Naive implementation of the roff(7) .po (page offset) request.

This clearly works when .po is called on the top level, but might
not be sophisticated enough if people call .po inside indentation-changing
contexts, but i haven't seen that in manual pages (yet :).

6 files changed, 38 insertions, 11 deletions

diff --git a/usr.bin/mandoc/mdoc_man.c b/usr.bin/mandoc/mdoc_man.c
index 61ca0219d5c..d89a4d65f9d 100644
--- a/usr.bin/mandoc/mdoc_man.c
+++ b/usr.bin/mandoc/mdoc_man.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_man.c,v 1.119 2017/06/14 13:00:13 schwarze Exp $ */
+/*	$OpenBSD: mdoc_man.c,v 1.120 2017/06/14 22:50:37 schwarze Exp $ */
 /*
  * Copyright (c) 2011-2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -128,6 +128,7 @@ static	const void_fp roff_manacts[ROFF_MAX] = {
 	pre_ft,		/* ft */
 	pre_onearg,	/* ll */
 	pre_onearg,	/* mc */
+	pre_onearg,	/* po */
 	pre_onearg,	/* rj */
 	pre_sp,		/* sp */
 	pre_ta,		/* ta */
diff --git a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
index 950d0c1435c..7193bdba615 100644
--- a/usr.bin/mandoc/roff.c
+++ b/usr.bin/mandoc/roff.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.c,v 1.183 2017/06/14 19:39:05 schwarze Exp $ */
+/*	$OpenBSD: roff.c,v 1.184 2017/06/14 22:50:37 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -221,8 +221,8 @@ static	enum rofferr	 roff_userdef(ROFF_ARGS);
 
 const char *__roff_name[MAN_MAX + 1] = {
 	"br",		"ce",		"ft",		"ll",
-	"mc",		"rj",		"sp",		"ta",
-	"ti",		NULL,
+	"mc",		"po",		"rj",		"sp",
+	"ta",		"ti",		NULL,
 	"ab",		"ad",		"af",		"aln",
 	"als",		"am",		"am1",		"ami",
 	"ami1",		"as",		"as1",		"asciify",
@@ -263,7 +263,7 @@ const char *__roff_name[MAN_MAX + 1] = {
 	"open",		"opena",	"os",		"output",
 	"padj",		"papersize",	"pc",		"pev",
 	"pi",		"PI",		"pl",		"pm",
-	"pn",		"pnr",		"po",		"ps",
+	"pn",		"pnr",		"ps",
 	"psbb",		"pshape",	"pso",		"ptr",
 	"pvs",		"rchar",	"rd",		"recursionlimit",
 	"return",	"rfschar",	"rhang",
@@ -333,6 +333,7 @@ static	struct roffmac	 roffs[TOKEN_NONE] = {
 	{ roff_onearg, NULL, NULL, 0 },  /* ft */
 	{ roff_onearg, NULL, NULL, 0 },  /* ll */
 	{ roff_onearg, NULL, NULL, 0 },  /* mc */
+	{ roff_onearg, NULL, NULL, 0 },  /* po */
 	{ roff_onearg, NULL, NULL, 0 },  /* rj */
 	{ roff_onearg, NULL, NULL, 0 },  /* sp */
 	{ roff_manyarg, NULL, NULL, 0 },  /* ta */
@@ -498,7 +499,6 @@ static	struct roffmac	 roffs[TOKEN_NONE] = {
 	{ roff_line_ignore, NULL, NULL, 0 },  /* pm */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* pn */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* pnr */
-	{ roff_line_ignore, NULL, NULL, 0 },  /* po */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* ps */
 	{ roff_unsupp, NULL, NULL, 0 },  /* psbb */
 	{ roff_unsupp, NULL, NULL, 0 },  /* pshape */
diff --git a/usr.bin/mandoc/roff.h b/usr.bin/mandoc/roff.h
index c81bec340ed..ae8b99755e4 100644
--- a/usr.bin/mandoc/roff.h
+++ b/usr.bin/mandoc/roff.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.h,v 1.35 2017/06/14 13:00:13 schwarze Exp $	*/
+/*	$OpenBSD: roff.h,v 1.36 2017/06/14 22:50:37 schwarze Exp $	*/
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -77,6 +77,7 @@ enum	roff_tok {
 	ROFF_ft,
 	ROFF_ll,
 	ROFF_mc,
+	ROFF_po,
 	ROFF_rj,
 	ROFF_sp,
 	ROFF_ta,
@@ -245,7 +246,6 @@ enum	roff_tok {
 	ROFF_pm,
 	ROFF_pn,
 	ROFF_pnr,
-	ROFF_po,
 	ROFF_ps,
 	ROFF_psbb,
 	ROFF_pshape,
diff --git a/usr.bin/mandoc/roff_html.c b/usr.bin/mandoc/roff_html.c
index 91de5fc58ba..9674ba9f6cf 100644
--- a/usr.bin/mandoc/roff_html.c
+++ b/usr.bin/mandoc/roff_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff_html.c,v 1.9 2017/06/14 13:00:13 schwarze Exp $ */
+/*	$OpenBSD: roff_html.c,v 1.10 2017/06/14 22:50:37 schwarze Exp $ */
 /*
  * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -38,6 +38,7 @@ static	const roff_html_pre_fp roff_html_pre_acts[ROFF_MAX] = {
 	NULL,  /* ft */
 	NULL,  /* ll */
 	NULL,  /* mc */
+	NULL,  /* po */
 	roff_html_pre_ce,  /* rj */
 	roff_html_pre_sp,  /* sp */
 	NULL,  /* ta */
diff --git a/usr.bin/mandoc/roff_term.c b/usr.bin/mandoc/roff_term.c
index e561b43b57c..a3d9418201b 100644
--- a/usr.bin/mandoc/roff_term.c
+++ b/usr.bin/mandoc/roff_term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff_term.c,v 1.12 2017/06/14 17:50:43 schwarze Exp $ */
+/*	$OpenBSD: roff_term.c,v 1.13 2017/06/14 22:50:37 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -32,6 +32,7 @@ static	void	  roff_term_pre_ce(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ft(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ll(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_mc(ROFF_TERM_ARGS);
+static	void	  roff_term_pre_po(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_sp(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ta(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ti(ROFF_TERM_ARGS);
@@ -42,6 +43,7 @@ static	const roff_term_pre_fp roff_term_pre_acts[ROFF_MAX] = {
 	roff_term_pre_ft,  /* ft */
 	roff_term_pre_ll,  /* ll */
 	roff_term_pre_mc,  /* mc */
+	roff_term_pre_po,  /* po */
 	roff_term_pre_ce,  /* rj */
 	roff_term_pre_sp,  /* sp */
 	roff_term_pre_ta,  /* ta */
@@ -153,6 +155,28 @@ roff_term_pre_mc(ROFF_TERM_ARGS)
 }
 
 static void
+roff_term_pre_po(ROFF_TERM_ARGS)
+{
+	struct roffsu	 su;
+	static int	 po, polast;
+	int		 ponew;
+
+	if (n->child != NULL &&
+	    a2roffsu(n->child->string, &su, SCALE_EM) != NULL) {
+		ponew = term_hen(p, &su);
+		if (*n->child->string == '+' ||
+		    *n->child->string == '-')
+			ponew += po;
+	} else
+		ponew = polast;
+	polast = po;
+	po = ponew;
+
+	ponew = po - polast + (int)p->tcol->offset;
+	p->tcol->offset = ponew > 0 ? ponew : 0;
+}
+
+static void
 roff_term_pre_sp(ROFF_TERM_ARGS)
 {
 	struct roffsu	 su;
diff --git a/usr.bin/mandoc/roff_validate.c b/usr.bin/mandoc/roff_validate.c
index 4f1af9b3695..8a4f5ae6efc 100644
--- a/usr.bin/mandoc/roff_validate.c
+++ b/usr.bin/mandoc/roff_validate.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff_validate.c,v 1.8 2017/06/14 13:00:13 schwarze Exp $ */
+/*	$OpenBSD: roff_validate.c,v 1.9 2017/06/14 22:50:37 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -36,6 +36,7 @@ static	const roff_valid_fp roff_valids[ROFF_MAX] = {
 	roff_valid_ft,  /* ft */
 	NULL,  /* ll */
 	NULL,  /* mc */
+	NULL,  /* po */
 	NULL,  /* rj */
 	NULL,  /* sp */
 	NULL,  /* ta */