Comment #25 on issue 2990 by [email protected]: \RemoveEmptyStaves in StaffGroup context crashes
http://code.google.com/p/lilypond/issues/detail?id=2990
At any rate, the whole exercise is there for building some sort of directed graph. If we can have a sensible description of what is actually supposed to happen here, it should be reasonably easy to come up with a set of operations that preserve the fundamental graph properties without requiring additional checks.
