--- qtdeclarative/src/quick/items/qquickevents.cpp	Mon Nov 19 13:39:18 2018
+++ qtdeclarative/src/quick/items/qquickevents.cpp	Sun Jan 06 12:03:15 2019
@@ -1610,8 +1610,8 @@
 
 Qt::TouchPointStates QQuickPointerTouchEvent::touchPointStates() const
 {
-    return m_event
-        ? static_cast<QTouchEvent*>(m_event)->touchPointStates()
+    return m_event && dynamic_cast<QTouchEvent *>(m_event)
+        ? dynamic_cast<QTouchEvent*>(m_event)->touchPointStates()
         : Qt::TouchPointStates();
 }
 
--- qtdeclarative/src/quick/items/qquickevents_p_p.h	Mon Nov 19 13:39:18 2018
+++ qtdeclarative/src/quick/items/qquickevents_p_p.h	Sun Jan 06 12:05:08 2019
@@ -491,8 +491,8 @@
     bool isDoubleClickEvent() const override;
     bool isUpdateEvent() const override;
     bool isReleaseEvent() const override;
-    QQuickPointerMouseEvent *asPointerMouseEvent() override { return this; }
-    const QQuickPointerMouseEvent *asPointerMouseEvent() const override { return this; }
+    QQuickPointerMouseEvent *asPointerMouseEvent() override { return m_event && dynamic_cast<QMouseEvent *>(m_event)? this : nullptr; }
+    const QQuickPointerMouseEvent *asPointerMouseEvent() const override { return m_event && dynamic_cast<QMouseEvent *>(m_event)? this : nullptr; }
 
     QMouseEvent *asMouseEvent(const QPointF& localPos) const;
 
@@ -513,8 +513,8 @@
     bool isPressEvent() const override;
     bool isUpdateEvent() const override;
     bool isReleaseEvent() const override;
-    QQuickPointerTouchEvent *asPointerTouchEvent() override { return this; }
-    const QQuickPointerTouchEvent *asPointerTouchEvent() const override { return this; }
+    QQuickPointerTouchEvent *asPointerTouchEvent() override { return m_event && dynamic_cast<QTouchEvent *>(m_event)? this : nullptr; }
+    const QQuickPointerTouchEvent *asPointerTouchEvent() const override { return m_event && dynamic_cast<QTouchEvent *>(m_event)? this : nullptr; }
     int pointCount() const override { return m_pointCount; }
     QQuickEventPoint *point(int i) const override;
     QQuickEventPoint *pointById(int pointId) const override;
--- qtdeclarative/src/quick/items/qquickwindow.cpp	Mon Nov 19 13:39:18 2018
+++ qtdeclarative/src/quick/items/qquickwindow.cpp	Wed Jan 16 17:01:03 2019
@@ -2488,6 +2488,7 @@
     int pointCount = event->pointCount();
     for (int i = 0; i < pointCount; ++i) {
         QQuickEventPoint *point = event->point(i);
+        if (!point) continue;
         deliverToPassiveGrabbers(point->passiveGrabbers(), event);
     }
 
@@ -2499,6 +2500,7 @@
         QVector<QQuickItem *> targetItems;
         for (int i = 0; i < pointCount; ++i) {
             QQuickEventPoint *point = event->point(i);
+            if (!point) continue;
             if (point->state() == QQuickEventPoint::Pressed)
                 continue; // presses were delivered earlier; not the responsibility of deliverUpdatedTouchPoints
             QVector<QQuickItem *> targetItemsForPoint = pointerTargets(contentItem, point, false, false);
@@ -2526,8 +2528,9 @@
     int pointCount = event->pointCount();
     QVector<QQuickItem *> targetItems;
     bool isTouchEvent = (event->asPointerTouchEvent() != nullptr);
+    QQuickEventPoint *pt = nullptr;
     if (isTouchEvent && event->isPressEvent() && isDeliveringTouchAsMouse() &&
-            pointerEventInstance(touchMouseDevice)->pointById(touchMouseId)->grabberPointerHandler()) {
+            (pt = pointerEventInstance(touchMouseDevice)->pointById(touchMouseId)) && pt->grabberPointerHandler()) {
         // When a second point is pressed, if the first point's existing
         // grabber was a pointer handler while a filtering parent is filtering
         // the same first point _as mouse_: we're starting over with delivery,
@@ -2563,7 +2566,7 @@
         if (!handlersOnly && sendFilteredPointerEvent(event, item)) {
             if (event->isAccepted()) {
                 for (int i = 0; i < event->pointCount(); ++i)
-                    event->point(i)->setAccepted();
+                    if (auto p = event->point(i)) p->setAccepted();
                 return true;
             }
             skipDelivery.append(item);
@@ -2611,11 +2614,13 @@
     auto event = pointerEvent->asPointerMouseEvent();
     if (event && item->acceptedMouseButtons() & event->button()) {
             auto point = event->point(0);
+            if (!point) return;
             // The only reason to already have a mouse grabber here is
             // synthetic events - flickable sends one when setPressDelay is used.
             auto oldMouseGrabber = q->mouseGrabberItem();
             QPointF localPos = item->mapFromScene(point->scenePosition());
             QMouseEvent *me = event->asMouseEvent(localPos);
+            if (!me) return;
             me->accept();
             QCoreApplication::sendEvent(item, me);
             if (me->isAccepted()) {