Re: [PATCH 07/10] submodule: migrate get_next_submodule to use repository structs

[Jonathan Tan <jonathantanmy@google.com>]

> We used to recurse into submodules, even if they were broken having
> only an objects directory. The child process executed in the submodule
> would fail though if the submodule was broken.
> 
> This patch tightens the check upfront, such that we do not need
> to spawn a child process to find out if the submodule is broken.

Thanks for the clear commit message. Also mention which tests currently
exercise this.

> +static struct repository *get_submodule_repo_for(struct repository *r,
> +						 const struct submodule *sub)
> +{
> +	struct repository *ret = xmalloc(sizeof(*ret));
> +
> +	if (repo_submodule_init(ret, r, sub)) {
> +		/*
> +		 * No entry in .gitmodules? Technically not a submodule,
> +		 * but historically we supported repositories that happen to be
> +		 * in-place where a gitlink is. Keep supporting them.
> +		 */
> +		struct strbuf gitdir = STRBUF_INIT;
> +		strbuf_repo_worktree_path(&gitdir, r, "%s/.git", sub->path);
> +		if (repo_init(ret, gitdir.buf, NULL)) {
> +			strbuf_release(&gitdir);

You should also free ret here.

> +			return NULL;
> +		}
> +		strbuf_release(&gitdir);
> +	}
> +
> +	return ret;
> +}

The above is the rest of get_submodule_repo_for(), so that we can see
that gitdir is indeed freed.

> -		if (!git_dir)
> -			git_dir = submodule_git_dir.buf;
> -		if (is_directory(git_dir)) {
> +		repo = get_submodule_repo_for(spf->r, submodule);
> +		if (repo) {
>  			child_process_init(cp);
> -			cp->dir = strbuf_detach(&submodule_path, NULL);
>  			prepare_submodule_repo_env(&cp->env_array);
> +			cp->dir = xstrdup(repo->worktree);

Move the cp->dir one line up for a cleaner diff.

[snip]

> +			repo_clear(repo);
> +			free(repo);
>  			ret = 1;
> +		} else {
> +			/*
> +			 * An empty directory is normal,
> +			 * the submodule is not initialized
> +			 */
> +			if (S_ISGITLINK(ce->ce_mode) &&
> +			    !is_empty_dir(ce->name))
> +				die(_("Could not access submodule '%s'"), ce->name);

Previously, a failed fetch would just set spf->result = 1 (in
fetch_finish()), allowing other fetches to still proceed. This sounds
like a better idea to me instead of die-ing outright. (Also remember to
print a warning message - since we no longer spawn a child process to
try a fetch that will fail, we need to print a message ourselves.)