RE: [RFC/NOPATCHv3 4/4] doc: remove GNU_ROFF option

From: Felipe Contreras <felipe.contreras@gmail.com>
To: Felipe Contreras <felipe.contreras@gmail.com>, git@vger.kernel.org
Cc: "brian m . carlson" <sandals@crustytoothpaste.net>,
	"Martin Ågren" <martin.agren@gmail.com>,
	"Bagas Sanjaya" <bagasdotme@gmail.com>,
	"Jeff King" <peff@peff.net>, "Junio C Hamano" <gitster@pobox.com>
Subject: RE: [RFC/NOPATCHv3 4/4] doc: remove GNU_ROFF option
Date: Fri, 18 Jun 2021 16:34:56 -0500	[thread overview]
Message-ID: <60cd118096008_c0ff92085b@natae.notmuch> (raw)
In-Reply-To: <20210618203057.790320-5-felipe.contreras@gmail.com>

Felipe Contreras wrote:
> From: "brian m. carlson" <sandals@crustytoothpaste.net>
> 
> By default, groff converts apostrophes in troff source to Unicode
> apostrophes.

This has nothing to do with the actual problem. As stated in groff(7)
the apostrophe ' is converted to single closing quote \(cq.

Our problem was with acute accent \(aa, not \(cq.

And it was due to docbook doing \' where it shouldn't, not groff.

> This is helpful and desirable when being used as a
> typesetter, since it makes the output much cleaner and more readable,
> but it is a problem in manual pages, since apostrophes are often used
> around shell commands and these should remain in their ASCII form for
> compatibility with the shell.

manpages should use \(aq if they want an apostrophe quote '.

> Fortunately, the DocBook stylesheets contain a workaround for this case:
> they detect the special .g number register, which is set only when using
> groff, and they define a special macro for apostrophes based on whether
> or not it is set and use that macro to write out the proper character.

Once again nothing to do with the issue.

The only way in troff source to specify an apostrophe quote is using
\(aq, but that only works in groff. Since there's no better way to
describe the same for other troff programs ' should be used for
portability.

Doing this:

  .ie \n(.g .ds Aq \(aq
  .el .ds Aq '

is not a workaround: it's a proper implementation of a generic apostrophee
quote that works correctly everywhere.

> As a result, the DocBook stylesheets handle all cases correctly
> automatically, whether the user is using groff or not, unlike our
> GNU_ROFF code.

Yes, but you are not mentioning where it was broken, and when it was
fixed.

> Additionally, this functionality was implemented in 2010.  Since nobody
> is shipping a mainstream Linux distribution with security support that
> old anymore, we can just safely assume that the user has upgraded their
> system in the past decade and remove the GNU_ROFF option and its
> corresponding stylesheet altogether.

Correct, but my version [1] goes into much more detail with less text,
it's actually acurate, and points exactly where docbook got broken,
where it was fixed, and how other projects worked around the issue.

Cheers.

[1] https://lore.kernel.org/git/20210608090026.1737348-2-felipe.contreras@gmail.com/

-- 
Felipe Contreras