From: Bo Yang <struggleyb.nku@gmail.com>
Date: Sat, 29 May 2010 14:19:14 GMT
Subject: Re: [PATCH v4 4/6] Emit a whole line once a time
Message-ID: <AANLkTin5KJs-3rEbPgLWRnEsTtlkmq7QTb-t0qEKAg78@mail.gmail.com>
In-Reply-To: <7vocfz5x80.fsf@alter.siamese.dyndns.org>

On Sat, May 29, 2010 at 9:10 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Bo Yang <struggleyb.nku@gmail.com> writes:
>
>> Since the graph prefix will be printed when calling
>> emit_line, so the functions should be used to emit a
>> complete line out once a time. No one should call
>> emit_line to just output some strings instead of a
>> complete line.
>> Use a strbuf to compose the whole line, and then
>> call emit_line to output it once.
>
> "once a time" in your title doesn't sound quite right.  I would say "in
> one go" instead.
>
>> Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
>> ---
>>  diff.c |   34 +++++++++++++++++++++++++++++-----
>>  1 files changed, 29 insertions(+), 5 deletions(-)
>>
>> diff --git a/diff.c b/diff.c
>> index 7f2538d..bffaedc 100644
>> --- a/diff.c
>> +++ b/diff.c
>> @@ -370,6 +370,18 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
>>       const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
>>       static const char atat[2] = { '@', '@' };
>>       const char *cp, *ep;
>> +     struct strbuf msgbuf = STRBUF_INIT;
>> +     int org_len = len;
>> +
>> +     /*
>> +      * trailing \r\n
>> +      */
>> +     int i = 1;
>> +     for (; i < 3; i++) {
>> +             if (line[len - i] == '\r' || line[len - i] == '\n') {
>> +                     len --;
>> +             }
>> +     }
>
> I am not very happy with this logic.  The existing code (just outside the
> post-context of this hunk) is being defensive and returns early when len
> is shorter than what we expect, but this new code blindly assumes that len
> is at least 2 bytes long, and also it would eat a line that ends with \r\r.

Hmm, yes, I will move the defensive code upper this check.

> Can the partial line at the end be on this line?  IOW, can line[len-1] be
> different from '\n' in some cases?

I think a line in Macintosh will end with '\r'.

> What's the reason to strip trailing "\r" at the end of the line to begin
> with?

Both '\r' and '\n' will be added back to the strbuf, what I do is
finding the len and make sure the '\r' and \n will not be surround by
the color escape sequence.

-- 
Regards!
Bo
----------------------------
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