Don't use WWrapPointer if has monitor aboutToBeInvalidated

Author: wineee

src/server/qtquick/private/wsurfaceitem_p.h

@@ -64,7 +64,7 @@ class Q_DECL_HIDDEN WSurfaceItemPrivate : public QQuickItemPrivate
     }
 
     Q_DECLARE_PUBLIC(WSurfaceItem)
-    WWrapPointer<WSurface> surface;
+    WSurface *surface = nullptr;
     WWrapPointer<WToplevelSurface> shellSurface;
     std::unique_ptr<SurfaceState> surfaceState;
     QQuickItem *contentContainer = nullptr;

src/server/qtquick/wsurfaceitem.cpp

@@ -271,7 +271,7 @@ class Q_DECL_HIDDEN WSurfaceItemContentPrivate: public QQuickItemPrivate
     }
 
     W_DECLARE_PUBLIC(WSurfaceItemContent)
-    WWrapPointer<WSurface> surface;
+    WSurface *surface = nullptr;
     QRectF bufferSourceBox;
     QPoint bufferOffset;
     qreal devicePixelRatio = 1.0;
@@ -900,6 +900,7 @@ void WSurfaceItem::releaseResources()
 
     if (d->surface) {
         d->surface->safeDisconnect(this);
+        d->surface = nullptr;
     }
 
     if (!d->surfaceFlags.testFlag(DontCacheLastBuffer)) {