From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: [REVISED PATCH 2/6] Introduce commit notes
Date: Thu, 19 Jul 2007 17:20:00 -0700
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Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Alberto Bertogli <albertito@gmail.com>, git@vger.kernel.org,
	Johan Herland <johan@herland.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
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	(Linus Torvalds's message of "Thu, 19 Jul 2007 10:42:18 -0700 (PDT)")
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Linus Torvalds <torvalds@linux-foundation.org> writes:

> On Thu, 19 Jul 2007, Junio C Hamano wrote:
>> > ...
>> > But the real problem of this approach of course is that this is
>> > not reliable and can get a false match.  You can find your
>> > beginning NUL in the SHA-1 part of one entry, and terminating
>> > NUL later in the SHA-1 part of next entry, and you will never
>> > notice.
>
> [ I didn't react to this in your first email, because I thought you were 
>   talking about your "use the rules for the ASCII part", and thought you 
>   talked about how *that* was not reliable and can get a false match). But 
>   it seems that you were actually talking about the NUL character test ]
>
> Nope, wrong.
>
> Why? Because there must always be a NUL *between* different SHA1's. 
> There's *always* a NUL character that precedes a SHA1. So when you have 
> two NUL characters (with no other NUL's between them), you *know* that 
> they cannot be from two different SHA1's. If the first one was from an 
> earlier SHA1, then the second one is *guaranteed* to be the one that 
> happens *before* the next SHA1.
>
> See?

Ok.  As usual, you are more right than I am ;-).