Re: [RFC PATCH 2/4] tag: add --hash=sha256 to sign a tree-sha256 header

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

Scott Chacon <scott@gitbutler.net> writes:

> @@ -316,11 +318,19 @@ static void create_tag(const struct object_id *object, const char *object_ref,
>  		    "object %s\n"
>  		    "type %s\n"
>  		    "tag %s\n"
> -		    "tagger %s\n\n",
> +		    "tagger %s\n",
>  		    oid_to_hex(object),
>  		    type_name(type),
>  		    tag,
>  		    git_committer_info(IDENT_STRICT));
> +	if (opt->sign && opt->tree_hash) {
> +		strbuf_addstr(&header, TREE_SHA256_HEADER " ");
> +		if (tree_sha256_hex(the_repository, object, &header))
> +			die(_("unable to compute %s for %s"),
> +			    TREE_SHA256_HEADER, object_ref);
> +		strbuf_addch(&header, '\n');
> +	}
> +	strbuf_addch(&header, '\n');

This is a very nice reorganization.  The hardcoded double LF at the
end was a declaration that we wanted to make it hard to add new
fields, but it becomes a hindrance when we want to add an optional
field.