GNU bug report logs - #33128
cmp -l misses differences

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Hans-Joachim Baader <Hans-Joachim.Baader <at> cjt.de>
To: "bug-diffutils <at> gnu.org" <bug-diffutils <at> gnu.org>
Subject: cmp -l misses differences
Date: Tue, 23 Oct 2018 12:44:34 +0000

[Message part 1 (text/plain, inline)]

Hi,

it seems that "cmp -l" doesn't list all differences. The attached blobs differ
among others at positions 0x437 (1079), 0x4b7 (1207) and 0x5b7 (1463).
One file contains 0x80 at these positions, the other 0. cmp shows neither of
these. I tested with 3.5 and Git Head.

It would be interesting to compare with other implementations, but I don't
have one available.

Regards,
Hans-Joachim Baader

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Message #10 received at 33128-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Hans-Joachim Baader <Hans-Joachim.Baader <at> cjt.de>,
 33128-done <at> debbugs.gnu.org
Subject: Re: [bug-diffutils] bug#33128: cmp -l misses differences
Date: Tue, 23 Oct 2018 17:07:47 -0700

On 10/23/18 5:44 AM, Hans-Joachim Baader wrote:
> it seems that "cmp -l" doesn't list all differences. The attached blobs differ
> among others at positions 0x437 (1079), 0x4b7 (1207) and 0x5b7 (1463).

cmp uses origin 1, not origin 0, and it reports all the positions you 
mentioned; it just adds 1 to them.

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