# wrong check condition in patch-delta.c? 3 messages from 2006-06-20 to 2006-06-20. Participants: Nguyễn Thái Ngọc Duy, Marco Roeland, Nicolas Pitre. Thread: https://gitlist.dev/t/4581 ## Nguyễn Thái Ngọc Duy, 2006-06-20 06:32 Subject: wrong check condition in patch-delta.c? Message-ID: URL: https://gitlist.dev/e/fcaeb9bf0606192332j5b2ee4b9ycf2c63c7b1820204%40mail.gmail.com ``` Hi, 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? ``` ## Marco Roeland, 2006-06-20 07:21 Subject: Re: wrong check condition in patch-delta.c? Message-ID: <20060620072150.GB26656@fiberbit.xs4all.nl> URL: https://gitlist.dev/e/20060620072150.GB26656%40fiberbit.xs4all.nl In-Reply-To: ``` On Tuesday June 20th 2006 Nguy???n Thái Ng???c Duy wrote: > 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 ``` ## Nicolas Pitre, 2006-06-20 12:28 Subject: Re: wrong check condition in patch-delta.c? Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0606200827120.3377%40localhost.localdomain In-Reply-To: ``` On Tue, 20 Jun 2006, Nguyn Thái Ngc Duy wrote: > Hi, > 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? Yes, it absolutely is. Nicolas ```