData*) qsharedpointer_impl.h:157
    #26 0x10984f54a in QWebEnginePagePrivate::~QWebEnginePagePrivate() qwebenginepage.cpp:242
    #27 0x10984f889 in QWebEnginePagePrivate::~QWebEnginePagePrivate() qwebenginepage.cpp:239
    #28 0x10986501e in QWebEnginePage::~QWebEnginePage() qscopedpointer.h:107
    #29 0x1098653b9 in QWebEnginePage::~QWebEnginePage() qwebenginepage.cpp:814
    #30 0x148c0314b in QObjectPrivate::deleteChildren() qobject.cpp:1992
    #31 0x13d59928f in QWidget::~QWidget() qwidget.cpp:1711
    #32 0x1098d74a9 in QWebEngineView::~QWebEngineView() qwebengineview.cpp:148
    #33 0x148b2c60c in QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const qmetaobject.cpp:2305
    #34 0x109d22aed in QTest::TestMethods::invokeTestOnData(int) const qmetaobject.h:122
    #35 0x109d251a1 in QTest::TestMethods::invokeTest(int, char const*, QTest::WatchDog*) const qtestcase.cpp:1074
    #36 0x109d29f42 in QTest::TestMethods::invokeTests(QObject*) const qtestcase.cpp:1391
    #37 0x109d2d184 in QTest::qRun() qtestcase.cpp:1831
    #38 0x109d2c24f in QTest::qExec(QObject*, int, char**) qtestcase.cpp:1718
    #39 0x109828888 in main tst_qwebenginehistoryinterface.cpp:105
    #40 0x7fffcb6dc234 in start (libdyld.dylib:x86_64+0x5234)

==47701==Register values:
rax = 0x0000000000000000  rbx = 0x00007fff563d9e80  rcx = 0x0000000000000000  rdx = 0x0000000000000000
rdi = 0x9ddfea08eb382d69  rsi = 0x0000000000000000  rbp = 0x00007fff563d9f10  rsp = 0x00007fff563d9e20
 r8 = 0x000000000000003f   r9 = 0x0000000000000007  r10 = 0x00007fffcb80a966  r11 = 0x0000000000000206
r12 = 0x0000000000000000  r13 = 0x00007fff563d9e20  r14 = 0x000060d00004d000  r15 = 0x92f0c4d889f2fdb9
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV qquickopenglshadereffectnode.cpp:369 in QQuickOpenGLShaderEffectMaterialCache::get(bool)
==47701==ABORTING

class QQuickOpenGLShaderEffectMaterialCache : public QObject
{
    Q_OBJECT
public:
    static QQuickOpenGLShaderEffectMaterialCache *get(bool create = true) {
        QOpenGLContext *ctx = QOpenGLContext::currentContext();
        QQuickOpenGLShaderEffectMaterialCache *me = ctx->findChild<QQuickOpenGLShaderEffectMaterialCache *>(QStringLiteral("__qt_ShaderEffectCache"), Qt::FindDirectChildrenOnly);
        if (!me && create) {
            me = new QQuickOpenGLShaderEffectMaterialCache();
            me->setObjectName(QStringLiteral("__qt_ShaderEffectCache"));
            me->setParent(ctx);
        }
        return me;
    }
    QHash<QQuickOpenGLShaderEffectMaterialKey, QSGMaterialType *> cache;
};

diff --git a/src/quick/items/qquickopenglshadereffectnode.cpp b/src/quick/items/qquickopenglshadereffectnode.cpp
index 5dbfee73c..c23aa1954 100644
--- a/src/quick/items/qquickopenglshadereffectnode.cpp
+++ b/src/quick/items/qquickopenglshadereffectnode.cpp
@@ -366,7 +366,9 @@ class QQuickOpenGLShaderEffectMaterialCache : public QObject
 public:
     static QQuickOpenGLShaderEffectMaterialCache *get(bool create = true) {
         QOpenGLContext *ctx = QOpenGLContext::currentContext();
-        QQuickOpenGLShaderEffectMaterialCache *me = ctx->findChild<QQuickOpenGLShaderEffectMaterialCache *>(QStringLiteral("__qt_ShaderEffectCache"), Qt::FindDirectChildrenOnly);
+        QQuickOpenGLShaderEffectMaterialCache *me = 0;
+        if (ctx)
+            me = ctx->findChild<QQuickOpenGLShaderEffectMaterialCache *>(QStringLiteral("__qt_ShaderEffectCache"), Qt::FindDirectChildrenOnly);
         if (!me && create) {
             me = new QQuickOpenGLShaderEffectMaterialCache();
             me->setObjectName(QStringLiteral("__qt_ShaderEffectCache"));