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@.

4 files changed, 49 insertions, 3 deletions

diff --git a/regress/man/TP/Makefile b/regress/man/TP/Makefile
index 2fc1074f..ca2475b0 100644
--- a/regress/man/TP/Makefile
+++ b/regress/man/TP/Makefile
@@ -1,9 +1,9 @@
-# $OpenBSD: Makefile,v 1.15 2019/01/06 04:41:15 schwarze Exp $
+# $OpenBSD: Makefile,v 1.16 2020/02/27 01:25:58 schwarze Exp $
 
 REGRESS_TARGETS	 = badarg broken double eof fill indent literal longhead
-REGRESS_TARGETS	+= macrotag manyargs sameline spacing width
+REGRESS_TARGETS	+= macrotag manyargs sameline spacing vert width
 LINT_TARGETS	 = broken double eof
-HTML_TARGETS	 = literal
+HTML_TARGETS	 = literal vert
 
 # groff-1.22.3 defects:
 # - If .TP precedes .RE, the latter does not properly reset indentation.
diff --git a/regress/man/TP/vert.in b/regress/man/TP/vert.in
new file mode 100644
index 00000000..086976df
--- /dev/null
+++ b/regress/man/TP/vert.in
@@ -0,0 +1,17 @@
+.\" $OpenBSD: vert.in,v 1.1 2020/02/27 01:25:58 schwarze Exp $
+.TH TP-VERT 1 "February 19, 2020"
+.SH NAME
+TP-vert \- vertical spacing before tagged paragraphs
+BEGINTEST
+.SH DESCRIPTION
+.PD 2v
+.TP
+tag
+text
+.TP
+tag
+text
+.PP
+ENDTEST
+.br
+end of file
diff --git a/regress/man/TP/vert.out_ascii b/regress/man/TP/vert.out_ascii
new file mode 100644
index 00000000..32b26ca9
--- /dev/null
+++ b/regress/man/TP/vert.out_ascii
@@ -0,0 +1,20 @@
+TP-VERT(1)                  General Commands Manual                 TP-VERT(1)
+
+
+
+NNAAMMEE
+       TP-vert - vertical spacing before tagged paragraphs BEGINTEST
+
+DDEESSCCRRIIPPTTIIOONN
+       tag    text
+
+
+       tag    text
+
+
+       ENDTEST
+       end of file
+
+
+
+OpenBSD                        February 19, 2020                    TP-VERT(1)
diff --git a/regress/man/TP/vert.out_html b/regress/man/TP/vert.out_html
new file mode 100644
index 00000000..7301819f
--- /dev/null
+++ b/regress/man/TP/vert.out_html
@@ -0,0 +1,9 @@
+</section>
+<section class="Sh">
+<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
+<dl class="Bl-tag">
+  <dt>tag</dt>
+  <dd>text</dd>
+  <dt>tag</dt>
+  <dd>text</dd>
+</dl>