Re: [PATCH 1/4] refs: add referent parameter to refs_resolve_ref_unsafe

[Junio C Hamano <gitster@pobox.com>]

Patrick Steinhardt <ps@pks.im> writes:

> I wonder whether we can future-proof the code a bit more by introducing
> a struct that contains everything we want to pass to the callback
> function.

That would hopefully make a change with a large blast a one-time
event.  But at the same time, it may end up making it too opaque and
hard to verify if all the API functions are using/updating/verifying
all the members of the struct as they should.  Compared to that,
unused parameters are easier to verify mechanically by compilers.

> This would also allow us to get rid of this awful `peel_iterated_oid()`
> function that relies on global state in many places, as we can put the
> peeled OID into that structure, as well.

Yes, such a benefit may justify a one-time "affect many callers"
event.  Or the underlying for_each_*() friend of functions can be
updated to use a single struct and then the current "only selected
parameters that are used ar passed" API can be made into a set of
thin wrappers around it, and then callers can be converted one step
at a time, in a multi-step series, perhaps.