Subject: Re: [PATCH] completion: add and use the __git_get_config_subsection helper function

From: Junio C Hamano <[email-masked]>
Date: Tue, 14 Nov 2023 10:08:46 +0900

SZEDER Gábor <[email-masked]> writes:

> +# Lists all subsections in the given section which contain the given
> +# config variable, with the section and variable names removed.
> +__git_get_config_subsections ()
> +{
> +	local section="$1" var="$2" i IFS=$'\n'
> +	for i in $(__git config --name-only --get-regexp "^$section\..*\.$var$"); do
> +		i=${i#$section.}
> +		i=${i%.$var}

As this script is allowed bash-isms, I wondered if we can use
a single pattern substitution instead of two remove pre/suffix
pattern substitution, but I guess it would not work, and the above
is perfectly readable.

> +		echo "$i"

As the subsection is designed to contain unbounded set of end-user
controlled names, we probably should do

		printf "%s\n" "$i"

instead to protect us from interesting names (e.g. ones that begin
with a dash).

> +	done
> +}

Interesting to see that we do not need to bother deduplicating the
output from here.

> diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
> index a7c3b4eb63..11ed83d0ed 100755
> --- a/t/t9902-completion.sh
> +++ b/t/t9902-completion.sh
> @@ -2130,6 +2130,19 @@ test_expect_success '__git_get_config_variables' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success '__git_get_config_subsections' '
> +	cat >expect <<-\EOF &&
> +	subsection-1
> +	SubSection-2
> +	sub.section.3
> +	EOF
> +	test_config interesting.subsection-1.name good &&
> +	test_config Interesting.SubSection-2.Name good &&
> +	test_config interesting.sub.section.3.name good &&
> +	__git_get_config_subsections interesting name >actual &&
> +	test_cmp expect actual
> +'

Good to see an uppercase character is used here ;-).

Thanks.