Re: [PATCH] builtin: pass repository to sub commands

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

Patrick Steinhardt <ps@pks.im> writes:

> So if the code were refactored to instead accept an arbitrary `void *`
> pointer, callers could provide a custom structure and pass that along to
> its subcommands. In many cases we may end up just passing the repo
> directly, but I'm sure there are others where this direction would buy
> us additional flexibility and allow us to get rid of even more global
> state.

I am of two minds.  Certainly for OPT_SUBCOMMAND macro to be able to
work with arbitrary types that are specific to each git subcommand,
we'd need "void *" plus casting on the receiving end.  But it loses
type safety.

I personally think (but not so strongly) that we should add a repo
to parse_opt_subcommand_fn(), if this exercise is about giving
consistent access to the repository object universally across
subsubcommands.

If we want flexibility on top, we can either add another "void *"
for it after we are done with adding the repository, or we may even
be able to make the parse_opt_subcommand_fn() a varargs.