From 9ae693400485454b554ef6d3febec21fb051f32f Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Sun, 2 May 2021 20:07:14 +0000
Subject: [PATCH] Try harder to ensure there are no GPT revenants after
 choosing MBR partitioning.

---
 sbin/fdisk/cmd.c   | 7 ++++---
 sbin/fdisk/fdisk.c | 3 ++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/sbin/fdisk/cmd.c b/sbin/fdisk/cmd.c
index b283116a965..12fb757f559 100644
--- a/sbin/fdisk/cmd.c
+++ b/sbin/fdisk/cmd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cmd.c,v 1.99 2021/01/30 18:16:36 krw Exp $	*/
+/*	$OpenBSD: cmd.c,v 1.100 2021/05/02 20:07:14 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -67,6 +67,7 @@ Xreinit(char *args, struct mbr *mbr)
 		GPT_init();
 		GPT_print("s", 0);
 	} else {
+		memset(&gh, 0, sizeof(gh));
 		MBR_init(mbr);
 		MBR_print(mbr, "s");
 	}
@@ -430,8 +431,8 @@ Xwrite(char *args, struct mbr *mbr)
 			warn("error writing GPT");
 			return (CMD_CONT);
 		}
-	} else if (reinited) {
-		/* Make sure GPT doesn't get in the way. */
+	} else {
+		/* Ensure any on-disk GPT headers are zeroed. */
 		MBR_zapgpt(&dos_mbr, DL_GETDSIZE(&dl) - 1);
 	}
 
diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
index 2d85a7c2a1e..c453a63228e 100644
--- a/sbin/fdisk/fdisk.c
+++ b/sbin/fdisk/fdisk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fdisk.c,v 1.103 2018/04/26 15:55:14 guenther Exp $	*/
+/*	$OpenBSD: fdisk.c,v 1.104 2021/05/02 20:07:14 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -214,6 +214,7 @@ main(int argc, char *argv[])
 			GPT_init();
 			query = "Do you wish to write new GPT?";
 		} else {
+			memset(&gh, 0, sizeof(gh));
 			MBR_init(&initial_mbr);
 			query = "Do you wish to write new MBR and "
 			    "partition table?";
-- 
2.20.1