Re: Silly 'git am' UI issue

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

Linus Torvalds <torvalds@linux-foundation.org> writes:

> On Thu, Mar 3, 2022 at 1:58 PM Junio C Hamano <gitster@pobox.com> wrote:
>>
>> I wonder if something like this would have helped.
>
> That would certainly have helped, yes.
>
> But I think we can do better.
>
> How about just parsing the "--whitespace" option in 'git am' before
> passing it through?
>
> Something like the attached patch seems to work for me.
>
> With this one, I simply get
>
>     $ git am --whitespace 0001-Dummy.patch
>     error: unrecognized whitespace option '0001-Dummy.patch'
>
> when I make the mistake of not giving that whitespace argument.
>
> I'm not claiming this is extensively tested, but I did *some* testing
> on it, and it's not a complicated patch.
>
>              Linus

Yup, reusing what apply.c already uses gives reviewers a solid
assurance.  It already is named appropriately for a global
namespace, so the patch text, as far as I can see, looks good
enough.

> +static int parse_opt_whitespace(const struct option *opt, const char *arg, int unset)
> +{
> +	struct apply_state dummy = { };

It is rare to see a completely empty initializer in this codebase, I
think.

> +	if (parse_whitespace_option(&dummy, arg))
> +		return -1;
> +
> +	return parse_opt_passthru_argv(opt, arg, unset);
> +}

Looks good.

>  static int git_am_config(const char *k, const char *v, void *cb)
>  {
>  	int status;
> @@ -2355,9 +2365,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
>  		OPT_CALLBACK_F(0, "quoted-cr", &state.quoted_cr, N_("action"),
>  			       N_("pass it through git-mailinfo"),
>  			       PARSE_OPT_NONEG, am_option_parse_quoted_cr),
> -		OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
> +		OPT_CALLBACK(0, "whitespace", &state.git_apply_opts, N_("action"),
>  			N_("pass it through git-apply"),
> -			0),
> +			parse_opt_whitespace),
>  		OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
>  			N_("pass it through git-apply"),
>  			PARSE_OPT_NOARG),