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@.

1 files changed, 27 insertions, 0 deletions

diff --git a/regress/mdoc/Rs/transp.out_markdown b/regress/mdoc/Rs/transp.out_markdown
new file mode 100644
index 00000000..a9896335
--- /dev/null
+++ b/regress/mdoc/Rs/transp.out_markdown
@@ -0,0 +1,27 @@
+RS-TRANSPARENT(1) - General Commands Manual
+
+# NAME
+
+**Rs-transparent** - transparent nodes in reference blocks
+
+# SEE ALSO
+
+first after title,
+last,
+*title*.
+
+first,
+middle, and
+last before title,
+*title*.
+
+first after title and transparent,
+middle before transparent, and
+last before transparent,
+*title*.
+
+first after transparent,
+last before transparent and title,
+*title*.
+
+OpenBSD - February 27, 2020