Re: [PATCH v2 18/24] gpg-interface: improve interface for parsing tags

> We have a function which parses a buffer with a signature at the end,
> parse_signature, and this function is used for signed tags.  However,
> the transition plan has SHA-256 tags using a header, which is a
> materially different syntax.  The current interface is not suitable for
> parsing such tags.
>
> Adjust the parse_signature interface to store the parsed data in two
> strbufs and turn the existing function into parse_signed_buffer.  The
> latter is still used in places where we want to strip off the signature
> in a SHA-1 tag or in places where we know we always have a signed
> buffer, such as push certs.
>
> Adjust all the callers to deal with this new interface.
>
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
>  builtin/fmt-merge-msg.c | 26 ++++++++++++++++++--------
>  builtin/receive-pack.c  |  4 ++--
>  builtin/tag.c           | 16 ++++++++++++----
>  commit.c                |  9 ++++++---
>  gpg-interface.c         | 13 ++++++++++++-
>  gpg-interface.h         |  9 ++++++++-
>  log-tree.c              | 14 ++++++++------
>  ref-filter.c            | 18 ++++++++++++++----
>  tag.c                   | 15 ++++++++-------
>  9 files changed, 88 insertions(+), 36 deletions(-)
>
> diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
> index 05a92c59d8..29f647e2d9 100644
> --- a/builtin/fmt-merge-msg.c
> +++ b/builtin/fmt-merge-msg.c
> @@ -472,6 +472,7 @@ static void fmt_tag_signature(struct strbuf *tagbuf,
>  			      const char *buf,
>  			      unsigned long len)
>  {
> +
>  	const char *tag_body = strstr(buf, "\n\n");
>  	if (tag_body) {
>  		tag_body += 2;

> diff --git a/gpg-interface.c b/gpg-interface.c
> index 2d538bcd6e..b25f5c21d8 100644
> --- a/gpg-interface.c
> +++ b/gpg-interface.c
> @@ -345,7 +345,7 @@ void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
>  		fputs(output, stderr);
>  }
>  
> -size_t parse_signature(const char *buf, size_t size)
> +size_t parse_signed_buffer(const char *buf, size_t size)
>  {
>  	size_t len = 0;
>  	size_t match = size;
> @@ -361,6 +361,17 @@ size_t parse_signature(const char *buf, size_t size)
>  	return match;
>  }
>  
> +int parse_signature(const char *buf, size_t size, struct strbuf *payload, struct strbuf *signature)
> +{
> +	size_t match = parse_signed_buffer(buf, size);
> +	if (match != size) {
> +		strbuf_add(payload, buf, match);
> +		strbuf_add(signature, buf + match, size - match);
> +		return 1;
> +	}
> +	return 0;
> +}
> +