Re: Bug#337787: .MTO produces email addresses with stray whitespace

[Colin Watson]

(For bug-groff, the original bug report is here:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=337787)

On Sun, Nov 06, 2005 at 02:36:49PM +0000, Martin Michlmayr wrote:
> Using .MTO for email addresses (as seen in the groff man page) results
> in a stray space put before the closing bracket.
> 
> Example:
> 
> 1284:address@hidden: ~] cat t
> .
> .mso www.tmac
> .
> 
> .MTO address@hidden "Martin Michlmayr"
> 
> 1285:address@hidden: ~] man -l t -P cat | head -3
> Reformatting t, please wait...
> 
> Martin Michlmayr address@hidden

That isn't actually whitespace - the angle bracket characters there
(U+2329 and U+232A) are classified as double-width, so you see roughly
an extra half-space either side.

groff's devutf8 was changed a little while back to generate the
single-width characters U+27E8 and U+27E9 instead:

2003-02-24  Werner LEMBERG  <address@hidden>

[...]
        Map `la' and `ra' to U+27E8 and U+27E9.  These two characters have
        normal width, while the previously used characters (U+2329 and
        U+232A) are classified as wide due to canonical equivalence with the
        CJK punctuation characters U+3008 and U+3009.

        * font/devutf8/R.proto: Updated.
        * src/roff/troff/uniglyph.cc, src/roff/troff/glyphuni.cc: Ditto.

However, devhtml wasn't changed, and still maps \[la] to U+2329 and
\[ra] to U+232A.  Werner, was this a mistake or am I just missing a
reason?

> Also, these brackets are special UTF-8 chars and cannot be simply
> C&Ped into a mail program.

I never understood why www.tmac's defaults were this way.  It just does
not make sense to delimit Internet e-mail addresses using characters
other than those specified by RFC822 and successors to enclose mailbox
addresses.  Why don't we just use < and > here rather than \[la] and
\[ra]?

The same style is used for .URL and .IMG too, so the choice would be
between changing all of them and separating out the styles.  To be
honest I don't think it would be all that bad to just use ASCII <> for
everything; they don't seem particularly less typographically sound than
the Unicode MATHEMATICAL LEFT ANGLE BRACKET and MATHEMATICAL RIGHT ANGLE
BRACKET characters we're using right now.

(I know that this can be changed with .LINKSTYLE, but it would be better
to have sensible defaults.)

Thanks,

-- 
Colin Watson                                       address@hidden