From: René Scharfe <l.s.r@web.de>
Date: Tue, 1 Nov 2016 08:49:07 +0000 (+0100)
Subject: sha1_name: make wraparound of the index into ring-buffer explicit
X-Git-Tag: v2.11.0-rc1~13^2
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/3e98919a188e36f34c1a20e23ecf2ff1f5da75c9?hp=--cc

sha1_name: make wraparound of the index into ring-buffer explicit

Overflow is defined for unsigned integers, but not for signed ones.
Wrap around explicitly for the new ring-buffer in find_unique_abbrev()
as we did in bb84735c for the ones in sha1_to_hex() and get_pathname(),
thus avoiding signed overflows and getting rid of the magic number 3.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

3e98919a188e36f34c1a20e23ecf2ff1f5da75c9
diff --git a/sha1_name.c b/sha1_name.c
index 36ce9b9f45..45aa26b322 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -474,7 +474,8 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
 {
 	static int bufno;
 	static char hexbuffer[4][GIT_SHA1_HEXSZ + 1];
-	char *hex = hexbuffer[3 & ++bufno];
+	char *hex = hexbuffer[bufno];
+	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
 	find_unique_abbrev_r(hex, sha1, len);
 	return hex;
 }