Re: [PATCH] repack: fix geometric repacking with gitalternates

> > Perhaps this method could include a step to create a new, "local"
> > geometry containing only the packs within the local object dir. We can
> > then skip the --preferred-pack option and bitmap if this is different
> > than the original geometry (perhaps with a warning message to help
> > users who did this accidentally).
> 
> It would be nice to not have to juggle multiple pack geometry structs,
> since the logic of what gets repacked, what gets thrown away, and what
> gets kept is already fairly complicated (at least to me) and pretty
> fragile.
> 
> I think if I were sketching this out, I'd start out by doing something
> like:
> 
> --- 8< ---
> diff --git a/builtin/repack.c b/builtin/repack.c
> index df4d8e0f0b..eab5f58444 100644
> --- a/builtin/repack.c
> +++ b/builtin/repack.c
> @@ -558,6 +558,10 @@ static void midx_included_packs(struct string_list *include,
>  		for (i = geometry->split; i < geometry->pack_nr; i++) {
>  			struct packed_git *p = geometry->pack[i];
> 
> +			/* MIDXs cannot refer to non-local packs */
> +			if (!p->pack_local)
> +				continue;
> +
>  			strbuf_addstr(&buf, pack_basename(p));
>  			strbuf_strip_suffix(&buf, ".pack");
>  			strbuf_addstr(&buf, ".idx");
> --- >8 ---
> 
> ...and I actually think that might do it, since:
> 
> 	- existing_nonkept_packs is populated by calling readdir() on the local
> 		repository's $GIT_DIR/objects/pack directory, so it will never contain
> 		any non-local packs.
> 
> 	- existing_kept_packs is also OK for the same reason
> 
> 	- names (which tracks the packs that we just wrote) will never contain a
> 		non-local pack, since we never write packs outside of our local pack
> 		directory
> 
> So that would cause you to write a MIDX containing only local packs (as
> desired) regardless of whether or not the caller passed --[no]-local or
> not.