after some “investigations”, i do believe it is some sort of a bug…
the documented KIO API has support for the old and the new path, but IMHO in the wrong order (as new actions are not added, if one of the same name already exists in. see: QWidget Class | Qt Widgets 5.15.15):
personaly i can’t handle this #if KIOWIDGETS_BUILD_DEPRECATED_SINCE(5, 85) line, that implies the included code will not be translated since framework version 85, but i’m running 110 and the old path based .desktop actions are not(!) ignored.
the latest(?) code has no support for the old path at all:
can someone shed some light into my likely wrong understanding?
or: how can i see, what actual code my current build 110 is made from?