Re: [PATCH 1/4] Improve message-id generation flow control for format-patch

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

Daniel Barkalow <barkalow@iabervon.org> writes:

> Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
> ---
>  builtin-log.c |   29 ++++++++++++++---------------
>  1 files changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/builtin-log.c b/builtin-log.c
> index dcc9f81..1f74d66 100644
> --- a/builtin-log.c
> +++ b/builtin-log.c
> @@ -576,16 +576,19 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const cha
>  	o2->flags = flags2;
>  }
>  
> -static void gen_message_id(char *dest, unsigned int length, char *base)
> +static void gen_message_id(struct rev_info *info, char *base)
>  {
>  	const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
>  	const char *email_start = strrchr(committer, '<');
>  	const char *email_end = strrchr(committer, '>');
> -	if(!email_start || !email_end || email_start > email_end - 1)
> +	struct strbuf buf;
> +	if (!email_start || !email_end || email_start > email_end - 1)
>  		die("Could not extract email from committer identity.");
> -	snprintf(dest, length, "%s.%lu.git.%.*s", base,
> -		 (unsigned long) time(NULL),
> -		 (int)(email_end - email_start - 1), email_start + 1);
> +	strbuf_init(&buf, 0);
> +	strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
> +		    (unsigned long) time(NULL),
> +		    (int)(email_end - email_start - 1), email_start + 1);
> +	info->message_id = buf.buf;

I wonder how the rule established by b315c5c (strbuf change: be
sure ->buf is never ever NULL) and at the beginning of strbuf.h
applies here.  I think the current implementation of strbuf
happens to allow this, and it is very handy.  Perhaps the rule
stated there should be loosened and allow copying the buf away
when you know you have stuff in there (i.e. ->buf != slopbuf).
Pierre, what do you think?

What the patch does itself is much nicer than the original.