From 62be011ebd0374fa9a01e04aeecf31976a4f7414 Mon Sep 17 00:00:00 2001
From: "Andrey A. Chernov" <ache@FreeBSD.org>
Date: Thu, 23 Aug 2001 16:00:27 +0000
Subject: [PATCH] Oops, fix my broken handling of new l_len<0 case

---
 sys/kern/kern_lockf.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sys/kern/kern_lockf.c b/sys/kern/kern_lockf.c
index 7e11d653b239..de8c75daeef6 100644
--- a/sys/kern/kern_lockf.c
+++ b/sys/kern/kern_lockf.c
@@ -133,10 +133,12 @@ lf_advlock(ap, head, size)
 	if (start < 0)
 		return (EINVAL);
 	if (fl->l_len < 0) {
-		start += fl->l_len;
-		if (start <= 0)
+		if (start == 0)
 			return (EINVAL);
 		end = start - 1;
+		start += fl->l_len;
+		if (start < 0)
+			return (EINVAL);
 	} else if (fl->l_len == 0)
 		end = -1;
 	else {