[groff] 28/30: [mdoc]: Add a (helpful?) warning.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit e219991c7c6d1a355199eec3f884dd595de7a663
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Thu Oct 10 10:42:54 2024 -0500

    [mdoc]: Add a (helpful?) warning.
    
    * tmac/doc.tmac (doc-enclose-string): Add warning.  mdoc input like this
    
        .Sq ,
    
      ...is something I see from time to time; it's a conspicuous hazard of
      mdoc's macro system within a macro system.  It leads to an unhelpful
      diagnostic when GNU troff warnings are dialed up.
    
        warning: register 'doc-type0' not defined
    
      Throw document maintainers, if not readers, a bone.
    
    Observed in a shell (from the Sindh?  maybe the Punjab) known as Lokesh.
    
    troff:../loksh/ksh.1:977: warning: register 'doc-type0' not defined
---
 ChangeLog     | 16 ++++++++++++++++
 tmac/doc.tmac |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 8d58062aa..18117793f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2024-10-10  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * tmac/doc.tmac (doc-enclose-string): Add warning.  mdoc input
+       like this
+
+         .Sq ,
+
+       ...is something I see from time to time; it's a conspicuous
+       hazard of mdoc's macro system within a macro system.  It leads
+       to an unhelpful diagnostic when GNU troff warnings are dialed
+       up.
+
+         warning: register 'doc-type0' not defined
+
+       Throw document maintainers, if not readers, a bone.
+
 2024-10-10  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * tmac/an.tmac:
diff --git a/tmac/doc.tmac b/tmac/doc.tmac
index 8a39d0935..c926b6419 100644
--- a/tmac/doc.tmac
+++ b/tmac/doc.tmac
@@ -1724,6 +1724,8 @@
 .    \" resp. suffix
 .    ie (\n[doc-type\n[doc-arg-count]] == 3) \{\
 .      nr doc-reg-des (\n[doc-arg-count] - 1)
+.      if !r doc-type\n[doc-reg-des] \
+.        doc-warn possible missing dummy character '\&' before argument
 .      while (\n[doc-type\n[doc-reg-des]] == 3) \
 .        nr doc-reg-des -1
 .