bin/58074: .Lk mishandles missing anchor-text

[uwe%stderr.spb.ru@localhost]

>Number:         58074
>Category:       bin
>Synopsis:       .Lk mishandles missing anchor-text
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 24 15:20:00 +0000 2024
>Originator:     Valery Ushakov
>Release:        NetBSD 10
>Organization:
>Environment:
NetBSD snips 10.0_RC3 NetBSD 10.0_RC3 (GENERIC) #0: Wed Jan 17 21:22:02 MSK 2024  uwe@majava:/home/uwe/work/netbsd/cvs/src-release-10/sys/arch/macppc/compile/GENERIC macppc

>Description:
From source code inspection .Lk with a missing anchor-text but with
the trailing punctuation is intended to do the right thing, but
doesn't.  E.g. in distrib/notes/common/main

revision 1.574
date: 2024-03-24 16:18:02 +0300;  author: martin;  state: Exp;  lines: +3 -4;  commitid: caZuafzIoIV5Mp3F;
Use single-arg "Lk" macro for a link so we can get reasonable results
both in .more and .html output (still a bit odd, but better than before IMHO).

had to drop the trainling dot from what should have been

  .Lk https://www.NetBSD.org/ .

b/c the above is currently misformatted as:

  For more information please visit .: https://www.NetBSD.org/

instead of

  For more information please visit https://www.NetBSD.org/.

>How-To-Repeat:
Use

  .Lk http://some/url .

in a mdoc document.

>Fix:
From a quick source code inspection Lk seems to have the intention to
handle the above properly.  The Lk macro is defined to

  .de Lk
  .  ds doc-str-Lk Sy \$@
  .
  .  ie (\n[.$] > 1) \{\
  .    doc-get-arg-type \$2
  .    ie (\n[doc-arg-type] < 3) \{\
  .      Em \)\$2:
  .      ds doc-str-Lk Sy "\$1"
  .      doc-get-width "\$1"
  .      shift 2
  .      if \n[.$] \
  .        as doc-str-Lk " \$@
  .    \}
  .    el \
  .      doc-get-width "\$1"
  .  \}
  .  el \
  .    doc-get-width "\$1"

i.e. if the second argument is a punctuation (doc-arg-type is 3 or
more), it is not treated as an anchor-text (cf. the top-level else for
the case of just one argument).

The bug seems to be that while the doc-get-arg-type is documented to
expect the width of the argument in `doc-width', Lk doesn't do that
(cf. other uses of these macros elsewhere in doc.tmac).  The fix is
probably just:

--- doc.tmac.~1.2.~	2016-01-13 22:01:59.000000000 +0300
+++ doc.tmac	2024-03-24 18:12:18.401745081 +0300
@@ -6416,6 +6416,7 @@
 .  ds doc-str-Lk Sy \$@
 .
 .  ie (\n[.$] > 1) \{\
+.    doc-get-width \$2
 .    doc-get-arg-type \$2
 .    ie (\n[doc-arg-type] < 3) \{\
 .      Em \)\$2:

which seems to do the right thing for the release notes with

  .Lk https://www.NetBSD.org/ .

in distrib/notes/common/main, getting

  <a href="https://www.NetBSD.org/";>https://www.NetBSD.org/</a>.

and

    https://www.NetBSD.org/.

(with the url in bold and dot not in bold).