Re: Glyphs sometimes don't render with unicode hexcodes and pdf/ps/html devices

On 2026-03-08 Dave Kemper wrote:

> On Sun, Mar 8, 2026 at 1:54 PM Deri via discussion of the GNU roff
> typesetting system and related software <[email protected]> wrote:
>> I did open a bug about this sometime ago.
>
> This appears to be http://savannah.gnu.org/bugs/?65716 , which is in
> the Need Info state for info that no one in the groff arena has
> knowledge of.  If you can shed any light here, Morten, that could help
> bring about a resolution.

Not sure how helpful I can be; I am not at all well versed in the intrinsics
of groff font handling. I am basically just an end user, but I seem to
gather that for the aliases such as "parenlefttp" to work, they must be at
the beginning of the entries in the font files, as e.g. in

  parenlefttp     384,926,293,52  3       230     parenlefttp     -- F8EB
  
which means that only these "core aliases", if I may call them that, will
work. In font files, externally installed with e.g. Peter's or Deri's
scripts, the aliases do not work. But for my own needs, the solution was
easy: I just use the first field in the entries in the font files. Sometimes
this is an alias, sometimes it is a hex code. Either way, it should work.
Previously, I only used the hex codes and this is why I ran into this
problem. One could check the font files for undefined hex codes like this
(for the "U-S" file);

for hex in $(grep -Eo "[0-9a-fA-F]{4,6}" U-S)
do
  echo "\\\f[U-S]\[u$hex]\f" | groff -Tpdf 2> >(grep -v "input code 12" >&2) | pdftotext - -
done

(It kept complaining about a "character with input code 12 not defined")

Regards,
Morten