Subject: Re: [PATCH 2/2] blame: simplify prepare_lines()

From: René Scharfe <[email-masked]>
Date: Fri, 13 Jun 2014 23:33:37 +0200

Am 13.06.2014 23:13, schrieb Jonathan Nieder:
> René Scharfe wrote:
>
>> -	if (incomplete)
>> -		*lineno++ = len;
>> +	*lineno = len;
>>
>> -	sb->num_lines = num + incomplete;
>> +	sb->num_lines = 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 
array is not (intended to be) changed by the patch.

The original code is:

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

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

Makes sense?

René