Issue 879

[Phil Holmes]

Is about knees, crossing staves, and the RemoveEmptyStaff  command.  It took 
me to engraver-init.ly where I found:

RemoveEmptyStaves = \with {
 \remove "Axis_group_engraver"
 \remove "Hara_kiri_engraver"
 \consists "Hara_kiri_engraver"
 \override Beam #'auto-knee-gap = #'()
 \override VerticalAxisGroup #'remove-empty = ##t
}

I know I don't properly understand this stuff still, but doesn't the 
\consists re-instate the previously removed engraver on the line above?

--
Phil Holmes
Bug Squad