Amends 402efef57bb6a04ad778d3139100becc2cba31eb. The original patch has a problem, namely that it directly calls QPlatformWindow::requestUpdate() instead of going through QWindow::requestUpdate(). As there is a chance that an update gets scheduled between the creation of the QPlatformWindow and this extra, optional invocation of requestUpdate() at the end of QWindow::create(), this becomes quite unsafe because QPlatformWindow, unlike QWindow, is not graceful: it will just assert if there is a pending update still. Solve the whole thing by storing the updateRequestPending flag of QWindowPrivate, then resetting it, and then going through the safe, public QWindow::requestUpdate() when our copy of the flag says so. Task-number: QTBUG-81400 Task-number: QTBUG-70957 Pick-to: 5.15 Change-Id: I99aedfae3928b75301b46a4666c169e657ff8079 Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>