".It Xo" ... generates improper output on groff 1.18.1

[Kazuo Horikawa]

Hi,

Recently, using groff 1.18.1, I realized that sequences like below
produce improper output.

.It Xo
.Em start
and
.Em size
.Xc
fields provide the start address
and size of a slice in sectors.

Sequence above taken from src/sbin/fdisk/fdisk.8 rev 1.34 is formated
as follows:

     andrsize'                      fields provide the start address and size
                           of a slice in sectors.

I could see "warning: missing closing delimiter" on stderr, if -ww is
specified.

Is this fixed by recent groff 1.19, or still existing problem?

Thanks,
--
Kazuo Horikawa