Re: [PATCH 2/2] submodule: port init from shell to C

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

Stefan Beller <sbeller@google.com> writes:

> By having the `init` functionality in C, we can reference it easier
> from other parts in the code.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  builtin/submodule--helper.c | 107 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            |  39 +---------------
>  submodule.c                 |  21 +++++++++
>  submodule.h                 |   1 +
>  4 files changed, 130 insertions(+), 38 deletions(-)
>
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index d1e9118..30e623a 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -214,6 +214,112 @@ static int resolve_relative_url_test(int argc, const char **argv, const char *pr
>  	return 0;
>  }
>  
> +static void init_submodule(const char *path, const char *prefix, int quiet)
> +{
> +	const struct submodule *sub;
> +	struct strbuf sb = STRBUF_INIT;
> +	char *url = NULL;
> +	const char *upd = NULL;
> +	char *cwd = xgetcwd();
> +	const char *displaypath = relative_path(cwd, prefix, &sb);
> +
> +	/* Only loads from .gitmodules, no overlay with .git/config */
> +	gitmodules_config();

This feeds submodule_config() function with the contents of
".gitmodules".

> +	sub = submodule_from_path(null_sha1, path);
> +
> +	/*
> +	 * Copy url setting when it is not set yet.
> +	 * To look up the url in .git/config, we must not fall back to
> +	 * .gitmodules, so look it up directly.
> +	 */
> +	strbuf_reset(&sb);
> +	strbuf_addf(&sb, "submodule.%s.url", sub->name);
> +	if (git_config_get_string(sb.buf, &url)) {
> +		url = xstrdup(sub->url);
> +		if (!url)
> +			die(_("No url found for submodule path '%s' in .gitmodules"),
> +				displaypath);

I am assuming that this corresponds to these lines in the original
scripted version:

		url=$(git config -f .gitmodules submodule."$name".url)
		test -z "$url" &&
		die "$(eval_gettext "No url found for submodule path...

but what makes git_config_get_string() to read from ".gitmodules"
file?  Doesn't it read from $GIT_DIR/config & ~/.gitconfig instead?

> +		/* Possibly a url relative to parent */
> +		if (starts_with_dot_dot_slash(url) ||
> +		    starts_with_dot_slash(url)) {
> +			char *remoteurl;
> +			char *remote = get_default_remote();
> +			struct strbuf remotesb = STRBUF_INIT;
> +			strbuf_addf(&remotesb, "remote.%s.url", remote);
> +			free(remote);
> +
> +			if (git_config_get_string(remotesb.buf, &remoteurl))
> +				/*
> +				 * The repository is its own
> +				 * authoritative upstream
> +				 */
> +				remoteurl = xgetcwd();
> +			url = relative_url(remoteurl, url, NULL);
> +			strbuf_release(&remotesb);
> +			free(remoteurl);

Does the code inside this block correspond to this single line in
the original?

	url=$(git submodule--helper resolve-relative-url "$url") || exit

It seems to be doing quite a different thing, though.

> +		}
> +
> +		if (git_config_set(sb.buf, url))
> +			die(_("Failed to register url for submodule path '%s'"),
> +			    displaypath);
> +		if (!quiet)
> +			printf(_("Submodule '%s' (%s) registered for path '%s'\n"),
> +				sub->name, url, displaypath);
> +	}
> +
> +	/* Copy "update" setting when it is not set yet */
> +	strbuf_reset(&sb);
> +	strbuf_addf(&sb, "submodule.%s.update", sub->name);
> +	if (git_config_get_string_const(sb.buf, &upd) &&



This part of the code is supposed to read from in-tree ".gitmodules"
and copy to $GIT_DIR/config (i.e. git_config_set() below), but
again, I am not sure what makes this read from ".gitmodules".

Puzzled.

> +	    sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
> +		if (sub->update_strategy.type == SM_UPDATE_COMMAND) {
> +			fprintf(stderr, _("warning: command update mode suggested for submodule '%s'\n"),
> +				sub->name);
> +			upd = "none";
> +		} else
> +			upd = submodule_strategy_to_string(&sub->update_strategy);
> +
> +		if (git_config_set(sb.buf, upd))
> +			die(_("Failed to register update mode for submodule path '%s'"), displaypath);
> +	}
> +	strbuf_release(&sb);
> +	free(cwd);
> +	free(url);
> +}