# diff --check line number bug

2 messages from 2008-02-15 to 2008-02-16. Participants: Jay Soffian, Junio C Hamano.
Thread: https://gitlist.dev/t/12118

## Jay Soffian, 2008-02-15 20:18

Subject: diff --check line number bug
Message-ID: <76718490802151218s62c4f884u39353b66540b347a@mail.gmail.com>
URL: https://gitlist.dev/e/76718490802151218s62c4f884u39353b66540b347a%40mail.gmail.com

```
% mkdir git-ws
% cd git-ws
% git init
% touch foo
% git add foo
% printf '\n\nline 3 \n\nline 5 \nline 6\n' > foo
% cat -n foo
     1	
     2	
     3	line 3
     4	
     5	line 5
     6	line 6
% sed -ne l foo
$
$
line 3 $
$
line 5 $
line 6$
% git diff --check foo
foo:1: trailing whitespace.
+line 3
foo:2: trailing whitespace.
+line 5
% git version
git version 1.5.4.1.1281.g75df

Apparently somewhere in the bowels of the "Crazy xdl interfaces", empty
lines are skipped over, thus the line number counting in
checkdiff_consume() is off? I dunno, I briefly looked into fixing it but
it didn't seem like a quick fix.

j.

```

## Junio C Hamano, 2008-02-16 04:30

Subject: [PATCH/maint] diff: Fix miscounting of --check output
Message-ID: <7vk5l5frqq.fsf@gitster.siamese.dyndns.org>
URL: https://gitlist.dev/e/7vk5l5frqq.fsf%40gitster.siamese.dyndns.org
In-Reply-To: <76718490802151218s62c4f884u39353b66540b347a@mail.gmail.com>

```
"Jay Soffian" <jaysoffian@gmail.com> writes:

> Apparently somewhere in the bowels of the "Crazy xdl interfaces", empty
> lines are skipped over, thus the line number counting in
> checkdiff_consume() is off? I dunno, I briefly looked into fixing it but
> it didn't seem like a quick fix.

Good catch, thanks.

This is not xdl interface, but simply a miscounting by the user
of xdl interface.  Here is a fix.

-- >8 --
diff: Fix miscounting of --check output

c1795bb (Unify whitespace checking) incorrectly made the
checking function return without incrementing the line numbers
when there is no whitespace problem is found on a '+' line.

This resurrects the earlier behaviour.

Noticed and reported by Jay Soffian.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 diff.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/diff.c b/diff.c
index 047310f..90af600 100644
--- a/diff.c
+++ b/diff.c
@@ -1021,6 +1021,7 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
 	char *err;
 
 	if (line[0] == '+') {
+		data->lineno++;
 		data->status = check_and_emit_line(line + 1, len - 1,
 		    data->ws_rule, NULL, NULL, NULL, NULL);
 		if (!data->status)
@@ -1031,13 +1032,12 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
 		emit_line(set, reset, line, 1);
 		(void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
 		    stdout, set, reset, ws);
-		data->lineno++;
 	} else if (line[0] == ' ')
 		data->lineno++;
 	else if (line[0] == '@') {
 		char *plus = strchr(line, '+');
 		if (plus)
-			data->lineno = strtol(plus, NULL, 10);
+			data->lineno = strtol(plus, NULL, 10) - 1;
 		else
 			die("invalid diff");
 	}

```