Re: wrong check condition in patch-delta.c?

From: Marco Roeland <marco.roeland@xs4all.nl>
Date: Jun 20, 2006, 07:21 UTC
Message-ID: <20060620072150.GB26656@fiberbit.xs4all.nl>
In-Reply-To: <fcaeb9bf0606192332j5b2ee4b9ycf2c63c7b1820204@mail.gmail.com>

On Tuesday June 20th 2006 Nguy???n Thái Ng???c Duy wrote:

Show 6 quoted lines

> While inspecting patch-delta.c, I encounter this:
>                       if (cp_off + cp_size < cp_size ||
>                           cp_off + cp_size > src_size ||
>                           cp_size > size)
>                               goto bad;
> "cp_off + cp_size < cp_size" doesn't make sense to me. Is it on purpose?

It protects against possible overflow. Adding fixed length integers is "wraparound" after all and discards the "carry" bit.

-- 
Marco Roeland