Destructing the QWindowsScreenManager might result in a
WM_DISPLAYCHANGE, at which point our QWindowsContext instance
is likely gone. We need to guard against that.
Fixes: QTBUG-117473
Pick-to: 6.5
Change-Id: If32941c5c11231f7c27e9dde54f4315f18da1100
Reviewed-by: Wladimir Leuschner <wladimir.leuschner@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Timothée Keller <timothee.keller@qt.io>
(cherry picked from commit 7d663d2e08fb71801f0f1f084a124e706722bf0f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
d599451e24