Extend bar line to fit raised staff

[Gerardo Ballabio]

Hello,
I'm using Staff.StaffSymbol.line-positions to raise the staff position
in the middle of a line. When the change is at the end of a measure,
the bar line is aligned with the new staff, leaving the old staff
partially "open", that is, the bar line doesn't extend over all the
height of the old staff -- in the example below, the lowermost space
remains open.
Is there a way to extend the bar line so that it closes both staves?

Thanks
Gerardo

%%%%%
\version "2.24.1"

\relative c'' {
  c1
  \stopStaff
  \override Staff.StaffSymbol.line-positions = #'(-2 0 2 4 6)
  \startStaff
  c1
}
%%%%%