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

> diff --git a/builtin-log.c b/builtin-log.c
> index 99d69f0..867cc13 100644
> --- a/builtin-log.c
> +++ b/builtin-log.c
> @@ -575,16 +575,19 @@ 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 = strbuf_detach(&buf, NULL);

> @@ -809,15 +810,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
>  		rev.nr = total - nr + (start_number - 1);
>  		/* Make the second and subsequent mails replies to the first */
>  		if (thread) {
> -			if (nr == (total - 2)) {
> -				strncpy(ref_message_id, message_id,
> -					sizeof(ref_message_id));
> -				ref_message_id[sizeof(ref_message_id)-1]='\0';
> -				rev.ref_message_id = ref_message_id;
> +			if (rev.message_id) {
> +				if (rev.ref_message_id)
> +					free((char *) rev.message_id);