Re: [PATCH 4/8] tag: Implicitly supply --list given another list-like option

[Jeff King <peff@peff.net>]

On Sat, Mar 18, 2017 at 10:32:52AM +0000, Ævar Arnfjörð Bjarmason wrote:

> With this change errors messages such as "--contains option is only
> allowed with -l" don't make sense anymore, since options like
> --contain turn on -l. Instead we error out when list-like options such
> as --contain are used in conjunction with conflicting options such as
> -d or -v.

Yeah, I think this is the right approach.

> This change does not consider "-n" a list-like option, even though
> that might be logical. Permitting it would allow:
> 
>     git tag -n 100
> 
> As a synonym for:
> 
>     git tag -n --list 100
> 
> Which, while not technically ambiguous as the option must already be
> provided as -n<num> rather than -n <num>, would be confusing.

I'm not sure the existing behavior isn't confusing anyway (most optional
arguments are). But I don't mind being conservative and leaving out "-n"
for now; we can always convert it later if somebody feels strongly about
it.

> diff --git a/builtin/tag.c b/builtin/tag.c
> index 0bba3fd070..3483636e59 100644
> --- a/builtin/tag.c
> +++ b/builtin/tag.c
> @@ -454,8 +454,12 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
>  	}
>  	create_tag_object = (opt.sign || annotate || msg.given || msgfile);
>  
> -	if (argc == 0 && !cmdmode && !create_tag_object)
> -		cmdmode = 'l';
> +	if (!cmdmode && !create_tag_object) {
> +		if (argc == 0)
> +			cmdmode = 'l';
> +		else if (filter.with_commit || filter.points_at.nr || filter.merge_commit)
> +			cmdmode = 'l';
> +	}

Makes sense.

> @@ -483,15 +487,16 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
>  		if (column_active(colopts))
>  			stop_column_filter();
>  		return ret;
> +	} else {
> +		if (filter.lines != -1)
> +			die(_("-n option is only allowed in list mode."));
> +		if (filter.with_commit)
> +			die(_("--contains option is only allowed in list mode."));
> +		if (filter.points_at.nr)
> +			die(_("--points-at option is only allowed in list mode."));
> +		if (filter.merge_commit)
> +			die(_("--merged and --no-merged options are only allowed in list mode."));
>  	}
> -	if (filter.lines != -1)
> -		die(_("-n option is only allowed with -l."));
> -	if (filter.with_commit)
> -		die(_("--contains option is only allowed with -l."));
> -	if (filter.points_at.nr)
> -		die(_("--points-at option is only allowed with -l."));
> -	if (filter.merge_commit)
> -		die(_("--merged and --no-merged option are only allowed with -l"));

I'm not sure why these go into the "else" clause here. The other side of
the conditional (i.e., when we are in list mode) always returns. I don't
_mind_ it, it's just surprising in this patch.

While we are re-wording the messages, we may want to drop the periods at
the end of the first three (or keep it on the fourth one, but I our
usual style is to omit it).

> --- a/t/t7004-tag.sh
> +++ b/t/t7004-tag.sh

The tests looked reasonable to me.

-Peff