From 4e2759a68256066ede40431d40a41a57d04776ae Mon Sep 17 00:00:00 2001
From: kamil <kamil@NetBSD.org>
Date: Sat, 16 Jun 2018 18:54:52 +0000
Subject: [PATCH] Do not cause Undefined Behavior in vi(1)

Replace unportable manual calculation of alignof() that causes UB, with
a GCC extension __alignof__.

This fixes a problem reported by UBSan with the MKSANITIZER distribution.
---
 external/bsd/nvi/dist/common/log.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/external/bsd/nvi/dist/common/log.c b/external/bsd/nvi/dist/common/log.c
index fb9df00c64d5..f57e6bdb44ed 100644
--- a/external/bsd/nvi/dist/common/log.c
+++ b/external/bsd/nvi/dist/common/log.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: log.c,v 1.3 2014/01/26 21:43:45 christos Exp $ */
+/*	$NetBSD: log.c,v 1.4 2018/06/16 18:54:52 kamil Exp $ */
 /*-
  * Copyright (c) 1992, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
@@ -16,7 +16,7 @@
 static const char sccsid[] = "Id: log.c,v 10.26 2002/03/02 23:12:13 skimo Exp  (Berkeley) Date: 2002/03/02 23:12:13 ";
 #endif /* not lint */
 #else
-__RCSID("$NetBSD: log.c,v 1.3 2014/01/26 21:43:45 christos Exp $");
+__RCSID("$NetBSD: log.c,v 1.4 2018/06/16 18:54:52 kamil Exp $");
 #endif
 
 #include <sys/types.h>
@@ -90,7 +90,7 @@ typedef struct {
     char    data[sizeof(u_char) /* type */ + sizeof(db_recno_t)];
     CHAR_T  str[1];
 } log_t;
-#define CHAR_T_OFFSET ((char *)(((log_t*)0)->str) - (char *)0)
+#define CHAR_T_OFFSET (__alignof__(log_t))
 
 /*
  * log_init --