Re: [VALGRIND PATCH for nth_last patch series] Fix invalid memory access

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 21, 2009, 08:45 UTC
Message-ID: <7vwscpgi7t.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <alpine.DEB.1.00.0901210113500.19014@racer>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 16 quoted lines

>  sha1_name.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/sha1_name.c b/sha1_name.c
> index 4d10705..803f9d2 100644
> --- a/sha1_name.c
> +++ b/sha1_name.c
> @@ -735,7 +735,7 @@ static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
>  	if ((target = strstr(match, " to ")) != NULL) {
>  		len = target - match;
>  		target += 4;
> -		if (target[len] == '\n' && !strncmp(match, target, len))
> +		if (len == strlen(target) && !strncmp(match, target, len))
>  			return 0;
>  	}
>  	else

Actually, I think this patch to a884d0c (sha1_name: tweak @{-N} lookup, 2009-01-17) would make more sense.

-- >8 --
Subject: [PATCH] Simplify parsing branch switching events in reflog

We only accept "checkout: moving from A to B" newer style reflog entries, in order to pick up A. There is no point computing where B begins at after running strstr to locate " to ", nor adding 4 and then subtracting 4 from the same pointer.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sha1_name.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/sha1_name.c b/sha1_name.c
index 38c9f1b..7d95bbb 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -723,17 +723,13 @@ static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
 
 	if (!prefixcmp(message, "checkout: moving from ")) {
 		match = message + strlen("checkout: moving from ");
-		if ((target = strstr(match, " to ")) != NULL)
-			target += 4;
+		target = strstr(match, " to ");
 	}
 
 	if (!match || !target)
 		return 0;
 
-	len = target - match - 4;
-	if (target[len] == '\n' && !strncmp(match, target, len))
-		return 0;
-
+	len = target - match;
 	nth = cb->cnt++ % cb->alloc;
 	strbuf_reset(&cb->buf[nth]);
 	strbuf_add(&cb->buf[nth], match, len);

-- 
1.6.1.281.g16db