===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/mandoc/roff.c,v
retrieving revision 1.225
retrieving revision 1.226
diff -u -r1.225 -r1.226
--- src/usr.bin/mandoc/roff.c	2018/12/18 21:58:41	1.225
+++ src/usr.bin/mandoc/roff.c	2018/12/20 03:38:10	1.226
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.c,v 1.225 2018/12/18 21:58:41 schwarze Exp $ */
+/*	$OpenBSD: roff.c,v 1.226 2018/12/20 03:38:10 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -1586,7 +1586,7 @@
 			switch (cp[1]) {
 			case 'a':
 			case 't':
-				cp[0] = '\t';
+				cp[-pairs] = '\t';
 				/* FALLTHROUGH */
 			case '\\':
 				pairs++;