[groff] 08/10: tmac/an-old.tmac: Add fallback for lq, rq strings.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit cbbee845b98bbb81fcf3eaf0bfe10dc6d85cb2b1
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Oct 17 00:04:34 2020 +1100

    tmac/an-old.tmac: Add fallback for lq, rq strings.
    
    Define \*(lq and \*(rq as '"' if the output device has no \(lq or \(rq
    special character escapes defined (respectively).
    
    This is a bit belt-and-suspenders for groff since our output devices all
    guarantee availability of these glyphs, but if this macro file gets used
    with other implementations (and if they support the 'c' conditional), it
    should prevent the strings from producing empty output.
    
    Man page writers should simply use \(lq and \(rq unless they are aiming
    for pathological levels of portability (e.g., composing man pages today
    for consumption on simulators of 1980s Unix systems).
---
 tmac/an-old.tmac | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tmac/an-old.tmac b/tmac/an-old.tmac
index e21c65b..f169f54 100644
--- a/tmac/an-old.tmac
+++ b/tmac/an-old.tmac
@@ -623,8 +623,10 @@
 .ds S \s'\\n(PSu'\"
 .ie c\[tm] .ds Tm \(tm\"
 .el        .ds Tm (TM)\"
-.ds lq \(lq\"
-.ds rq \(rq\"
+.ie c\[lq] .ds lq \(lq\"
+.el        .ds lq ""\"
+.ie c\[rq] .ds rq \(rq\"
+.el        .ds rq ""\"
 .
 .\" For UTF-8, map some characters conservatively for the sake
 .\" of easy cut and paste.