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, 42 insertions, 0 deletions

diff --git a/regress/mdoc/Fl/spacing.out_markdown b/regress/mdoc/Fl/spacing.out_markdown
new file mode 100644
index 00000000..a46a44e3
--- /dev/null
+++ b/regress/mdoc/Fl/spacing.out_markdown
@@ -0,0 +1,42 @@
+FL-SPACING(1) - General Commands Manual
+
+# NAME
+
+**Fl-spacing** - horizontal spacing after flag macros
+
+# DESCRIPTION
+
+with argument:
+**-a**
+
+no next node:
+**-** suffix
+
+transparent next node only:
+**-**
+suffix
+
+following text:
+**-**
+text
+
+text after transparent node on the same line:
+**-**
+text
+
+following macro on the same line:
+**-**‌*word*
+
+following macro on the next line:
+**-**
+*word*
+
+following macro on the next line after transparent node on the same line:
+**-**
+*word*
+
+following macro after transparent node on the next line:
+**-**
+*word*
+
+OpenBSD - February 27, 2020