From e62d4b517b5b4e9b3100bba5eb80514c8e9cd7ae Mon Sep 17 00:00:00 2001
From: Semen Ustimenko <semenu@FreeBSD.org>
Date: Tue, 29 Oct 2002 01:03:44 +0000
Subject: [PATCH] Fix winChkName() to match when the last slot contains nothing
 but the terminating zero (it was treated as length missmatch). The mtools
 create such slots if the name len is the product of 13 (max number of unicode
 chars fitting in directory slot).

MFC after:	1 week
---
 sys/fs/msdosfs/msdosfs_conv.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/sys/fs/msdosfs/msdosfs_conv.c b/sys/fs/msdosfs/msdosfs_conv.c
index 32138c51b6f..7b3591e5766 100644
--- a/sys/fs/msdosfs/msdosfs_conv.c
+++ b/sys/fs/msdosfs/msdosfs_conv.c
@@ -780,7 +780,14 @@ winChkName(un, unlen, wep, chksum, u2w_loaded, u2w, ul_loaded, ul)
 	 */
 	i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
 	un += i;
-	if ((unlen -= i) <= 0)
+	unlen -= i;
+
+	/*
+	 * unlen being zero must not be treated as length missmatch. It is
+	 * possible if the entry is WIN_LAST and contains nothing but the
+	 * terminating 0.
+	 */
+	if (unlen < 0)
 		return -1;
 	if ((wep->weCnt&WIN_LAST) && unlen > WIN_CHARS)
 		return -1;