[groff] 17/36: [mm]: Restore support for argumentless `AU`.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 79fb2fd0424063fbf36fd1143346f4154d439151
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Jan 16 12:23:50 2023 -0600

    [mm]: Restore support for argumentless `AU`.
    
    * contrib/mm/m.tmac (AU): Partially revert commit 4fd984adc9,
      2021-07-17.  `AU` can be called for the sole purpose of "closing" a
      document title "opened" with `TL`.
    * contrib/mm/groff_mm.7.man (Macros) <AU>: Update description.
---
 contrib/mm/ChangeLog      | 18 +++++++++---------
 contrib/mm/groff_mm.7.man | 21 +++++++++++++--------
 contrib/mm/m.tmac         | 28 +++++++++++++---------------
 3 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/contrib/mm/ChangeLog b/contrib/mm/ChangeLog
index a9c933f53..45a7fc57b 100644
--- a/contrib/mm/ChangeLog
+++ b/contrib/mm/ChangeLog
@@ -1,3 +1,10 @@
+2023-01-16  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * m.tmac (AU): Partially revert commit 4fd984adc9, 2021-07-17.
+       `AU` can be called for the sole purpose of "closing" a document
+       title "opened" with `TL`.
+       * groff_mm.7.man (Macros) <AU>: Update description.
+
 2023-01-16  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * m.tmac (TM): Warn if called without arguments.
@@ -54,10 +61,6 @@
        * tests/MT-1-reports-all-TM-numbers.sh: Do it.
        * mm.am (mm_TESTS): Run test.
 
-2023-01-03  G. Branden Robinson <g.branden.robinson@gmail.com>
-
-       * groff_mm.7.man (AU): Fix error; an argument is mandatory.
-
 2022-12-17  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * m.tmac (let*mt-sign): Check strings populated by optional
@@ -250,11 +253,8 @@
 
        Refactor author title handling.
 
-       * m.tmac (AU): Emit error diagnostic and skip remainder of macro
-       definition if called without arguments; this will keep people
-       familiar with the ms package from getting incorrect and
-       surprising output.  Initialize `cov*at!` array element to zero
-       for current author number (`AT` already updates it).
+       * m.tmac (AU): Initialize `cov*at!` array element to zero for
+       current author number (`AT` already updates it).
 
        * mm/ms.cov (cov@print-authors): Enforce requirement documented
        in groff_mm(7) that .AU is mandatory if .COVER is used.  Emit
diff --git a/contrib/mm/groff_mm.7.man b/contrib/mm/groff_mm.7.man
index eb2c454fd..37f7b9540 100644
--- a/contrib/mm/groff_mm.7.man
+++ b/contrib/mm/groff_mm.7.man
@@ -724,7 +724,8 @@ cover sheet style.
 .
 .
 .TP
-.BI AU\~ name\~\c
+.BR AU \~\c
+.RI [ name\~\c
 .RI [ initials\~\c
 .RI [ loc\~\c
 .RI [ dept\~\c
@@ -732,15 +733,15 @@ cover sheet style.
 .RI [ room\~\c
 .RI [ arg1\~\c
 .RI [ arg2\~\c
-.RI [ arg3 ]]]]]]]]
-Author information.
-.
-Specifies the author of the memo or paper,
-and is printed on the cover sheet and in other similar places.
+.RI [ arg3 ]]]]]]]]]
+Specify author.
 .
 .B AU
-must not appear before
-.BR TL .
+terminates a document title being collected with
+.BR TL ,
+and can be called without arguments for that sole purpose.
+.
+Author information appears on cover sheets and similar places.
 .
 The author information can contain initials,
 location,
@@ -749,6 +750,10 @@ telephone extension,
 room number or name,
 and up to three additional arguments.
 .
+Repeat
+.B AU
+to identify multiple authors.
+.
 .
 .TP
 .BI AV\  \fR[\fPname\  \fR[\fP1\fR]]\fP
diff --git a/contrib/mm/m.tmac b/contrib/mm/m.tmac
index 9c7039885..e1dd8082e 100644
--- a/contrib/mm/m.tmac
+++ b/contrib/mm/m.tmac
@@ -3043,23 +3043,21 @@ in=\\n[.i] fi=\\n[.u] .d=\\n[.d] nl=\\n[nl] pg=\\n[%]
 .ec
 ..
 .\"-------------------
-.\" .AU name [initials [loc [dept [ext [room [arg [arg [arg]]]]]]]]
+.\" .AU [name [initials [loc [dept [ext [room [arg [arg [arg]]]]]]]]]
 .de AU
 .cov@title-end
-.ie !\\n[.$] .@error AU: no arguments
-.el \{\
-.      pg@disable-top-trap
-.      nr cov*au +1
-.      nr cov*at!\\n[cov*au] 0 \" no titles for this author yet
-.      nr cov*i 0 1
-.      ds cov*au!\\n[cov*au]!1
-.      while \\n[.$]>=\\n+[cov*i] \{\
-.              ds cov*au!\\n[cov*au]!\\n[cov*i] "\\$[\\n[cov*i]]
-.      \}
-.      if (\\n[.$]>=3)&(\w@\\$3@) \{\
-.              if d cov*location-\\$3] \{\
-.                      ds cov*au!3!\\n[cov*au] \\*[cov*location-\\$3]
-.              \}
+.if !\\n[.$] .return \" AU is being used only to end a TL.
+.pg@disable-top-trap
+.nr cov*au +1
+.nr cov*at!\\n[cov*au] 0 \" no titles for this author yet
+.nr cov*i 0 1
+.ds cov*au!\\n[cov*au]!1
+.while \\n[.$]>=\\n+[cov*i] \{\
+.      ds cov*au!\\n[cov*au]!\\n[cov*i] "\\$[\\n[cov*i]]
+.\}
+.if (\\n[.$]>=3)&(\w@\\$3@) \{\
+.      if d cov*location-\\$3] \{\
+.              ds cov*au!3!\\n[cov*au] \\*[cov*location-\\$3]
 .      \}
 .\}
 ..