Re: [PATCH 04/12] setup: start tracking ref storage format when

> In order to discern which ref storage format a repository is supposed to
> use we need to start setting up and/or discovering the format. This
> needs to happen in two separate code paths.
>
>   - The first path is when we create a repository via `init_db()`. When
>     we are re-initializing a preexisting repository we need to retain
>     the previously used ref storage format -- if the user asked for a
>     different format then this indicates an erorr and we error out.

> diff --git a/refs.c b/refs.c
> index e87c85897d..d289a5e175 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -2045,12 +2045,12 @@ static struct ref_store *ref_store_init(struct repository *repo,
>  					const char *gitdir,
>  					unsigned int flags)
>  {
> -	int format = REF_STORAGE_FORMAT_FILES;
> -	const struct ref_storage_be *be = find_ref_storage_backend(format);
> +	const struct ref_storage_be *be;
>  	struct ref_store *refs;
>
> +	be = find_ref_storage_backend(repo->ref_storage_format);
>  	if (!be)
> -		BUG("reference backend %s is unknown", ref_storage_format_to_name(format));
> +		BUG("reference backend is unknown");
>
>  	refs = be->init(repo, gitdir, flags);
>  	return refs;
> diff --git a/refs.h b/refs.h
> index c6571bcf6c..944a67ac1b 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -11,6 +11,7 @@ struct string_list;
>  struct string_list_item;
>  struct worktree;
>
> +int default_ref_storage_format(void);
>