Re: grohtml: confused about constant-width font handling

"G. Branden Robinson" <[email protected]> Tue, 20 Jan 2026 11:27:06 -0600

Newsgroups	gmane.comp.printing.groff.general
Message-ID	<20260120172706.sx37op4wycpainay@illithid>

Hi Colin,

At 2026-01-20T15:20:55+0000, Colin Watson wrote:
> I'm working through some Debian packages whose tests fail with groff
> 1.24.0.rc1.  One of those is xlbiff, where there was a previous
> attempt to improve the handling of constant-width font selection in
> https://github.com/edsantiago/xlbiff/commit/e0987fbbcd2304b389f70bbedb9ab9201c8bd7f1.
> 
> My current plan is to add the following preamble to the affected
> pages:
> 
>   .ie n .ds CR R
>   .el .ds CR CR

The name "CR" is a groffism, but you probably knew that.  (There are no
portable font names in AT&T troff.)  Just making full disclosure.
> 
> ... and then just use `.ft \*(CR` in each of the places where it
> currently has a conditional.  This seems to work fine for utf8, ps,
> and pdf output.

Yup.  Go for it!

> However, when I tested with -Thtml I found that the expected <pre> or <tt>
> tag was missing.  I don't exactly remember how this works, so I poked around
> in src/devices/grohtml/post-html.cpp and found this:
> 
>   void html_printer::start_font (const char *fontname)
>   {
>     assert(fontname != 0 /* nullptr */);
>     [...]
>     } else if (strcmp(fontname, "CR") == 0) {
>       if ((! fill_on)
>           && is_courier_until_eol()
>           && is_line_start(! fill_on)) {
>         current_paragraph->do_pre();
>       }
>       current_paragraph->do_tt();
>     [...]
>     }
>   }
> 
> So that should work, right?  CR is meant to turn into a <pre> or <tt>
> tag depending on the context.  But even with current git master, it
> doesn't seem to:
> 
>   $ cat t.1
>   .TH T 1
>   .SH NAME
>   t \- a test
>   .SH DESCRIPTION
>   .ft CR
>   constant-width text
>   $ ./test-groff -ww -man -Thtml t.1
>   [...]
>   <p style="margin-left:6%; margin-top: 1em">constant-width
>   text</p>
> 
> So there's no warning, but also no actual constant-width output.  Am I
> holding it wrong somehow, or is this broken?

Nope.  It's broken.

I don't see a Savannah ticket for this, but I recall complaining
exasperatedly to this list[1] (or maybe to some Savannah ticket that
_does_ exist) about grohtml's crude technique of employing <pre>
sometimes, when that implies too much (more than a change of typeface),
and failing to switch the typeface at all at other times.

Regards,
Branden

[1] I'd search, but Web connections to lists.gnu.org/archive are once
    again timing out for me.

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