implement .DT in terms of .ta; needed for print/ghostview, for example

2 files changed, 20 insertions, 6 deletions

diff --git a/man.7 b/man.7
index 3ce8a4ed..1a79f298 100644
--- a/man.7
+++ b/man.7
@@ -1,4 +1,4 @@
-.\"	$Id: man.7,v 1.134 2017/05/05 15:54:59 schwarze Exp $
+.\"	$Id: man.7,v 1.135 2017/05/07 21:44:49 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2011-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -16,7 +16,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: May 5 2017 $
+.Dd $Mdocdate: May 7 2017 $
 .Dt MAN 7
 .Os
 .Sh NAME
@@ -348,8 +348,12 @@ See also
 and
 .Sx \&IR .
 .Ss \&DT
-Has no effect.
-Included for compatibility.
+Restore the default tabulator positions.
+They are at intervals of 0.5 inches.
+This has no effect unless the tabulator positions were changed with the
+.Xr roff 7
+.Ic \&ta
+request.
 .Ss \&EE
 This is a non-standard GNU extension, included only for compatibility.
 In
diff --git a/man_term.c b/man_term.c
index a96974f9..b902184a 100644
--- a/man_term.c
+++ b/man_term.c
@@ -1,4 +1,4 @@
-/*	$Id: man_term.c,v 1.198 2017/05/07 17:31:45 schwarze Exp $ */
+/*	$Id: man_term.c,v 1.199 2017/05/07 21:44:49 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -68,6 +68,7 @@ static	void		  print_bvspace(struct termp *,
 				const struct roff_node *, int);
 
 static	int		  pre_B(DECL_ARGS);
+static	int		  pre_DT(DECL_ARGS);
 static	int		  pre_HP(DECL_ARGS);
 static	int		  pre_I(DECL_ARGS);
 static	int		  pre_IP(DECL_ARGS);
@@ -117,7 +118,7 @@ static	const struct termact __termacts[MAN_MAX - MAN_TH] = {
 	{ pre_literal, NULL, 0 }, /* fi */
 	{ NULL, NULL, 0 }, /* RE */
 	{ pre_RS, post_RS, 0 }, /* RS */
-	{ pre_ign, NULL, 0 }, /* DT */
+	{ pre_DT, NULL, 0 }, /* DT */
 	{ pre_ign, NULL, MAN_NOTEXT }, /* UC */
 	{ pre_PD, NULL, MAN_NOTEXT }, /* PD */
 	{ pre_ign, NULL, 0 }, /* AT */
@@ -392,6 +393,15 @@ pre_in(DECL_ARGS)
 }
 
 static int
+pre_DT(DECL_ARGS)
+{
+	term_tab_set(p, NULL);
+	term_tab_set(p, "T");
+	term_tab_set(p, ".5i");
+	return 0;
+}
+
+static int
 pre_HP(DECL_ARGS)
 {
 	struct roffsu		 su;