Subject: Re: [PATCH v2 18/34] sequencer (rebase -i): refactor setting the reflog message

From: Junio C Hamano <[email-masked]>
Date: Fri, 16 Dec 2016 11:28:51 -0800

Johannes Schindelin <[email-masked]> writes:

> This makes the code DRYer, with the obvious benefit that we can enhance
> the code further in a single place.
>
> We can also reuse the functionality elsewhere by calling this new
> function.
>
> Signed-off-by: Johannes Schindelin <[email-masked]>
> ---
>  sequencer.c | 33 ++++++++++++++++++++++++++-------
>  1 file changed, 26 insertions(+), 7 deletions(-)
>
> diff --git a/sequencer.c b/sequencer.c
> index 33fb36dcbe..d20efad562 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -1750,6 +1750,26 @@ static int is_final_fixup(struct todo_list *todo_list)
>  	return 1;
>  }
>  
> +static const char *reflog_message(struct replay_opts *opts,
> +	const char *sub_action, const char *fmt, ...)
> +{
> +	va_list ap;
> +	static struct strbuf buf = STRBUF_INIT;
> +
> +	va_start(ap, fmt);
> +	strbuf_reset(&buf);
> +	strbuf_addstr(&buf, action_name(opts));
> +	if (sub_action)
> +		strbuf_addf(&buf, " (%s)", sub_action);
> +	if (fmt) {
> +		strbuf_addstr(&buf, ": ");
> +		strbuf_vaddf(&buf, fmt, ap);
> +	}
> +	va_end(ap);
> +
> +	return buf.buf;
> +}

It is unlikely for a single caller to want to format another reflog
entry after formating one but before consuming it [*1*], so this
"call this, and you can use the return value until you call it the
next time without worrying about leakage" is quite a reasonable
pattern to employ.

[Footnote]

*1* And it is unlikely that this will run in a multi-threaded
    environment, either ;-)