apply() reports two different things through one bool: an input that changed
a value, and a field it had to fill in because the config carried none. The
update-settings gate reads that bool as "the caller asked for a change", so
any config still missing a default answered a request that asks for nothing
with a refusal.
Readers already hand out normalized configs — readConfig applies an empty
input for exactly this reason — which is why the gate got away with it. But a
handler that refuses a request must not depend on where its caller obtained
the config, and it must not start reading "this profile predates a field" as
"the caller asked for a change" the day someone adds one with a default.
WouldChange now runs the filling-in as a pass of its own and discards its
verdict, so the pass that answers the caller measures only what the input
did.
riccardom
e998887977