FileDropSetSettings committed the mode first, through a Set that persists it
and fires the handler binding the receiver, and only then validated the
destination. A destination the caller may not use returned an error the UI
read as "nothing changed", while the profile had already moved to
auto-accept with the receiver listening, so the next offer from any peer was
taken without a prompt and delivered to the old directory.
Both halves are now settled before either is applied, and applied in the one
Set that already carries them: it validates the mode before touching
anything, so a refusal on either half leaves the policy alone.
Zoltán Papp
ab47d2a4bf