Re: [PATCH 01/12] cache-tree: remove dependency on `the_repository`

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

Patrick Steinhardt <ps@pks.im> writes:

> The "cache-tree" subsystem still depends on `the_repository`. Adapt it
> to instead use repositories provided via the context, either as a new
> parameter or the one passed in via `struct index_state`.
>
> Besides getting rid of `the_repository`, this also removes the last
> dependency on registering submodule sources with the main object
> database. When reading gitmodules from a submodule's index we implicitly
> read that object via `the_repository`'s object database, which is of
> course wrong. This works though because we would then register the
> submodule's object database with the main object database, but a later
> patch is going to get rid of that mechanism.

As "the_repository, " is quite a long string, many lines bust our
usual ~70 column limit, but other than that the changes look quite
straight-forward.

We probably should make the cache_tree_fully_valid() into file scope
static.  Your new cache_tree_fully_valid() that takes the repository
and a cache_tree, which will be file-scope static, will gain a new
thin wrapper around it, i.e.,

    int has_valid_cache_tree(struct index_state *istate)
    {
	return cache_tree_fully_valid(istate->repo, istate->cache_tree);
    }

Migrate the callers outside cache_tree.c file to use it; outside the
implementation, nobody has any business talking about a subdirectory
of any cache-tree, or any cache-tree outside the context of the istate
it belongs to.

Other than that, looking good.