Override staff-space of zero causes a crash

[Phil Holmes]

Experimenting with staff-space, I set the override to zero and get a crash - 
Windows, both with 2.12.3 and 2.13.36

\new Staff \with { \override StaffSymbol #'staff-space = #0.0 }
\relative c' {
c c c c
}


--
Phil Holmes
Bug Squad