From 6aca88663ce711006f87be27f827e37699893303 Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Tue, 18 Jan 2022 19:37:27 +0000
Subject: [PATCH] PRT_make() can just zap the destination dos_partition if the
 source prt has prt_ns == 0 or prt_id == DOSPTYP_UNUSED.

No functional change.
---
 sbin/fdisk/part.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sbin/fdisk/part.c b/sbin/fdisk/part.c
index 3dd5ee8a701..f7525baa104 100644
--- a/sbin/fdisk/part.c
+++ b/sbin/fdisk/part.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: part.c,v 1.110 2021/10/18 20:27:32 krw Exp $	*/
+/*	$OpenBSD: part.c,v 1.111 2022/01/18 19:37:27 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -313,6 +313,11 @@ PRT_make(const struct prt *prt, const uint64_t lba_self, const uint64_t lba_firs
 	uint64_t		off, t;
 	uint32_t		ecyl, scyl;
 
+	if (prt->prt_ns == 0 || prt->prt_id == DOSPTYP_UNUSED) {
+		memset(dp, 0, sizeof(*dp));
+		return;
+	}
+
 	scyl = (prt->prt_scyl > 1023) ? 1023 : prt->prt_scyl;
 	ecyl = (prt->prt_ecyl > 1023) ? 1023 : prt->prt_ecyl;
 
-- 
2.20.1