Introduce the concept of nodes that are semantically transparent:

they are skipped when looking for previous or following high-level
macros.  Examples include roff(7) .ft, .ll, and .ta, mdoc(7) .Sm
and .Tg, and man(7) .DT and .PD.  Use this concept for a variety
of improved decisions in various validators and formatters.

While here,
* remove a few const qualifiers on struct arguments that caused trouble;
* get rid of some more Yoda notation in the vicinity;
* and apply some other stylistic improvements in the vicinity.

I found this class of issues while considering .Tg patches from kn@.

10 files changed, 332 insertions, 285 deletions

diff --git a/usr.bin/mandoc/man_html.c b/usr.bin/mandoc/man_html.c
index 4e66abb36de..589b4114138 100644
--- a/usr.bin/mandoc/man_html.c
+++ b/usr.bin/mandoc/man_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: man_html.c,v 1.128 2020/02/12 21:14:24 schwarze Exp $ */
+/*	$OpenBSD: man_html.c,v 1.129 2020/02/27 01:25:57 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -32,7 +32,7 @@
 #include "main.h"
 
 #define	MAN_ARGS	  const struct roff_meta *man, \
-			  const struct roff_node *n, \
+			  struct roff_node *n, \
 			  struct html *h
 
 struct	man_html_act {
@@ -242,7 +242,7 @@ print_man_node(MAN_ARGS)
 		 * Close the list if no further item of the same type
 		 * follows; otherwise, close the item only.
 		 */
-		if (list_continues(n, n->next) == '\0') {
+		if (list_continues(n, roff_node_next(n)) == '\0') {
 			print_tagq(h, t);
 			t = NULL;
 		}
@@ -443,15 +443,17 @@ list_continues(const struct roff_node *n1, const struct roff_node *n2)
 static int
 man_IP_pre(MAN_ARGS)
 {
-	const struct roff_node	*nn;
+	struct roff_node	*nn;
 	const char		*list_class;
 	enum htmltag		 list_elem, body_elem;
 	char			 list_type;
 
 	nn = n->type == ROFFT_BLOCK ? n : n->parent;
-	if ((list_type = list_continues(nn->prev, nn)) == '\0') {
+	list_type = list_continues(roff_node_prev(nn), nn);
+	if (list_type == '\0') {
 		/* Start a new list. */
-		if ((list_type = list_continues(nn, nn->next)) == '\0')
+		list_type = list_continues(nn, roff_node_next(nn));
+		if (list_type == '\0')
 			list_type = ' ';
 		switch (list_type) {
 		case ' ':
diff --git a/usr.bin/mandoc/man_term.c b/usr.bin/mandoc/man_term.c
index 0a35597877c..33ae377ffb9 100644
--- a/usr.bin/mandoc/man_term.c
+++ b/usr.bin/mandoc/man_term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: man_term.c,v 1.186 2020/01/20 10:29:31 schwarze Exp $ */
+/*	$OpenBSD: man_term.c,v 1.187 2020/02/27 01:25:57 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -62,7 +62,7 @@ static	void		  print_man_head(struct termp *,
 static	void		  print_man_foot(struct termp *,
 				const struct roff_meta *);
 static	void		  print_bvspace(struct termp *,
-				const struct roff_node *, int);
+				struct roff_node *, int);
 
 static	int		  pre_B(DECL_ARGS);
 static	int		  pre_DT(DECL_ARGS);
@@ -203,19 +203,20 @@ terminal_man(void *arg, const struct roff_meta *man)
  * first, print it.
  */
 static void
-print_bvspace(struct termp *p, const struct roff_node *n, int pardist)
+print_bvspace(struct termp *p, struct roff_node *n, int pardist)
 {
-	int	 i;
+	struct roff_node	*nch;
+	int			 i;
 
 	term_newln(p);
 
-	if (n->body != NULL && n->body->child != NULL)
-		if (n->body->child->type == ROFFT_TBL)
-			return;
+	if (n->body != NULL &&
+	    (nch = roff_node_child(n->body)) != NULL &&
+	    nch->type == ROFFT_TBL)
+		return;
 
-	if (n->parent->type == ROFFT_ROOT || n->parent->tok != MAN_RS)
-		if (n->prev == NULL)
-			return;
+	if (n->parent->tok != MAN_RS && roff_node_prev(n) == NULL)
+		return;
 
 	for (i = 0; i < pardist; i++)
 		term_vspace(p);
@@ -681,12 +682,8 @@ pre_SS(DECL_ARGS)
 		 * and after an empty subsection.
 		 */
 
-		do {
-			n = n->prev;
-		} while (n != NULL && n->tok >= MAN_TH &&
-		    man_term_act(n->tok)->flags & MAN_NOTEXT);
-		if (n == NULL || n->type == ROFFT_COMMENT ||
-		    (n->tok == MAN_SS && n->body->child == NULL))
+		if ((n = roff_node_prev(n)) == NULL ||
+		    (n->tok == MAN_SS && roff_node_child(n->body) == NULL))
 			break;
 
 		for (i = 0; i < mt->pardist; i++)
@@ -726,12 +723,8 @@ pre_SH(DECL_ARGS)
 		 * and after an empty section.
 		 */
 
-		do {
-			n = n->prev;
-		} while (n != NULL && n->tok >= MAN_TH &&
-		    man_term_act(n->tok)->flags & MAN_NOTEXT);
-		if (n == NULL || n->type == ROFFT_COMMENT ||
-		    (n->tok == MAN_SH && n->body->child == NULL))
+		if ((n = roff_node_prev(n)) == NULL ||
+		    (n->tok == MAN_SH && roff_node_child(n->body) == NULL))
 			break;
 
 		for (i = 0; i < mt->pardist; i++)
@@ -837,7 +830,7 @@ pre_SY(DECL_ARGS)
 
 	switch (n->type) {
 	case ROFFT_BLOCK:
-		if (n->prev == NULL || n->prev->tok != MAN_SY)
+		if ((nn = roff_node_prev(n)) == NULL || nn->tok != MAN_SY)
 			print_bvspace(p, n, mt->pardist);
 		return 1;
 	case ROFFT_HEAD:
diff --git a/usr.bin/mandoc/mdoc_html.c b/usr.bin/mandoc/mdoc_html.c
index 8a6275f4f5e..cb0c6a82748 100644
--- a/usr.bin/mandoc/mdoc_html.c
+++ b/usr.bin/mandoc/mdoc_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_html.c,v 1.208 2020/01/19 17:59:01 schwarze Exp $ */
+/*	$OpenBSD: mdoc_html.c,v 1.209 2020/02/27 01:25:57 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -50,8 +50,7 @@ static	void		  print_mdoc_head(const struct roff_meta *,
 				struct html *);
 static	void		  print_mdoc_node(MDOC_ARGS);
 static	void		  print_mdoc_nodelist(MDOC_ARGS);
-static	void		  synopsis_pre(struct html *,
-				const struct roff_node *);
+static	void		  synopsis_pre(struct html *, struct roff_node *);
 
 static	void		  mdoc_root_post(const struct roff_meta *,
 				struct html *);
@@ -248,13 +247,15 @@ static const struct mdoc_html_act mdoc_html_acts[MDOC_MAX - MDOC_Dd] = {
  * See the same function in mdoc_term.c for documentation.
  */
 static void
-synopsis_pre(struct html *h, const struct roff_node *n)
+synopsis_pre(struct html *h, struct roff_node *n)
 {
+	struct roff_node *np;
 
-	if (NULL == n->prev || ! (NODE_SYNPRETTY & n->flags))
+	if ((n->flags & NODE_SYNPRETTY) == 0 ||
+	    (np = roff_node_prev(n)) == NULL)
 		return;
 
-	if (n->prev->tok == n->tok &&
+	if (np->tok == n->tok &&
 	    MDOC_Fo != n->tok &&
 	    MDOC_Ft != n->tok &&
 	    MDOC_Fn != n->tok) {
@@ -262,7 +263,7 @@ synopsis_pre(struct html *h, const struct roff_node *n)
 		return;
 	}
 
-	switch (n->prev->tok) {
+	switch (np->tok) {
 	case MDOC_Fd:
 	case MDOC_Fn:
 	case MDOC_Fo:
@@ -623,17 +624,18 @@ mdoc_ss_pre(MDOC_ARGS)
 static int
 mdoc_fl_pre(MDOC_ARGS)
 {
-	char	*id;
+	struct roff_node	*nn;
+	char			*id;
 
 	if ((id = cond_id(n)) != NULL)
 		print_otag(h, TAG_A, "chR", "permalink", id);
 	print_otag(h, TAG_CODE, "ci", "Fl", id);
 
 	print_text(h, "\\-");
-	if (!(n->child == NULL &&
-	    (n->next == NULL ||
-	     n->next->type == ROFFT_TEXT ||
-	     n->next->flags & NODE_LINE)))
+	if (n->child != NULL ||
+	    ((nn = roff_node_next(n)) != NULL &&
+	     nn->type != ROFFT_TEXT &&
+	     (nn->flags & NODE_LINE) == 0))
 		h->flags |= HTML_NOSPACE;
 
 	return 1;
@@ -907,7 +909,7 @@ mdoc_bl_pre(MDOC_ARGS)
 static int
 mdoc_ex_pre(MDOC_ARGS)
 {
-	if (n->prev)
+	if (roff_node_prev(n) != NULL)
 		print_otag(h, TAG_BR, "");
 	return 1;
 }
@@ -984,7 +986,7 @@ mdoc_bd_pre(MDOC_ARGS)
 			continue;
 		if (nn->tok == MDOC_Sh || nn->tok == MDOC_Ss)
 			comp = 1;
-		if (nn->prev != NULL)
+		if (roff_node_prev(nn) != NULL)
 			break;
 	}
 	(void)strlcpy(buf, "Bd", sizeof(buf));
@@ -1096,22 +1098,21 @@ mdoc_fa_pre(MDOC_ARGS)
 		print_otag(h, TAG_VAR, "c", "Fa");
 		return 1;
 	}
-
-	for (nn = n->child; nn; nn = nn->next) {
+	for (nn = n->child; nn != NULL; nn = nn->next) {
 		t = print_otag(h, TAG_VAR, "c", "Fa");
 		print_text(h, nn->string);
 		print_tagq(h, t);
-		if (nn->next) {
+		if (nn->next != NULL) {
 			h->flags |= HTML_NOSPACE;
 			print_text(h, ",");
 		}
 	}
-
-	if (n->child && n->next && n->next->tok == MDOC_Fa) {
+	if (n->child != NULL &&
+	    (nn = roff_node_next(n)) != NULL &&
+	    nn->tok == MDOC_Fa) {
 		h->flags |= HTML_NOSPACE;
 		print_text(h, ",");
 	}
-
 	return 0;
 }
 
@@ -1570,7 +1571,9 @@ mdoc_sy_pre(MDOC_ARGS)
 static int
 mdoc_lb_pre(MDOC_ARGS)
 {
-	if (SEC_LIBRARY == n->sec && NODE_LINE & n->flags && n->prev)
+	if (n->sec == SEC_LIBRARY &&
+	    n->flags & NODE_LINE &&
+	    roff_node_prev(n) != NULL)
 		print_otag(h, TAG_BR, "");
 
 	print_otag(h, TAG_SPAN, "c", "Lb");
@@ -1580,17 +1583,18 @@ mdoc_lb_pre(MDOC_ARGS)
 static int
 mdoc__x_pre(MDOC_ARGS)
 {
-	const char	*cattr;
-	enum htmltag	 t;
+	struct roff_node	*nn;
+	const char		*cattr;
+	enum htmltag		 t;
 
 	t = TAG_SPAN;
 
 	switch (n->tok) {
 	case MDOC__A:
 		cattr = "RsA";
-		if (n->prev && MDOC__A == n->prev->tok)
-			if (NULL == n->next || MDOC__A != n->next->tok)
-				print_text(h, "and");
+		if ((nn = roff_node_prev(n)) != NULL && nn->tok == MDOC__A &&
+		    ((nn = roff_node_next(n)) == NULL || nn->tok != MDOC__A))
+			print_text(h, "and");
 		break;
 	case MDOC__B:
 		t = TAG_I;
@@ -1645,19 +1649,21 @@ mdoc__x_pre(MDOC_ARGS)
 static void
 mdoc__x_post(MDOC_ARGS)
 {
+	struct roff_node *nn;
 
-	if (MDOC__A == n->tok && n->next && MDOC__A == n->next->tok)
-		if (NULL == n->next->next || MDOC__A != n->next->next->tok)
-			if (NULL == n->prev || MDOC__A != n->prev->tok)
-				return;
+	if (n->tok == MDOC__A &&
+	    (nn = roff_node_next(n)) != NULL && nn->tok == MDOC__A &&
+	    ((nn = roff_node_next(nn)) == NULL || nn->tok != MDOC__A) &&
+	    ((nn = roff_node_prev(n)) == NULL || nn->tok != MDOC__A))
+		return;
 
 	/* TODO: %U */
 
-	if (NULL == n->parent || MDOC_Rs != n->parent->tok)
+	if (n->parent == NULL || n->parent->tok != MDOC_Rs)
 		return;
 
 	h->flags |= HTML_NOSPACE;
-	print_text(h, n->next ? "," : ".");
+	print_text(h, roff_node_next(n) ? "," : ".");
 }
 
 static int
diff --git a/usr.bin/mandoc/mdoc_man.c b/usr.bin/mandoc/mdoc_man.c
index 7fde52b78cc..25d59a5a01b 100644
--- a/usr.bin/mandoc/mdoc_man.c
+++ b/usr.bin/mandoc/mdoc_man.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_man.c,v 1.133 2020/02/20 22:55:10 schwarze Exp $ */
+/*	$OpenBSD: mdoc_man.c,v 1.134 2020/02/27 01:25:57 schwarze Exp $ */
 /*
  * Copyright (c) 2011-2020 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -111,7 +111,7 @@ static	int	  pre_sm(DECL_ARGS);
 static	void	  pre_sp(DECL_ARGS);
 static	int	  pre_sect(DECL_ARGS);
 static	int	  pre_sy(DECL_ARGS);
-static	void	  pre_syn(const struct roff_node *);
+static	void	  pre_syn(struct roff_node *);
 static	void	  pre_ta(DECL_ARGS);
 static	int	  pre_vt(DECL_ARGS);
 static	int	  pre_xr(DECL_ARGS);
@@ -648,7 +648,9 @@ print_node(DECL_ARGS)
 	 * Break the line if we were parsed subsequent the current node.
 	 * This makes the page structure be more consistent.
 	 */
-	if (MMAN_spc & outflags && NODE_LINE & n->flags)
+	if (outflags & MMAN_spc &&
+	    n->flags & NODE_LINE &&
+	    !roff_node_transparent(n))
 		outflags |= MMAN_nl;
 
 	act = NULL;
@@ -775,13 +777,20 @@ post_font(DECL_ARGS)
 static void
 post_percent(DECL_ARGS)
 {
+	struct roff_node *np, *nn, *nnn;
 
 	if (mdoc_man_act(n->tok)->pre == pre_em)
 		font_pop();
-	if (n->next) {
-		print_word(",");
-		if (n->prev &&	n->prev->tok == n->tok &&
-				n->next->tok == n->tok)
+
+	if ((nn = roff_node_next(n)) != NULL) {
+		np = roff_node_prev(n);
+		nnn = nn == NULL ? NULL : roff_node_next(nn);
+		if (nn->tok != n->tok ||
+		    (np != NULL && np->tok == n->tok) ||
+		    (nnn != NULL && nnn->tok == n->tok))
+			print_word(",");
+		if (nn->tok == n->tok &&
+		    (nnn == NULL || nnn->tok != n->tok))
 			print_word("and");
 	} else {
 		print_word(".");
@@ -849,13 +858,15 @@ post_sect(DECL_ARGS)
 
 /* See mdoc_term.c, synopsis_pre() for comments. */
 static void
-pre_syn(const struct roff_node *n)
+pre_syn(struct roff_node *n)
 {
+	struct roff_node *np;
 
-	if (NULL == n->prev || ! (NODE_SYNPRETTY & n->flags))
+	if ((n->flags & NODE_SYNPRETTY) == 0 ||
+	    (np = roff_node_prev(n)) == NULL)
 		return;
 
-	if (n->prev->tok == n->tok &&
+	if (np->tok == n->tok &&
 	    MDOC_Ft != n->tok &&
 	    MDOC_Fo != n->tok &&
 	    MDOC_Fn != n->tok) {
@@ -863,7 +874,7 @@ pre_syn(const struct roff_node *n)
 		return;
 	}
 
-	switch (n->prev->tok) {
+	switch (np->tok) {
 	case MDOC_Fd:
 	case MDOC_Fn:
 	case MDOC_Fo:
@@ -939,11 +950,10 @@ static int
 pre_bd(DECL_ARGS)
 {
 	outflags &= ~(MMAN_PP | MMAN_sp | MMAN_br);
-
-	if (DISP_unfilled == n->norm->Bd.type ||
-	    DISP_literal  == n->norm->Bd.type)
+	if (n->norm->Bd.type == DISP_unfilled ||
+	    n->norm->Bd.type == DISP_literal)
 		print_line(".nf", 0);
-	if (0 == n->norm->Bd.comp && NULL != n->parent->prev)
+	if (n->norm->Bd.comp == 0 && roff_node_prev(n->parent) != NULL)
 		outflags |= MMAN_sp;
 	print_offs(n->norm->Bd.offs, 1);
 	return 1;
@@ -975,7 +985,7 @@ post_bd(DECL_ARGS)
 	}
 
 	/* Maybe we are inside an enclosing list? */
-	if (NULL != n->parent->next)
+	if (roff_node_next(n->parent) != NULL)
 		mid_it();
 }
 
@@ -1100,16 +1110,15 @@ post_bl(DECL_ARGS)
 		print_line(".RE", MMAN_nl);
 		assert(Bl_stack_len);
 		Bl_stack_len--;
-		assert(0 == Bl_stack[Bl_stack_len]);
+		assert(Bl_stack[Bl_stack_len] == 0);
 	} else {
 		outflags |= MMAN_PP | MMAN_nl;
 		outflags &= ~(MMAN_sp | MMAN_br);
 	}
 
 	/* Maybe we are inside an enclosing list? */
-	if (NULL != n->parent->next)
+	if (roff_node_next(n->parent) != NULL)
 		mid_it();
-
 }
 
 static void
@@ -1121,7 +1130,6 @@ pre_br(DECL_ARGS)
 static int
 pre_dl(DECL_ARGS)
 {
-
 	print_offs("6n", 0);
 	return 1;
 }
@@ -1129,11 +1137,10 @@ pre_dl(DECL_ARGS)
 static void
 post_dl(DECL_ARGS)
 {
-
 	print_line(".RE", MMAN_nl);
 
 	/* Maybe we are inside an enclosing list? */
-	if (NULL != n->parent->next)
+	if (roff_node_next(n->parent) != NULL)
 		mid_it();
 }
 
@@ -1234,15 +1241,15 @@ pre_fa(DECL_ARGS)
 static void
 post_fa(DECL_ARGS)
 {
+	struct roff_node *nn;
 
-	if (NULL != n->next && MDOC_Fa == n->next->tok)
+	if ((nn = roff_node_next(n)) != NULL && nn->tok == MDOC_Fa)
 		print_word(",");
 }
 
 static int
 pre_fd(DECL_ARGS)
 {
-
 	pre_syn(n);
 	font_push('B');
 	return 1;
@@ -1251,7 +1258,6 @@ pre_fd(DECL_ARGS)
 static void
 post_fd(DECL_ARGS)
 {
-
 	font_pop();
 	outflags |= MMAN_br;
 }
@@ -1259,7 +1265,6 @@ post_fd(DECL_ARGS)
 static int
 pre_fl(DECL_ARGS)
 {
-
 	font_push('B');
 	print_word("\\-");
 	if (n->child != NULL)
@@ -1270,12 +1275,13 @@ pre_fl(DECL_ARGS)
 static void
 post_fl(DECL_ARGS)
 {
+	struct roff_node *nn;
 
 	font_pop();
-	if (!(n->child != NULL ||
-	    n->next == NULL ||
-	    n->next->type == ROFFT_TEXT ||
-	    n->next->flags & NODE_LINE))
+	if (n->child == NULL &&
+	    ((nn = roff_node_next(n)) != NULL &&
+	    nn->type != ROFFT_TEXT &&
+	    (nn->flags & NODE_LINE) == 0))
 		outflags &= ~MMAN_spc;
 }
 
@@ -1418,9 +1424,9 @@ pre_it(DECL_ARGS)
 	case ROFFT_HEAD:
 		outflags |= MMAN_PP | MMAN_nl;
 		bln = n->parent->parent;
-		if (0 == bln->norm->Bl.comp ||
-		    (NULL == n->parent->prev &&
-		     NULL == bln->parent->prev))
+		if (bln->norm->Bl.comp == 0 ||
+		    (n->parent->prev == NULL &&
+		     roff_node_prev(bln->parent) == NULL))
 			outflags |= MMAN_sp;
 		outflags &= ~MMAN_br;
 		switch (bln->norm->Bl.type) {
@@ -1632,17 +1638,22 @@ pre_nm(DECL_ARGS)
 {
 	char	*name;
 
-	if (n->type == ROFFT_BLOCK) {
+	switch (n->type) {
+	case ROFFT_BLOCK:
 		outflags |= MMAN_Bk;
 		pre_syn(n);
-	}
-	if (n->type != ROFFT_ELEM && n->type != ROFFT_HEAD)
 		return 1;
+	case ROFFT_HEAD:
+	case ROFFT_ELEM:
+		break;
+	default:
+		return 1;
+	}
 	name = n->child == NULL ? NULL : n->child->string;
-	if (NULL == name)
+	if (name == NULL)
 		return 0;
 	if (n->type == ROFFT_HEAD) {
-		if (NULL == n->parent->prev)
+		if (roff_node_prev(n->parent) == NULL)
 			outflags |= MMAN_sp;
 		print_block(".HP", 0);
 		printf(" %dn", man_strlen(name) + 1);
diff --git a/usr.bin/mandoc/mdoc_markdown.c b/usr.bin/mandoc/mdoc_markdown.c
index 22b46978320..fe87440b5c1 100644
--- a/usr.bin/mandoc/mdoc_markdown.c
+++ b/usr.bin/mandoc/mdoc_markdown.c
@@ -1,6 +1,6 @@
-/*	$OpenBSD: mdoc_markdown.c,v 1.33 2020/02/20 00:29:10 schwarze Exp $ */
+/*	$OpenBSD: mdoc_markdown.c,v 1.34 2020/02/27 01:25:57 schwarze Exp $ */
 /*
- * Copyright (c) 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2017, 2018, 2020 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -310,7 +310,9 @@ md_node(struct roff_node *n)
 
 	if (outflags & MD_nonl)
 		outflags &= ~(MD_nl | MD_sp);
-	else if (outflags & MD_spc && n->flags & NODE_LINE)
+	else if (outflags & MD_spc &&
+	     n->flags & NODE_LINE &&
+	     !roff_node_transparent(n))
 		outflags |= MD_nl;
 
 	act = NULL;
@@ -787,14 +789,17 @@ md_post_word(struct roff_node *n)
 static void
 md_post_pc(struct roff_node *n)
 {
+	struct roff_node *nn;
+
 	md_post_raw(n);
 	if (n->parent->tok != MDOC_Rs)
 		return;
-	if (n->next != NULL) {
+
+	if ((nn = roff_node_next(n)) != NULL) {
 		md_word(",");
-		if (n->prev != NULL &&
-		    n->prev->tok == n->tok &&
-		    n->next->tok == n->tok)
+		if (nn->tok == n->tok &&
+		    (nn = roff_node_prev(n)) != NULL &&
+		    nn->tok == n->tok)
 			md_word("and");
 	} else {
 		md_word(".");
@@ -811,10 +816,13 @@ md_pre_skip(struct roff_node *n)
 static void
 md_pre_syn(struct roff_node *n)
 {
-	if (n->prev == NULL || ! (n->flags & NODE_SYNPRETTY))
+	struct roff_node *np;
+
+	if ((n->flags & NODE_SYNPRETTY) == 0 ||
+	    (np = roff_node_prev(n)) == NULL)
 		return;
 
-	if (n->prev->tok == n->tok &&
+	if (np->tok == n->tok &&
 	    n->tok != MDOC_Ft &&
 	    n->tok != MDOC_Fo &&
 	    n->tok != MDOC_Fn) {
@@ -822,7 +830,7 @@ md_pre_syn(struct roff_node *n)
 		return;
 	}
 
-	switch (n->prev->tok) {
+	switch (np->tok) {
 	case MDOC_Fd:
 	case MDOC_Fn:
 	case MDOC_Fo:
@@ -1053,7 +1061,9 @@ md_pre_Fa(struct roff_node *n)
 static void
 md_post_Fa(struct roff_node *n)
 {
-	if (n->next != NULL && n->next->tok == MDOC_Fa)
+	struct roff_node *nn;
+
+	if ((nn = roff_node_next(n)) != NULL && nn->tok == MDOC_Fa)
 		md_word(",");
 }
 
@@ -1075,9 +1085,11 @@ md_post_Fd(struct roff_node *n)
 static void
 md_post_Fl(struct roff_node *n)
 {
+	struct roff_node *nn;
+
 	md_post_raw(n);
-	if (n->child == NULL && n->next != NULL &&
-	    n->next->type != ROFFT_TEXT && !(n->next->flags & NODE_LINE))
+	if (n->child == NULL && (nn = roff_node_next(n)) != NULL &&
+	    nn->type != ROFFT_TEXT && (nn->flags & NODE_LINE) == 0)
 		outflags &= ~MD_spc;
 }
 
diff --git a/usr.bin/mandoc/mdoc_term.c b/usr.bin/mandoc/mdoc_term.c
index 5e7412e124b..dab449d9da4 100644
--- a/usr.bin/mandoc/mdoc_term.c
+++ b/usr.bin/mandoc/mdoc_term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_term.c,v 1.275 2020/01/20 10:29:31 schwarze Exp $ */
+/*	$OpenBSD: mdoc_term.c,v 1.276 2020/02/27 01:25:57 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2012-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -52,14 +52,12 @@ struct	mdoc_term_act {
 static	int	  a2width(const struct termp *, const char *);
 
 static	void	  print_bvspace(struct termp *,
-			const struct roff_node *,
-			const struct roff_node *);
+			struct roff_node *, struct roff_node *);
 static	void	  print_mdoc_node(DECL_ARGS);
 static	void	  print_mdoc_nodelist(DECL_ARGS);
 static	void	  print_mdoc_head(struct termp *, const struct roff_meta *);
 static	void	  print_mdoc_foot(struct termp *, const struct roff_meta *);
-static	void	  synopsis_pre(struct termp *,
-			const struct roff_node *);
+static	void	  synopsis_pre(struct termp *, struct roff_node *);
 
 static	void	  termp____post(DECL_ARGS);
 static	void	  termp__t_post(DECL_ARGS);
@@ -580,29 +578,20 @@ a2width(const struct termp *p, const char *v)
  * too.
  */
 static void
-print_bvspace(struct termp *p,
-	const struct roff_node *bl,
-	const struct roff_node *n)
+print_bvspace(struct termp *p, struct roff_node *bl, struct roff_node *n)
 {
-	const struct roff_node	*nn;
-
-	assert(n);
+	struct roff_node *nn;
 
 	term_newln(p);
 
-	if (MDOC_Bd == bl->tok && bl->norm->Bd.comp)
-		return;
-	if (MDOC_Bl == bl->tok && bl->norm->Bl.comp)
+	if ((bl->tok == MDOC_Bd && bl->norm->Bd.comp) ||
+	    (bl->tok == MDOC_Bl && bl->norm->Bl.comp))
 		return;
 
 	/* Do not vspace directly after Ss/Sh. */
 
 	nn = n;
-	while (nn->prev != NULL &&
-	    (nn->prev->type == ROFFT_COMMENT ||
-	     nn->prev->flags & NODE_NOPRT))
-		nn = nn->prev;
-	while (nn->prev == NULL) {
+	while (roff_node_prev(nn) == NULL) {
 		do {
 			nn = nn->parent;
 			if (nn->type == ROFFT_ROOT)
@@ -615,22 +604,18 @@ print_bvspace(struct termp *p,
 			break;
 	}
 
-	/* A `-column' does not assert vspace within the list. */
-
-	if (MDOC_Bl == bl->tok && LIST_column == bl->norm->Bl.type)
-		if (n->prev && MDOC_It == n->prev->tok)
-			return;
-
-	/* A `-diag' without body does not vspace. */
-
-	if (MDOC_Bl == bl->tok && LIST_diag == bl->norm->Bl.type)
-		if (n->prev && MDOC_It == n->prev->tok) {
-			assert(n->prev->body);
-			if (NULL == n->prev->body->child)
-				return;
-		}
+	/*
+	 * No vertical space after:
+	 * items in .Bl -column
+	 * items without a body in .Bl -diag
+	 */
 
-	term_vspace(p);
+	if (bl->tok != MDOC_Bl ||
+	    n->prev == NULL || n->prev->tok != MDOC_It ||
+	    (bl->norm->Bl.type != LIST_column &&
+	     (bl->norm->Bl.type != LIST_diag ||
+	      n->prev->body->child != NULL)))
+		term_vspace(p);
 }
 
 
@@ -1041,15 +1026,16 @@ termp_nm_post(DECL_ARGS)
 static int
 termp_fl_pre(DECL_ARGS)
 {
+	struct roff_node *nn;
 
 	termp_tag_pre(p, pair, meta, n);
 	term_fontpush(p, TERMFONT_BOLD);
 	term_word(p, "\\-");
 
-	if (!(n->child == NULL &&
-	    (n->next == NULL ||
-	     n->next->type == ROFFT_TEXT ||
-	     n->next->flags & NODE_LINE)))
+	if (n->child != NULL ||
+	    ((nn = roff_node_next(n)) != NULL &&
+	     nn->type != ROFFT_TEXT &&
+	     (nn->flags & NODE_LINE) == 0))
 		p->flags |= TERMP_NOSPACE;
 
 	return 1;
@@ -1058,10 +1044,11 @@ termp_fl_pre(DECL_ARGS)
 static int
 termp__a_pre(DECL_ARGS)
 {
+	struct roff_node *nn;
 
-	if (n->prev && MDOC__A == n->prev->tok)
-		if (NULL == n->next || MDOC__A != n->next->tok)
-			term_word(p, "and");
+	if ((nn = roff_node_prev(n)) != NULL && nn->tok == MDOC__A &&
+	    ((nn = roff_node_next(n)) == NULL || nn->tok != MDOC__A))
+		term_word(p, "and");
 
 	return 1;
 }
@@ -1102,10 +1089,9 @@ termp_ns_pre(DECL_ARGS)
 static int
 termp_rs_pre(DECL_ARGS)
 {
-
 	if (SEC_SEE_ALSO != n->sec)
 		return 1;
-	if (n->type == ROFFT_BLOCK && n->prev != NULL)
+	if (n->type == ROFFT_BLOCK && roff_node_prev(n) != NULL)
 		term_vspace(p);
 	return 1;
 }
@@ -1179,13 +1165,12 @@ termp_xr_pre(DECL_ARGS)
  * macro combos).
  */
 static void
-synopsis_pre(struct termp *p, const struct roff_node *n)
+synopsis_pre(struct termp *p, struct roff_node *n)
 {
-	/*
-	 * Obviously, if we're not in a SYNOPSIS or no prior macros
-	 * exist, do nothing.
-	 */
-	if (NULL == n->prev || ! (NODE_SYNPRETTY & n->flags))
+	struct roff_node	*np;
+
+	if ((n->flags & NODE_SYNPRETTY) == 0 ||
+	    (np = roff_node_prev(n)) == NULL)
 		return;
 
 	/*
@@ -1193,7 +1178,7 @@ synopsis_pre(struct termp *p, const struct roff_node *n)
 	 * newline and return.  UNLESS we're `Fo', `Fn', `Fn', in which
 	 * case we soldier on.
 	 */
-	if (n->prev->tok == n->tok &&
+	if (np->tok == n->tok &&
 	    MDOC_Ft != n->tok &&
 	    MDOC_Fo != n->tok &&
 	    MDOC_Fn != n->tok) {
@@ -1206,7 +1191,7 @@ synopsis_pre(struct termp *p, const struct roff_node *n)
 	 * another (or Fn/Fo, which we've let slip through) then assert
 	 * vertical space, else only newline and move on.
 	 */
-	switch (n->prev->tok) {
+	switch (np->tok) {
 	case MDOC_Fd:
 	case MDOC_Fn:
 	case MDOC_Fo:
@@ -1215,7 +1200,7 @@ synopsis_pre(struct termp *p, const struct roff_node *n)
 		term_vspace(p);
 		break;
 	case MDOC_Ft:
-		if (MDOC_Fn != n->tok && MDOC_Fo != n->tok) {
+		if (n->tok != MDOC_Fn && n->tok != MDOC_Fo) {
 			term_vspace(p);
 			break;
 		}
@@ -1269,6 +1254,7 @@ termp_fd_post(DECL_ARGS)
 static int
 termp_sh_pre(DECL_ARGS)
 {
+	struct roff_node	*np;
 
 	switch (n->type) {
 	case ROFFT_BLOCK:
@@ -1276,10 +1262,9 @@ termp_sh_pre(DECL_ARGS)
 		 * Vertical space before sections, except
 		 * when the previous section was empty.
 		 */
-		if (n->prev == NULL ||
-		    n->prev->tok != MDOC_Sh ||
-		    (n->prev->body != NULL &&
-		     n->prev->body->child != NULL))
+		if ((np = roff_node_prev(n)) == NULL ||
+		    np->tok != MDOC_Sh ||
+		    (np->body != NULL && np->body->child != NULL))
 			term_vspace(p);
 		break;
 	case ROFFT_HEAD:
@@ -1430,19 +1415,22 @@ termp_fa_pre(DECL_ARGS)
 		term_fontpush(p, TERMFONT_UNDER);
 		return 1;
 	}
-
-	for (nn = n->child; nn; nn = nn->next) {
+	for (nn = n->child; nn != NULL; nn = nn->next) {
 		term_fontpush(p, TERMFONT_UNDER);
 		p->flags |= TERMP_NBRWORD;
 		term_word(p, nn->string);
 		term_fontpop(p);
-
-		if (nn->next || (n->next && n->next->tok == MDOC_Fa)) {
+		if (nn->next != NULL) {
 			p->flags |= TERMP_NOSPACE;
 			term_word(p, ",");
 		}
 	}
-
+	if (n->child != NULL &&
+	    (nn = roff_node_next(n)) != NULL &&
+	    nn->tok == MDOC_Fa) {
+		p->flags |= TERMP_NOSPACE;
+		term_word(p, ",");
+	}
 	return 0;
 }
 
@@ -1522,24 +1510,18 @@ termp_xx_post(DECL_ARGS)
 static void
 termp_pf_post(DECL_ARGS)
 {
-
-	if ( ! (n->next == NULL || n->next->flags & NODE_LINE))
+	if (n->next != NULL && (n->next->flags & NODE_LINE) == 0)
 		p->flags |= TERMP_NOSPACE;
 }
 
 static int
 termp_ss_pre(DECL_ARGS)
 {
-	struct roff_node *nn;
-
 	switch (n->type) {
 	case ROFFT_BLOCK:
-		term_newln(p);
-		for (nn = n->prev; nn != NULL; nn = nn->prev)
-			if (nn->type != ROFFT_COMMENT &&
-			    (nn->flags & NODE_NOPRT) == 0)
-				break;
-		if (nn != NULL)
+		if (roff_node_prev(n) == NULL)
+			term_newln(p);
+		else
 			term_vspace(p);
 		break;
 	case ROFFT_HEAD:
@@ -1555,14 +1537,12 @@ termp_ss_pre(DECL_ARGS)
 	default:
 		break;
 	}
-
 	return 1;
 }
 
 static void
 termp_ss_post(DECL_ARGS)
 {
-
 	if (n->type == ROFFT_HEAD || n->type == ROFFT_BODY)
 		term_newln(p);
 }
@@ -1890,24 +1870,26 @@ termp_ap_pre(DECL_ARGS)
 static void
 termp____post(DECL_ARGS)
 {
+	struct roff_node *nn;
 
 	/*
 	 * Handle lists of authors.  In general, print each followed by
 	 * a comma.  Don't print the comma if there are only two
 	 * authors.
 	 */
-	if (MDOC__A == n->tok && n->next && MDOC__A == n->next->tok)
-		if (NULL == n->next->next || MDOC__A != n->next->next->tok)
-			if (NULL == n->prev || MDOC__A != n->prev->tok)
-				return;
+	if (n->tok == MDOC__A &&
+	    (nn = roff_node_next(n)) != NULL && nn->tok == MDOC__A &&
+	    ((nn = roff_node_next(nn)) == NULL || nn->tok != MDOC__A) &&
+	    ((nn = roff_node_prev(n)) == NULL || nn->tok != MDOC__A))
+		return;
 
 	/* TODO: %U. */
 
-	if (NULL == n->parent || MDOC_Rs != n->parent->tok)
+	if (n->parent == NULL || n->parent->tok != MDOC_Rs)
 		return;
 
 	p->flags |= TERMP_NOSPACE;
-	if (NULL == n->next) {
+	if (roff_node_next(n) == NULL) {
 		term_word(p, ".");
 		p->flags |= TERMP_SENTENCE;
 	} else
diff --git a/usr.bin/mandoc/mdoc_validate.c b/usr.bin/mandoc/mdoc_validate.c
index b7ae573a127..902294e8d79 100644
--- a/usr.bin/mandoc/mdoc_validate.c
+++ b/usr.bin/mandoc/mdoc_validate.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mdoc_validate.c,v 1.292 2020/01/19 17:59:01 schwarze Exp $ */
+/*	$OpenBSD: mdoc_validate.c,v 1.293 2020/02/27 01:25:58 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -1745,8 +1745,7 @@ post_bl_head(POST_ARGS)
 static void
 post_bl(POST_ARGS)
 {
-	struct roff_node	*nparent, *nprev; /* of the Bl block */
-	struct roff_node	*nblock, *nbody;  /* of the Bl */
+	struct roff_node	*nbody;           /* of the Bl */
 	struct roff_node	*nchild, *nnext;  /* of the Bl body */
 	const char		*prev_Er;
 	int			 order;
@@ -1767,88 +1766,73 @@ post_bl(POST_ARGS)
 	if (nbody->end != ENDBODY_NOT)
 		return;
 
-	nchild = nbody->child;
-	if (nchild == NULL) {
-		mandoc_msg(MANDOCERR_BLK_EMPTY,
-		    nbody->line, nbody->pos, "Bl");
-		return;
+	/*
+	 * Up to the first item, move nodes before the list,
+	 * but leave transparent nodes where they are
+	 * if they precede an item.
+	 * The next non-transparent node is kept in nchild.
+	 * It only needs to be updated after a non-transparent
+	 * node was moved out, and at the very beginning
+	 * when no node at all was moved yet.
+	 */
+
+	nchild = mdoc->last;
+	for (;;) {
+		if (nchild == mdoc->last)
+			nchild = roff_node_child(nbody);
+		if (nchild == NULL) {
+			mdoc->last = nbody;
+			mandoc_msg(MANDOCERR_BLK_EMPTY,
+			    nbody->line, nbody->pos, "Bl");
+			return;
+		}
+		if (nchild->tok == MDOC_It) {
+			mdoc->last = nbody;
+			break;
+		}
+		mandoc_msg(MANDOCERR_BL_MOVE, nbody->child->line,
+		    nbody->child->pos, "%s", roff_name[nbody->child->tok]);
+		if (nbody->parent->prev == NULL) {
+			mdoc->last = nbody->parent->parent;
+			mdoc->next = ROFF_NEXT_CHILD;
+		} else {
+			mdoc->last = nbody->parent->prev;
+			mdoc->next = ROFF_NEXT_SIBLING;
+		}
+		roff_node_relink(mdoc, nbody->child);
 	}
+
+	/*
+	 * We have reached the first item,
+	 * so moving nodes out is no longer possible.
+	 * But in .Bl -column, the first rows may be implicit,
+	 * that is, they may not start with .It macros.
+	 * Such rows may be followed by nodes generated on the
+	 * roff level, for example .TS.
+	 * Wrap such roff nodes into an implicit row.
+	 */
+
 	while (nchild != NULL) {
-		nnext = nchild->next;
-		if (nchild->tok == MDOC_It ||
-		    ((nchild->tok == MDOC_Sm || nchild->tok == MDOC_Tg) &&
-		     nnext != NULL && nnext->tok == MDOC_It)) {
-			nchild = nnext;
+		if (nchild->tok == MDOC_It) {
+			nchild = roff_node_next(nchild);
 			continue;
 		}
-
-		/*
-		 * In .Bl -column, the first rows may be implicit,
-		 * that is, they may not start with .It macros.
-		 * Such rows may be followed by nodes generated on the
-		 * roff level, for example .TS, which cannot be moved
-		 * out of the list.  In that case, wrap such roff nodes
-		 * into an implicit row.
-		 */
-
-		if (nchild->prev != NULL) {
-			mdoc->last = nchild;
-			mdoc->next = ROFF_NEXT_SIBLING;
-			roff_block_alloc(mdoc, nchild->line,
-			    nchild->pos, MDOC_It);
-			roff_head_alloc(mdoc, nchild->line,
-			    nchild->pos, MDOC_It);
+		nnext = nchild->next;
+		mdoc->last = nchild->prev;
+		mdoc->next = ROFF_NEXT_SIBLING;
+		roff_block_alloc(mdoc, nchild->line, nchild->pos, MDOC_It);
+		roff_head_alloc(mdoc, nchild->line, nchild->pos, MDOC_It);
+		mdoc->next = ROFF_NEXT_SIBLING;
+		roff_body_alloc(mdoc, nchild->line, nchild->pos, MDOC_It);
+		while (nchild->tok != MDOC_It) {
+			roff_node_relink(mdoc, nchild);
+			if (nnext == NULL)
+				break;
+			nchild = nnext;
+			nnext = nchild->next;
 			mdoc->next = ROFF_NEXT_SIBLING;
-			roff_body_alloc(mdoc, nchild->line,
-			    nchild->pos, MDOC_It);
-			while (nchild->tok != MDOC_It) {
-				roff_node_relink(mdoc, nchild);
-				if ((nchild = nnext) == NULL)
-					break;
-				nnext = nchild->next;
-				mdoc->next = ROFF_NEXT_SIBLING;
-			}
-			mdoc->last = nbody;
-			continue;
 		}
-
-		mandoc_msg(MANDOCERR_BL_MOVE, nchild->line, nchild->pos,
-		    "%s", roff_name[nchild->tok]);
-
-		/*
-		 * Move the node out of the Bl block.
-		 * First, collect all required node pointers.
-		 */
-
-		nblock  = nbody->parent;
-		nprev   = nblock->prev;
-		nparent = nblock->parent;
-
-		/*
-		 * Unlink this child.
-		 */
-
-		nbody->child = nnext;
-		if (nnext == NULL)
-			nbody->last  = NULL;
-		else
-			nnext->prev = NULL;
-
-		/*
-		 * Relink this child.
-		 */
-
-		nchild->parent = nparent;
-		nchild->prev   = nprev;
-		nchild->next   = nblock;
-
-		nblock->prev = nchild;
-		if (nprev == NULL)
-			nparent->child = nchild;
-		else
-			nprev->next = nchild;
-
-		nchild = nnext;
+		mdoc->last = nbody;
 	}
 
 	if (mdoc->meta.os_e != MANDOC_OS_NETBSD)
@@ -2485,20 +2469,20 @@ post_ignpar(POST_ARGS)
 static void
 post_prevpar(POST_ARGS)
 {
-	struct roff_node *n;
+	struct roff_node *n, *np;
 
 	n = mdoc->last;
-	if (NULL == n->prev)
-		return;
 	if (n->type != ROFFT_ELEM && n->type != ROFFT_BLOCK)
 		return;
+	if ((np = roff_node_prev(n)) == NULL)
+		return;
 
 	/*
 	 * Don't allow `Pp' prior to a paragraph-type
 	 * block: `Pp' or non-compact `Bd' or `Bl'.
 	 */
 
-	if (n->prev->tok != MDOC_Pp && n->prev->tok != ROFF_br)
+	if (np->tok != MDOC_Pp && np->tok != ROFF_br)
 		return;
 	if (n->tok == MDOC_Bl && n->norm->Bl.comp)
 		return;
@@ -2507,9 +2491,9 @@ post_prevpar(POST_ARGS)
 	if (n->tok == MDOC_It && n->parent->norm->Bl.comp)
 		return;
 
-	mandoc_msg(MANDOCERR_PAR_SKIP, n->prev->line, n->prev->pos,
-	    "%s before %s", roff_name[n->prev->tok], roff_name[n->tok]);
-	roff_node_delete(mdoc, n->prev);
+	mandoc_msg(MANDOCERR_PAR_SKIP, np->line, np->pos,
+	    "%s before %s", roff_name[np->tok], roff_name[n->tok]);
+	roff_node_delete(mdoc, np);
 }
 
 static void
diff --git a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
index 35eec08824c..9a8e77a9893 100644
--- a/usr.bin/mandoc/roff.c
+++ b/usr.bin/mandoc/roff.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.c,v 1.241 2020/01/19 17:59:01 schwarze Exp $ */
+/*	$OpenBSD: roff.c,v 1.242 2020/02/27 01:25:58 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -1112,6 +1112,59 @@ roff_node_delete(struct roff_man *man, struct roff_node *n)
 	roff_node_free(n);
 }
 
+int
+roff_node_transparent(struct roff_node *n)
+{
+	if (n == NULL)
+		return 0;
+	if (n->type == ROFFT_COMMENT || n->flags & NODE_NOPRT)
+		return 1;
+	switch (n->tok) {
+	case ROFF_ft:
+	case ROFF_ll:
+	case ROFF_mc:
+	case ROFF_po:
+	case ROFF_ta:
+	case MDOC_Db:
+	case MDOC_Es:
+	case MDOC_Sm:
+	case MDOC_Tg:
+	case MAN_DT:
+	case MAN_UC:
+	case MAN_PD:
+	case MAN_AT:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+struct roff_node *
+roff_node_child(struct roff_node *n)
+{
+	for (n = n->child; roff_node_transparent(n); n = n->next)
+		continue;
+	return n;
+}
+
+struct roff_node *
+roff_node_prev(struct roff_node *n)
+{
+	do {
+		n = n->prev;
+	} while (roff_node_transparent(n));
+	return n;
+}
+
+struct roff_node *
+roff_node_next(struct roff_node *n)
+{
+	do {
+		n = n->next;
+	} while (roff_node_transparent(n));
+	return n;
+}
+
 void
 deroff(char **dest, const struct roff_node *n)
 {
diff --git a/usr.bin/mandoc/roff.h b/usr.bin/mandoc/roff.h
index 1479a12688f..24c0e39bc1f 100644
--- a/usr.bin/mandoc/roff.h
+++ b/usr.bin/mandoc/roff.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.h,v 1.52 2020/01/19 17:59:01 schwarze Exp $	*/
+/*	$OpenBSD: roff.h,v 1.53 2020/02/27 01:25:58 schwarze Exp $	*/
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
@@ -549,5 +549,9 @@ struct	roff_meta {
 extern	const char *const *roff_name;
 
 
-int		 arch_valid(const char *, enum mandoc_os);
-void		 deroff(char **, const struct roff_node *);
+int		  arch_valid(const char *, enum mandoc_os);
+void		  deroff(char **, const struct roff_node *);
+struct roff_node *roff_node_child(struct roff_node *);
+struct roff_node *roff_node_next(struct roff_node *);
+struct roff_node *roff_node_prev(struct roff_node *);
+int		  roff_node_transparent(struct roff_node *);
diff --git a/usr.bin/mandoc/roff_validate.c b/usr.bin/mandoc/roff_validate.c
index 5b6686c2d4c..6fa4f334456 100644
--- a/usr.bin/mandoc/roff_validate.c
+++ b/usr.bin/mandoc/roff_validate.c
@@ -1,6 +1,6 @@
-/*	$OpenBSD: roff_validate.c,v 1.18 2018/12/31 09:02:30 schwarze Exp $ */
+/*	$OpenBSD: roff_validate.c,v 1.19 2020/02/27 01:25:58 schwarze Exp $ */
 /*
- * Copyright (c) 2010, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010, 2017, 2018, 2020 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -75,7 +75,7 @@ roff_valid_br(ROFF_VALID_ARGS)
 		return;
 	}
 
-	if ((np = n->prev) == NULL)
+	if ((np = roff_node_prev(n)) == NULL)
 		return;
 
 	switch (np->tok) {
@@ -129,7 +129,7 @@ roff_valid_sp(ROFF_VALID_ARGS)
 {
 	struct roff_node	*np;
 
-	if ((np = n->prev) == NULL)
+	if ((np = roff_node_prev(n)) == NULL)
 		return;
 
 	switch (np->tok) {