Re: [Lilypond-auto] Issue 2575 in lilypond: Ambitus is incorrect in the case of semitone staves

[lilypond]

Comment #1 on issue 2575 by address@hidden: Ambitus is incorrect in the case  
of semitone staves
http://code.google.com/p/lilypond/issues/detail?id=2575

I don't expect LilyPond to guess ahead, so I would only expect reasonably  
correct results when using

\new Staff \with
  { \consists Ambitus_engraver
    middleCPosition = #1 }
{
        c' c''
}

\new Staff \with
  { \consists Ambitus_engraver
    staffLineLayoutFunction = #ly:pitch-semitones }
{
        c' c''
}

However, this "time-invariant" way of establishing the settings does not  
actually produce a result different from the original example, and so  
definitely a fix seems required.