From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?ISO-8859-1?Q?Ren=E9_Scharfe?= <l.s.r@web.de>
Subject: Re: [PATCH 2/2] blame: simplify prepare_lines()
Date: Fri, 13 Jun 2014 23:33:37 +0200
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Cc: Git Mailing List <git@vger.kernel.org>,
	Junio C Hamano <gitster@pobox.com>,
	David Kastrup <dak@gnu.org>
To: Jonathan Nieder <jrnieder@gmail.com>
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Am 13.06.2014 23:13, schrieb Jonathan Nieder:
> Ren=E9 Scharfe wrote:
>
>> -	if (incomplete)
>> -		*lineno++ =3D len;
>> +	*lineno =3D len;
>>
>> -	sb->num_lines =3D num + incomplete;
>> +	sb->num_lines =3D num;
>
> This will always treat whatever comes after the last newline as an
> incomplete line, even if it has zero length.  Is that safe?  (Not a
> rhetorical question --- I haven't looked carefully at the caller.)

There is no need to look at the caller -- the contents of the lineno=20
array is not (intended to be) changed by the patch.

The original code is:

	p =3D memchr(p, '\n', end - p);
	if (p) {
		p++;
		*lineno++ =3D p - buf;
		continue;
	}

Suppose there is no incomplete line.  For the last EOL of a buffer, p=20
points to buf[len - 1] after the memchr call.  Then it is incremented.=20
Then buf + len - buf is written into the last lineno member -- same as=20
after the patch.

Makes sense?

Ren=E9