Represent mdoc(7) .Pp (and .sp, and some SYNOPSIS and .Rs features)

by the <p> HTML element and use the html_fillmode() mechanism
for .Bd -unfilled, just like it was done for man(7) earlier, finally
getting rid both of the horrible <div class="Pp"></div> hack and
of the worst HTML syntax violations caused by nested displays.

Care is needed because in some situations, paragraphs have to remain
open across several subsequent macros, whereas in other situations,
they must get closed together with a block containing them.

Some implementation details include:
* Always close paragraphs before emitting HTML flow content.
* Let html_close_paragraph() also close <pre> for extra safety.
* Drop the old, now unused function print_paragraph().
* Minor adjustments in the top-level man(7) node formatter for symmetry.
* Bugfix: .Ss heads suspend no-fill mode, even though .Ss doesn't end it.
* Bugfix: give up on .Op semantic markup for now, see the comment.

6 files changed, 35 insertions, 10 deletions

diff --git a/regress/mdoc/D1/Makefile b/regress/mdoc/D1/Makefile
index bed27d1b..b94d5727 100644
--- a/regress/mdoc/D1/Makefile
+++ b/regress/mdoc/D1/Makefile
@@ -1,6 +1,7 @@
-# $OpenBSD: Makefile,v 1.2 2015/02/06 02:04:35 schwarze Exp $
+# $OpenBSD: Makefile,v 1.5 2019/01/07 06:51:37 schwarze Exp $
 
 REGRESS_TARGETS	 = spacing
 LINT_TARGETS	 = spacing
+HTML_TARGETS	 = spacing
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/D1/spacing.in b/regress/mdoc/D1/spacing.in
index e7733298..c0f293c4 100644
--- a/regress/mdoc/D1/spacing.in
+++ b/regress/mdoc/D1/spacing.in
@@ -1,13 +1,20 @@
-.\" $OpenBSD: spacing.in,v 1.3 2017/07/04 14:53:24 schwarze Exp $
-.Dd $Mdocdate: July 4 2017 $
+.\" $OpenBSD: spacing.in,v 1.4 2019/01/07 06:51:37 schwarze Exp $
+.Dd $Mdocdate: January 7 2019 $
 .Dt D1-SPACING 1
 .Os
 .Sh NAME
 .Nm D1-spacing
 .Nd spacing in and around one-line displays
 .Sh DESCRIPTION
-preceding text
+BEGINTEST
+.Pp
+preceding
+paragraph
 .D1 spacing  in  and around one-line displays
 empty display:
 .D1
 following text
+.br
+ENDTEST
+.br
+end of file
diff --git a/regress/mdoc/D1/spacing.out_ascii b/regress/mdoc/D1/spacing.out_ascii
index 40945936..c0d1556d 100644
--- a/regress/mdoc/D1/spacing.out_ascii
+++ b/regress/mdoc/D1/spacing.out_ascii
@@ -4,9 +4,13 @@ NNAAMMEE
      DD11--ssppaacciinngg - spacing in and around one-line displays
 
 DDEESSCCRRIIPPTTIIOONN
-     preceding text
+     BEGINTEST
+
+     preceding paragraph
            spacing in and around one-line displays
      empty display:
      following text
+     ENDTEST
+     end of file
 
-OpenBSD                          July 4, 2017                          OpenBSD
+OpenBSD                         January 7, 2019                        OpenBSD
diff --git a/regress/mdoc/D1/spacing.out_html b/regress/mdoc/D1/spacing.out_html
new file mode 100644
index 00000000..b1a1d4da
--- /dev/null
+++ b/regress/mdoc/D1/spacing.out_html
@@ -0,0 +1,8 @@
+BEGINTEST
+<p class="Pp">preceding paragraph</p>
+<div class="Bd Bd-indent">spacing in and around one-line displays</div>
+empty display:
+<div class="Bd Bd-indent"></div>
+following text
+<br/>
+ENDTEST
diff --git a/regress/mdoc/D1/spacing.out_lint b/regress/mdoc/D1/spacing.out_lint
index 5ac4d0c0..0a2790bb 100644
--- a/regress/mdoc/D1/spacing.out_lint
+++ b/regress/mdoc/D1/spacing.out_lint
@@ -1 +1 @@
-mandoc: spacing.in:12:2: WARNING: empty block: D1
+mandoc: spacing.in:15:2: WARNING: empty block: D1
diff --git a/regress/mdoc/D1/spacing.out_markdown b/regress/mdoc/D1/spacing.out_markdown
index eac16dfe..d1f12f63 100644
--- a/regress/mdoc/D1/spacing.out_markdown
+++ b/regress/mdoc/D1/spacing.out_markdown
@@ -6,12 +6,17 @@ D1-SPACING(1) - General Commands Manual
 
 # DESCRIPTION
 
-preceding text
+BEGINTEST
+
+preceding
+paragraph
 
 > spacing in and around one-line displays
 
 empty display:
 
-following text
+following text  
+ENDTEST  
+end of file
 
-OpenBSD - July 4, 2017
+OpenBSD - January 7, 2019