Issue 1745 in lilypond: Strange vertical space above TupletBracket when moving it for the sake of cross-staff beamed tuplets

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Defect Priority-Medium

New issue 1745 by brownian.box: Strange vertical space above TupletBracket  
when moving it for the sake of cross-staff beamed tuplets
http://code.google.com/p/lilypond/issues/detail?id=1745

Reported by David Nalesnik, see here:
http://lists.gnu.org/archive/html/bug-lilypond/2011-07/msg00116.html

Default placement of tuplet bracket (and number) for tuplets with  
cross-staff beams is, probably, wrong, that's why this code (and see images  
below):

% --------------8<-----------------------

\version "2.15.4"

#(define (tuplet-number-to-beam tuplet-number)
  (let* ((tuplet-bracket (ly:grob-object tuplet-number 'bracket))
         (note-column (ly:grob-parent tuplet-number X))
         (stem (ly:grob-object note-column 'stem))
         (beam (ly:grob-object stem 'beam)))

     ;; Move (invisible) TupletBracket to beam, taking number with it
     (ly:grob-set-property! tuplet-bracket 'positions (ly:grob-property  
beam 'positions))))
}


\new PianoStaff <<
  \new Staff = "1" {
    s4
  }
  \new Staff = "2" {
    \relative c {
      \clef bass
      % \override TupletNumber #'after-line-breaking =  
#tuplet-number-to-beam
      \times 2/3 {
        c8
        \change Staff = "1"
        c''
        \change Staff = "2"
        c,,
      }
    }
  }


% --------------8<-----------------------

So, with 2.15.4 there is much more space _above_ tuplet bracket -- and this  
can be an issue. I failed to "debug" it and classify it better. Since it  
involves Scheme code, I doubt it is Critical.


I am not sure whether can it be related to issue 1702.


Attachments:
        test-2.12.3-noworkaround.png  1.4 KB
        test-2.12.3-workaround.png  1.4 KB
        test-2.15.4-noworkaround.png  1.4 KB
        test-2.15.4-workaround.png  1.5 KB