weird \s

[Doug McIlroy]

Does anyone else see the following behavior?
Version 1.22.4 handles \s correctly up to \s39, but
truncates a size of 40 or greater to its first
digit. Here are two screen shots, with ^D edited in
to show where input ends and output begins.

groff | tail -5
\s39 hello
^D
%%EndPageSetup
/F0 39/Times-Roman@0 SF(hello)81.75 12 Q 0 Cg EP
%%Trailer
end
%%EOF

groff |tail -5
\s40 hello
^D
%%EndPageSetup
/F0 4/Times-Roman@0 SF 1(0h)72 12 S(ello)-1 E 0 Cg EP
%%Trailer
end
%%EOF

The second example takes "0" as text, not part of the number 40.
I met the behavior with \s48. It continues at least 
through \s50.

Doug