Re: [PATCH] parse-options: disallow negating OPTION_SET_INT 0

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

René Scharfe <l.s.r@web.de> writes:

> An option of type OPTION_SET_INT can be defined to set its variable to
> zero.  It's negated variant will do the same, though, which is
> confusing.  Several such options were fixed by disabling negation,
> changing the value to set or using a different option type:
>
> 991c552916 (ls-tree: fix --no-full-name, 2023-07-18)
> e12cb98e1e (branch: reject "--no-all" and "--no-remotes" early, 2023-07-18)
> 68cbb20e73 (show-branch: reject --[no-](topo|date)-order, 2023-07-19)
> 3821eb6c3d (reset: reject --no-(mixed|soft|hard|merge|keep) option, 2023-07-19)
> 36f76d2a25 (pack-objects: fix --no-quiet, 2023-07-21)
> 3a5f308741 (pack-objects: fix --no-keep-true-parents, 2023-07-21)
> c95ae3ff9c (describe: fix --no-exact-match, 2023-07-21)
> d089a06421 (bundle: use OPT_PASSTHRU_ARGV, 2023-07-29)
>
> Check for such options that allow negation in parse_options_check() and
> report them to find future cases quicker.

That does make quite a lot of sense, and parse_options_check() is
the perfect place to do so.

Thanks.

> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
>  parse-options.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/parse-options.c b/parse-options.c
> index 87c9fae634..60224cf8d0 100644
> --- a/parse-options.c
> +++ b/parse-options.c
> @@ -480,6 +480,9 @@ static void parse_options_check(const struct option *opts)
>  		     opts->long_name))
>  			optbug(opts, "uses feature "
>  			       "not supported for dashless options");
> +		if (opts->type == OPTION_SET_INT && !opts->defval &&
> +		    opts->long_name && !(opts->flags & PARSE_OPT_NONEG))
> +			optbug(opts, "OPTION_SET_INT 0 should not be negatable");
>  		switch (opts->type) {
>  		case OPTION_COUNTUP:
>  		case OPTION_BIT:
> --
> 2.41.0