[groff] 34/35: [mm]: Fix warning on .COVER with no .TL.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 59d1fd7a5e284e0b61827fd9d1c3f34c6986745c
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Jul 17 09:55:08 2021 +1000

    [mm]: Fix warning on .COVER with no .TL.
    
    * contrib/mm/mm/ms.cov (cov@print-title): Enforce requirement documented
      in groff_mm(7) that .TL is mandatory if .COVER is used.  Emit
      diagnostic if `cov*title` is not defined, and skip remainder of macro
      definition.
    
    Resolves warning:
    troff: ./EXPERIMENTS/no-title.mm:2: warning: macro 'cov*title' not defined
---
 contrib/mm/ChangeLog |  7 +++++++
 contrib/mm/mm/ms.cov | 27 +++++++++++++++------------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/contrib/mm/ChangeLog b/contrib/mm/ChangeLog
index d59835d..7b6f4b4 100644
--- a/contrib/mm/ChangeLog
+++ b/contrib/mm/ChangeLog
@@ -1,5 +1,12 @@
 2021-07-17  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       * mm/ms.cov (cov@print-title): Enforce requirement documented in
+       groff_mm(7) that .TL is mandatory if .COVER is used.  Emit
+       diagnostic if `cov*title` is not defined, and skip remainder of
+       macro definition.
+
+2021-07-17  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * mm/ms.cov (COVEND): Fix thinko; test for existence of
        `cov*abs-arg` register with `r` conditional operator, not `d`.
 
diff --git a/contrib/mm/mm/ms.cov b/contrib/mm/mm/ms.cov
index 9b53c37..d371b69 100644
--- a/contrib/mm/mm/ms.cov
+++ b/contrib/mm/mm/ms.cov
@@ -25,18 +25,21 @@ http://savannah.gnu.org/bugs/?group=groff.
 .\" Cover sheet. Mostly like ms cover.
 .\"------------
 .de cov@print-title
-.in 0
-.misc@ev-keep cov*ev
-.init@reset
-.ad c
-.hy 0
-.fi
-.B
-.cov*title
-.br
-.ad b
-.R
-.ev
+.ie !d cov*title .@error COVEND: no title (TL) defined
+.el \{
+.      in 0
+.      misc@ev-keep cov*ev
+.      init@reset
+.      ad c
+.      hy 0
+.      fi
+.      B
+.      cov*title
+.      br
+.      ad b
+.      R
+.      ev
+.\}
 ..
 .\"------------
 .de cov@print-authors