1 files changed, 26 insertions, 1 deletions
diff --git a/src/multimedia/qgraphicsvideoitem_overlay.cpp b/src/multimedia/qgraphicsvideoitem_overlay.cpp
index b01a385987..1bcd329083 100644
--- a/src/multimedia/qgraphicsvideoitem_overlay.cpp
+++ b/src/multimedia/qgraphicsvideoitem_overlay.cpp
@@ -103,6 +103,7 @@ public:
     void clearService();
     void updateRects();
     void updateLastFrame();
+    void updateWindowId();
 
     void _q_present();
     void _q_updateNativeSize();
@@ -115,6 +116,30 @@ void QGraphicsVideoItemPrivate::_q_present()
 
 }
 
+void QGraphicsVideoItemPrivate::updateWindowId()
+{
+    const WId winId = videoWidget->winId();
+
+    // If the window ID is 0, it was not possible to promote the video widget from an alien widget
+    // to a native widget. As a last resort use the native ancestor instead.
+    if (winId == 0) {
+        // Do not use videoWidget->effectiveWinId(), it will assert inside qtwidget
+        // This stuff is broken in QPA.
+        QWidget *parent = videoWidget;
+        while (parent && !parent->winId()) {
+            parent = parent->parentWidget();
+        }
+
+        if (parent) {
+            windowControl->setWinId(parent->winId());
+            QPoint topLeft = videoWidget->mapTo(parent, QPoint(0, 0));
+            windowControl->setDisplayRect(QRect(topLeft, videoWidget->size()));
+        }
+    } else {
+        windowControl->setWinId(winId);
+    }
+}
+
 bool QGraphicsVideoItemPrivate::eventFilter(QObject *object, QEvent *event)
 {
     if (windowControl && object == videoWidget && QEvent::WinIdChange == event->type()) {
@@ -152,7 +177,7 @@ void QGraphicsVideoItemPrivate::setWidget(QWidget *widget)
     if (videoWidget != widget) {
         videoWidget = widget;
         if (widget) {
-            windowControl->setWinId(widget->winId());
+            updateWindowId();
             widget->installEventFilter(this);
         }
     }