Unbreakable spaces in AT&T troff were always non-adjustable.
Define a string to use groff's `\~` extension if possible.
groff_man_style(7):
Portability
...
\~ Adjustable non‐breaking space. Use this escape sequence
to prevent a break inside a short phrase or between a
numerical quantity and its corresponding unit(s).
Before starting the motor,
set the output speed to\~1.
There are 1,024\~bytes in 1\~KiB.
CSTR\~#8 documents the B\~language.
\~ is a GNU extension also supported by Heirloom Doctools
troff 050915 (September 2005), mandoc 1.9.14
(2009‐11‐16), neatroff (commit 1c6ab0f6e, 2016‐09‐13),
and Plan 9 from User Space troff (commit 93f8143600,
2022‐08‐12), but not by DWB or Solaris troffs.
Fixes bad rendering in DWB 3.3 troff:
@@ -999 +999 @@
- file. -s|-s~-v may also be followed by arguments -p
+ file. -s|-s -v may also be followed by arguments -p
@@ -1005 +1005 @@
- entries which match both. -s|-s~-v may be followed by one
+ entries which match both. -s|-s -v may be followed by one
Solaris 10 troff _would_ misrender as well, but a different portability
problem keeps some of the foregoing text from rendering at all.
G. Branden Robinson
1922fb687d