From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 08 May 2020 16:38:17 GMT
Subject: Re: Re* [PATCH v4] submodule: port subcommand 'set-url' from shell to C
Message-ID: <xmqq4ksqz8jq.fsf@gitster.c.googlers.com>
In-Reply-To: <20200508161315.GA3504@flurp.local>

Eric Sunshine <sunshine@sunshineco.com> writes:

> From: Junio C Hamano <gitster@pobox.com>
> Subject: [PATCH] CodingGuidelines: do not ==/!= compare with 0 or '\0' or NULL
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
> ---
>  Documentation/CodingGuidelines | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> index 390ceece52..6dfc47ed7d 100644
> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -236,6 +236,18 @@ For C programs:
>          while( condition )
>  		func (bar+1);
>  
> + - Do not explicitly compare an integral value with constant 0 or '\0',
> +   or a pointer value with constant NULL.  For instance, to validate a
> +   counted array ptr that has cnt elements, write:

I think this should be

      counted array <ptr, cnt> is initialized but has no elements, write:

> +
> +	if (!ptr || cnt)
> +		BUG("empty array expected");
> +
> +   and not:
> +
> +	if (ptr == NULL || cnt != 0);
> +		BUG("empty array expected");
> +
>   - We avoid using braces unnecessarily.  I.e.
>  
>  	if (bla) {