From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 12 Sep 2012 18:37:31 GMT
Subject: Re: [PATCH 2/3] sha1: clean pointer arithmetic
Message-ID: <7vd31rcck4.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20dce012a57900b61e51c0e0d8dfb5573693010e.1347442430.git.ydroneaud@opteya.com>

Yann Droneaud <ydroneaud@opteya.com> writes:

> One memcpy() argument is computed from a pointer added to an integer:
> eg. int + pointer. It's unusal.
> Let's write it in the correct order: pointer + offset.

Meh.

Both are correct.  Aren't ctx->w[lenW] and lenW[ctx-w] both correct,
even?


>
> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
> ---
>  block-sha1/sha1.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block-sha1/sha1.c b/block-sha1/sha1.c
> index c1af112..a7c4470 100644
> --- a/block-sha1/sha1.c
> +++ b/block-sha1/sha1.c
> @@ -246,7 +246,7 @@ void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
>  		unsigned int left = 64 - lenW;
>  		if (len < left)
>  			left = len;
> -		memcpy(lenW + (char *)ctx->W, data, left);
> +		memcpy((char *)ctx->W + lenW, data, left);
>  		lenW = (lenW + left) & 63;
>  		if (lenW)
>  			return;