anomalous -ms diagnostic for initial keep

[Doug McIlroy]

In groff 1.20.1, -ms input that begins
.KF
.LP
draws a special diagnostic that says .LP "must be in top-level
environment, not `k', when first page is started"
But ...  if you put a blank line before .KF,

.KF
.LP
.KE
you get a nonsense diagnostic: "KE without KS or KF".

Both diagnostics strike me as wrong. Why shouldn't a
document begin with a keep?

I met the problem in real life, while debugging pic
input.  The picture, which was ultimately to be 
included in a bigger document via .PS <file, was
accompanied by a caption--thus it was bracketed
by .KF/.KE.

Doug McIlroy