# [PATCH] for-each-ref: fix off by one read.

3 messages from 2007-11-12 to 2007-11-13. Participants: Christian Couder, Junio C Hamano.
Thread: https://gitlist.dev/t/10820

## Christian Couder, 2007-11-12 04:37

Subject: [PATCH] for-each-ref: fix off by one read.
Message-ID: <20071112053725.4f0d1940.chriscool@tuxfamily.org>
URL: https://gitlist.dev/e/20071112053725.4f0d1940.chriscool%40tuxfamily.org

```
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 builtin-for-each-ref.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
index 598d4e1..89ea37c 100644
--- a/builtin-for-each-ref.c
+++ b/builtin-for-each-ref.c
@@ -306,7 +306,7 @@ static const char *find_wholine(const char *who, int wholen, const char *buf, un
 		if (!eol)
 			return "";
 		eol++;
-		if (eol[1] == '\n')
+		if (*eol == '\n')
 			return ""; /* end of header */
 		buf = eol;
 	}
-- 
1.5.3.5.577.g4d1b9-dirty

```

## Junio C Hamano, 2007-11-13 00:05

Subject: Re: [PATCH] for-each-ref: fix off by one read.
Message-ID: <7vfxzb1032.fsf@gitster.siamese.dyndns.org>
URL: https://gitlist.dev/e/7vfxzb1032.fsf%40gitster.siamese.dyndns.org
In-Reply-To: <20071112053725.4f0d1940.chriscool@tuxfamily.org>

```
Christian Couder <chriscool@tuxfamily.org> writes:

> diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
> index 598d4e1..89ea37c 100644
> --- a/builtin-for-each-ref.c
> +++ b/builtin-for-each-ref.c
> @@ -306,7 +306,7 @@ static const char *find_wholine(const char *who, int wholen, const char *buf, un
>  		if (!eol)
>  			return "";
>  		eol++;
> -		if (eol[1] == '\n')
> +		if (*eol == '\n')
>  			return ""; /* end of header */
>  		buf = eol;
>  	}

Good eyes.  This would have broken if

 (1) we had a header field that consists of a single character
     and then LF.  We would have mistaken such a line as the end
     of header; or

 (2) we had a commit or a tag that consists solely of header and
     no body.  We would have read past the terminating NUL.

Thanks.

```

## Christian Couder, 2007-11-13 05:15

Subject: Re: [PATCH] for-each-ref: fix off by one read.
Message-ID: <200711130615.54196.chriscool@tuxfamily.org>
URL: https://gitlist.dev/e/200711130615.54196.chriscool%40tuxfamily.org
In-Reply-To: <7vfxzb1032.fsf@gitster.siamese.dyndns.org>

```
Le mardi 13 novembre 2007, Junio C Hamano a écrit :
> Christian Couder <chriscool@tuxfamily.org> writes:
> > diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
> > index 598d4e1..89ea37c 100644
> > --- a/builtin-for-each-ref.c
> > +++ b/builtin-for-each-ref.c
> > @@ -306,7 +306,7 @@ static const char *find_wholine(const char *who,
> > int wholen, const char *buf, un if (!eol)
> >  			return "";
> >  		eol++;
> > -		if (eol[1] == '\n')
> > +		if (*eol == '\n')
> >  			return ""; /* end of header */
> >  		buf = eol;
> >  	}
>
> Good eyes.  

Well, Valgrind found it when I did:

$ valgrind git for-each-ref --format='%(refname)' "refs/tags/*"

> This would have broken if

>  (1) we had a header field that consists of a single character
>      and then LF.  We would have mistaken such a line as the end
>      of header; or
>
>  (2) we had a commit or a tag that consists solely of header and
>      no body.  We would have read past the terminating NUL.

I suspect that the end of the header was not properly detected, so that it 
may have read one byte past a body ending with LF and the terminating NUL.

Christian.

```