Bar Lines Disappear with Staff Line Count Change

[Mark Mathias]

Why do Bar Lines disappear when reducing the Staff Line count? I've tried several alterations to the layout context for score, but don't get the right results.

 

\version "2.15.33"

\relative c'' {

\override Staff . StaffSymbol #'line-count = #1

b4 s r r

b b8 b b b s4

b s s s

}

 

Thanks!

Mark