bug#23647: 25.1.50; In man pages, links on hyphenated words don't work

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: 23647@debbugs.gnu.org
> Date: Mon, 30 May 2016 15:55:47 +0200
> 
> > I'm not enough of a roff expert to tell, but how about asking on the
> > Groff list?
> 
> I did that and got this feedback from Steffen Nurpmeso:
> 
> > I have been convinced that soft hyphen is a control character and
> > not something visual, it should be used as a «break-indicator»
> > rather than as a hyphenation character, interpretation of which is
> > left as an excercise for the processing software.  I have no idea
> > still but would guess groff uses "hyphen minus" U+002D or hyphen
> > U+2010 if Unicode is possible.
> 
> In a followup to another response he added:
> 
> > For display purposes however i think U+00AD can't be used
> > directly, but will be replaced by the renderer to either nothing,
> > if no wrap is to be applied at the character position, or
> > something appropriate, like ASCII hyphen-minus or some extended
> > Unicode "Pd" letter, of which there are some (e.g., U+058A
> > ARMENIAN HYPHEN, U+1400 CANADIAN SYLLABICS HYPHEN, and more).
> 
> And he also made this suggestion:
> 
> > Eli Zaretskii is so active on the
> > Unicode list, why don't you use the Pd character class for
> > detecting «hyphen»?  I guess this should cover all such things
> > already as of today, thanks to Werner Lemberg?!
> 
> So how should we proceed from here?  We could add U+2010 to the regexp
> in my patch, which would then be this: "[-‐­]" (hyphen-minus (ASCII 45),
> hyphen (U+2010), soft hyphen (U+00AD) -- it seems harmless to retain the
> latter, given that man.el already uses it elsewhere), but if these are
> all included in the Unicode Pd character class along with other possible
> hyphen characters, maybe a different approach is required.  I know
> nothing about the Pd character class and how to detect it with Elisp; I
> also don't know if doing that would lead to further changes in man.el,
> making this a larger undertaking.  What do you suggest?

I'd go with just those 3, I think the others will not be produced by
Groff.

Thanks.