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

Johannes Schindelin [off-list ref] writes:

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 <redacted>
---
 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