From 33da0b50249e377dabc6511fe1b99f3ada9862b8 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 6 Dec 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-12-06

---
 port/devmnt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/port/devmnt.c b/port/devmnt.c
index 72a86eef6a0f486cbae9f349d4a6a387faba37df..bc59b351a5e60060ab5f044322fc0e7d9ce3975d 100644
--- a/port/devmnt.c
+++ b/port/devmnt.c
@@ -517,7 +517,7 @@ mntopencreate(int type, Chan *c, char *name, int omode, ulong perm)
 	c->offset = 0;
 	c->mode = openmode(omode);
 	c->iounit = r->reply.iounit;
-	if(c->iounit > m->msize-IOHDRSZ)
+	if(c->iounit == 0 || c->iounit > m->msize-IOHDRSZ)
 		c->iounit = m->msize-IOHDRSZ;
 	c->flag |= COPEN;
 	poperror();