gtbl leader bug ?

[Mark Kot]

I just tried the input source

.TS
center ;
cp-3    cp-3    .
=
.sp 5p
TERM    MEANING
.sp 5p
_
.sp 5p
.T&
lw(1.0i)        l       .
Pica \a Twelve points.  Six Picas to an inch.
Rule \a Jargon for horizonal or vertical rule.
Leader \a       Your're reading about them now.
Leading \a      Vertical spacing between lines of text.
.sp 5p
_
.TE

as suggested on page 116 of

   McGilton, H. and McNabb, M.  1990.  Typesetting Tables on the
      Unix System.  Trilithon Press.

My copy of dwb tbl and troff and the tbl and troff that are
native to my machine (Solaris 2.7) both generate the output
illustrated in this book.  However groff -t  (version 1.17.2)
generates a faulty table.  In particular, the second column
of data is not left-aligned.  The problem goes away when the
\a leader sequences are removed.

        Is this a previously reported bug ?