From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 14 Dec 2016 17:57:55 GMT
Subject: Re: [PATCH] parse-options: print "fatal:" before usage_msg_opt()
Message-ID: <xmqqr35axujg.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20161214151009.4wdzjb44f6aki5ug@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Programs may use usage_msg_opt() to print a brief message
> followed by the program usage, and then exit. The message
> isn't prefixed at all, though, so it doesn't match our usual
> error output and is easy to overlook:
>
>     $ git clone 1 2 3
>     Too many arguments.
>
>     usage: git clone [<options>] [--] <repo> [<dir>]
>
>     -v, --verbose         be more verbose
>     -q, --quiet           be more quiet
>     --progress            force progress reporting
>     -n, --no-checkout     don't create a checkout
>     --bare                create a bare repository
>     [...and so on for another 31 lines...]
>
> It looks especially bad when the message starts with an
> option, like:
>
>     $ git replace -e
>     -e needs exactly one argument
>
>     usage: git replace [-f] <object> <replacement>
>        or: git replace [-f] --edit <object>
>     [...etc...]
>
> Let's put our usual "fatal:" prefix in front of it.

I briefly wondered if any caller uses this in a non-fatal situation,
but usage_with_options() always dies, so this looks like the right
thing to do.  Thanks.

>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
> Some of the message in git-clone could stand to be rewritten to match
> our usual style, too (no capitals, no trailing period), but that's
> obviously out of scope for this patch. I don't think this change makes
> them look any worse.
>
>  parse-options.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/parse-options.c b/parse-options.c
> index 312a85dbd..4fbe924a5 100644
> --- a/parse-options.c
> +++ b/parse-options.c
> @@ -661,7 +661,7 @@ void NORETURN usage_msg_opt(const char *msg,
>  		   const char * const *usagestr,
>  		   const struct option *options)
>  {
> -	fprintf(stderr, "%s\n\n", msg);
> +	fprintf(stderr, "fatal: %s\n\n", msg);
>  	usage_with_options(usagestr, options);
>  }