AppKit's built in logic for customizing menu entries, such as adding
text input (emoji, dictation) entries to the Edit menu, happens via
[NSApplication _customizeMainMenu], which is triggered either from
[NSApplication finishedLaunching], or [NSApplication setMainMenu:],
but in the latter case, only if the menu is different.
In our case, we might be re-using the same menu as before, but the
menu now has additional sub menus such as an Edit menu. In that case
we still want AppKit to do its magic, so we need to reset the main
menu temporarily to nil so that AppKit sees the menu as a "new" menu.
Pick-to: 6.6 6.5 6.6.0
Fixes: QTBUG-116903
Change-Id: Ibd9da72fb81b7cd1d707bd350a62d0c93356dbd4
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
5994e94fd1