Re: [PATCH 2/6] CodingGuidelines: quote assigned value in 'local var=$val'

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Apr 6, 2024, 05:16 UTC
Message-ID: <CAPig+cR8HxO5ZeZrJQ4PtpgsqM__cvieZ6g37F1m_=ng6xvSPA@mail.gmail.com>
In-Reply-To: <20240406000902.3082301-3-gitster@pobox.com>

On Fri, Apr 5, 2024 at 8:09 PM Junio C Hamano <gitster@pobox.com> wrote:

Show 26 quoted lines

> Dash bug https://bugs.launchpad.net/ubuntu/+source/dash/+bug/139097
> lets the shell erroneously perform field splitting on the expansion
> of a command substitution during declaration of a local or an extern
> variable.
>
> The explanation was stolen from ebee5580 (parallel-checkout: avoid
> dash local bug in tests, 2021-06-06).
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> @@ -194,6 +194,20 @@ For shell scripts specifically (not exhaustive):
> + - Some versions of dash have broken variable assignment when prefixed
> +   with "local", "export", and "readonly", in that the value to be
> +   assigned goes through field splitting at $IFS unless quoted.
> +
> +   DO NOT write:
> +
> +     local variable=$value           ;# wrong
> +     local variable=$(command args)  ;# wrong
> +
> +   and instead write:
> +
> +     local variable="$value"
> +     local variable="$(command args)"
> +

Every other example in the shell-script section of this document is written like this:

    (incorrect)
    local variable=$value
    local variable=$(command args)

    (correct)
    local variable="$value"
    local variable="$(command args)"

Should this patch follow suit for consistency?