> +/*
> + * Initialize 'out' based on the provided submodule path.
> + *
> + * Unlike repo_submodule_init, this tolerates submodules not present
> + * in .gitmodules. This function exists only to preserve historical behavior,
> + *
> + * Returns 0 on success, -1 when the submodule is not present.
> */
> -static void show_submodule_header(struct diff_options *o, const char *path,
> +static struct repository *open_submodule(const char *path)
The function documentation needs to be reworded - there's no "out", and
the return value is now a possibly NULL pointer to struct repository.
> +{
> + struct strbuf sb = STRBUF_INIT;
> + struct repository *out = xmalloc(sizeof(*out));
> +
> + if (submodule_to_gitdir(&sb, path) || repo_init(out, sb.buf, NULL)) {
> + strbuf_release(&sb);
> + free(out);
> + return NULL;
> + }
> +
> + out->submodule_prefix = xstrdup(path);
I've discussed this submodule_prefix line before [1] - do we really need
this? Tests pass even if I remove this line.
Other than that, this patch looks good.
[1] https://public-inbox.org/git/20181019203750.110741-1-jonathantanmy@xxxxxxxxxx/
