[groff] 22/24: [mdoc]: Support `HF` string.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 78922cf9f39f6ebcd3a80aaab9c3a2931b8b0ad4
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue Dec 27 02:46:19 2022 -0600

    [mdoc]: Support `HF` string.
    
    * tmac/doc.tmac (initialization): Add logic supporting `HF` string just
      as our man(7) implementation does.  If the font name ends with `B` (as
      the default does), set `doc-remap-I-style-in-headings` register and
      extract font family, which can be empty (as is the default).
    * tmac/mdoc/doc-common (Sh, Ss): If `doc-remap-I-style-in-headings`
      register set, perform (and unwind) font remapping of italic to
      bold-italic face.
    * tmac/mdoc/doc-ditroff:
    * tmac/mdoc/doc-nroff: Define `doc-Sh-font` in terms of `HF`.
    
    * tmac/tests/doc_heading-font-remapping-works.sh: Test it.
    * tmac/tmac.am (tmac_TESTS): Run test.
    
    * tmac/groff_mdoc.7.man (Options): Document it.
    * NEWS: Update item.
    
    Fixes last part of <https://savannah.gnu.org/bugs/?63046>.
---
 ChangeLog                                      | 23 +++++++++++
 NEWS                                           |  3 +-
 tmac/doc.tmac                                  | 19 ++++++++-
 tmac/groff_mdoc.7.man                          | 24 +++++++-----
 tmac/mdoc/doc-common                           | 12 ++++++
 tmac/mdoc/doc-ditroff                          |  2 +-
 tmac/mdoc/doc-nroff                            |  2 +-
 tmac/tests/doc_heading-font-remapping-works.sh | 53 ++++++++++++++++++++++++++
 tmac/tmac.am                                   |  1 +
 9 files changed, 126 insertions(+), 13 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 1ed6de1fd..75b3b129b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,26 @@
+2022-12-27  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [mdoc]: Support `HF` string.
+
+       * tmac/doc.tmac (initialization): Add logic supporting `HF`
+       string just as our man(7) implementation does.  If the font name
+       ends with `B` (as the default does), set
+       `doc-remap-I-style-in-headings` register and extract font
+       family, which can be empty (as is the default).
+       * tmac/mdoc/doc-common (Sh, Ss): If
+       `doc-remap-I-style-in-headings` register set, perform (and
+       unwind) font remapping of italic to bold-italic face.
+       * tmac/mdoc/doc-ditroff:
+       * tmac/mdoc/doc-nroff: Define `doc-Sh-font` in terms of `HF`.
+
+       * tmac/tests/doc_heading-font-remapping-works.sh: Test it.
+       * tmac/tmac.am (tmac_TESTS): Run test.
+
+       * tmac/groff_mdoc.7.man (Options): Document it.
+       * NEWS: Update item.
+
+       Fixes last part of <https://savannah.gnu.org/bugs/?63046>.
+
 2022-12-26  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [tmac]: Revise "fallback" character definitions in several
diff --git a/NEWS b/NEWS
index 808223202..72a8674f5 100644
--- a/NEWS
+++ b/NEWS
@@ -321,7 +321,8 @@ o The groff_man(7) man page documenting the groff 
implementation of the
   reader who is not an expert in *roff systems or in writing man pages.
 
 o The doc (mdoc) macro package now honors the `C`, `FT`, `HY`, `IN`,
-  `P`, `SN`, and `X` registers as the an (man) package does.
+  `P`, `SN`, and `X` registers and `HF` string as the an (man) package
+  does.
 
 o The doc (mdoc) macro package now renders man page (sub)section cross
   references cited with the `Sx` macro by quoting them instead of
diff --git a/tmac/doc.tmac b/tmac/doc.tmac
index 587cef1ee..5bfa65e34 100644
--- a/tmac/doc.tmac
+++ b/tmac/doc.tmac
@@ -155,7 +155,24 @@
 .  \}
 .\}
 .
-.\" TODO: Implement HF string.
+.\" (sub)section heading font
+.if !d HF \
+.  ds HF B\"
+.
+.\" If HF is a bold style, use bold italics for italics in headings.
+.ds doc-heading-style \*[HF]\"
+.substring doc-heading-style -1 -1
+.ds doc-heading-family \" empty
+.length doc-HF-length \*[HF]
+.if (\n[doc-HF-length] > 1) \{\
+.  as doc-heading-family \*[HF]\"
+.  substring doc-heading-family 0 -2
+.\}
+.if '\*[doc-heading-style]'B' \
+.  if F \*[doc-heading-family]BI \
+.    nr doc-remap-I-style-in-headings 1
+.rr doc-HF-length
+.rm doc-heading-style
 .
 .\" \n[HY] is recognized for groff_man(7) compatibility, particuarly via
 .\" andoc.tmac and man(1); see \n[doc-hyphen-flags] in doc-common.
diff --git a/tmac/groff_mdoc.7.man b/tmac/groff_mdoc.7.man
index 2f525fe0c..cad71cb0f 100644
--- a/tmac/groff_mdoc.7.man
+++ b/tmac/groff_mdoc.7.man
@@ -5052,6 +5052,21 @@ The default is \-0.5i.
 .
 .
 .Pp
+The
+.Ql HF
+string sets
+the font used for section and subsection headings;
+the default is
+.Ql B
+(bold style of the default family).
+.
+Any valid argument to
+.Xr groff 7 's
+.Ql ft
+request may be used.
+.
+.
+.Pp
 Normally,
 automatic hyphenation is enabled using a mode appropriate to the
 .Xr groff
@@ -5135,15 +5150,6 @@ request in
 .Xr groff @MAN7EXT@ ) .
 .
 .
-.Pp
-The
-.Ql HF
-string
-is reserved for potential future compatibility with
-.Xr groff_man @MAN7EXT@
-page rendering options.
-.
-.
 .br
 .ne 4v
 .Sh Files
diff --git a/tmac/mdoc/doc-common b/tmac/mdoc/doc-common
index a00a96943..e059c491e 100644
--- a/tmac/mdoc/doc-common
+++ b/tmac/mdoc/doc-common
@@ -1382,6 +1382,9 @@
 .  el \
 .    nr doc-in-name-section 0
 .
+.  if \n[doc-remap-I-style-in-headings] \
+.    ftr I \*[doc-heading-family]BI
+.
 .  ie \n[doc-arg-count] \{\
 .    \" we only allow 'Sh' within 'Sh'; it will change the font back to
 .    \" 'doc-Sh-font'
@@ -1485,6 +1488,9 @@
 .    doc-check-depth
 .  \}
 .
+.  if \n[doc-remap-I-style-in-headings] \
+.    ftr I I
+.
 .  \" Don't let doc-print-recursive force caps on anything else.
 .  nr doc-do-capitalize 0
 ..
@@ -1505,6 +1511,9 @@
 .
 .eo
 .de Ss
+.  if \n[doc-remap-I-style-in-headings] \
+.    ftr I \*[doc-heading-family]BI
+.
 .  ie \n[doc-arg-count] \{\
 .    \" we only allow 'Ss' within 'Ss'; it will change the font back to
 .    \" 'doc-Sh-font'
@@ -1562,6 +1571,9 @@
 .
 .    doc-check-depth
 .  \}
+.
+.  if \n[doc-remap-I-style-in-headings] \
+.    ftr I I
 ..
 .ec
 .
diff --git a/tmac/mdoc/doc-ditroff b/tmac/mdoc/doc-ditroff
index a0347256c..96cb2f725 100644
--- a/tmac/mdoc/doc-ditroff
+++ b/tmac/mdoc/doc-ditroff
@@ -71,7 +71,7 @@
 .ds doc-Nm-font \f[CB]
 .ds doc-No-font \f[R]
 .ds doc-Pa-font \f[I]
-.ds doc-Sh-font \f[B]
+.ds doc-Sh-font \f[\*[HF]]\"
 .ds doc-Sy-font \f[B]
 .ds doc-Tn-font \f[R]
 .ds doc-Va-font \f[I]
diff --git a/tmac/mdoc/doc-nroff b/tmac/mdoc/doc-nroff
index a23c57b3d..5167af3ea 100644
--- a/tmac/mdoc/doc-nroff
+++ b/tmac/mdoc/doc-nroff
@@ -63,7 +63,7 @@
 .ds doc-Nm-font \f[B]
 .ds doc-No-font \f[R]
 .ds doc-Pa-font \f[I]
-.ds doc-Sh-font \f[B]
+.ds doc-Sh-font \f[\*[HF]]\"
 .ds doc-Sy-font \f[B]
 .ds doc-Tn-font \f[R]
 .ds doc-Va-font \f[I]
diff --git a/tmac/tests/doc_heading-font-remapping-works.sh 
b/tmac/tests/doc_heading-font-remapping-works.sh
new file mode 100755
index 000000000..4fdd95acf
--- /dev/null
+++ b/tmac/tests/doc_heading-font-remapping-works.sh
@@ -0,0 +1,53 @@
+#!/bin/sh
+#
+# Copyright (C) 2022 Free Software Foundation, Inc.
+#
+# This file is part of groff.
+#
+# groff is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# groff is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+groff="${abs_top_builddir:-.}/test-groff"
+
+fail=
+
+wail () {
+    echo ...FAILED >&2
+    fail=yes
+}
+
+# Ensure that italics in a section heading get remapped to bold italics
+# (if the heading font is bold).
+
+input='.Dd 2022-12-26
+.Dt foo 1
+.Os "groff test suite"
+.Sh Name
+.Nm foo
+.Nd frobnicate a bar
+.Sh Hacking Xr groff
+Have fun!'
+
+output=$(printf "%s\n" "$input" | "$groff" -mdoc -Tascii -Z)
+echo "$output"
+
+echo "$output" | sed -n '/tHacking/{n
+/x font 4 BI/{n
+/f4/{n
+/h/{n
+/tgroff/{n
+/n/{n
+/f1/p}}}}}}' | grep -Fqx f1
+
+# vim:set ai et sw=4 ts=4 tw=72:
diff --git a/tmac/tmac.am b/tmac/tmac.am
index 51b9de289..82cbb8bbe 100644
--- a/tmac/tmac.am
+++ b/tmac/tmac.am
@@ -201,6 +201,7 @@ tmac_TESTS = \
   tmac/tests/doc_X-register-works.sh \
   tmac/tests/doc_accept-mixed-case-section-headings.sh \
   tmac/tests/doc_do-not-loop-infinitely-when-shortening-headers.sh \
+  tmac/tests/doc_heading-font-remapping-works.sh \
   tmac/tests/doc_indents-correctly.sh \
   tmac/tests/doc_output-footer-when-continuously-rendering.sh \
   tmac/tests/doc_smoke-test.sh \