High DPI painting errors for widgets in scroll area if QT_SCALE_FACTOR is a point number > 1

If a QT_SCALE_FACTOR point number is used (e.g. 1.25 or 1.5 - typical values on today's monitors with Windows 10), painting errors occur, if widgets are placed inside of a scroll area and the scrollbars are used to scroll the scroll area content.

The attached application shows this issue. Start the application with the included StartHighDpiFixed_125.bat. Then scroll around and move the mouse over the widgets in the scroll area to see the painting issues.