Amends da754d5b65
We should avoid registering an observer multiple times for the same
NSMenu object, because it results in multiple consecutive
emitActivated() calls.
So,
- bail out early if menu is the same, i.e. we have nothing to do
- unregister an observer we added previously for the old menu
Fixes: QTBUG-119053
Pick-to: 6.6 6.5
Change-Id: I14fce693dba351b1d12f2140fa8e672227cc7a9e
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
5b451efe81