Issue 1208 in lilypond: "minor regression": Some combination of 'staff-affinity for two Lyrics may cause unwanted vertical space

[lilypond]

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

New issue 1208 by brownian.box: "minor regression": Some combination  
of 'staff-affinity for two Lyrics may cause unwanted vertical space
http://code.google.com/p/lilypond/issues/detail?id=1208

This appeared in 2.13.29.

Different combinations for two Lyrics (see below) give in result:
 - UP, UP --- ok
 - UP, CENTER --- ok
 - UP, DOWN (default, commented out or set explicitly) -- ok
 - CENTER, CENTER --- *bad*
 - CENTER, DOWN --- *bad*

(Those "bad" reflect my expectancy. Among other things i mean that failed  
to arrange this with spacing settings. Sorry.)

I've attached some examples.

This may also be related to issue 1161.

%-----------------------8<----------------------------
\version "2.13.29"

alto = \relative g' {
  g4 g g g
  R1
  g4 g g g
}


tenor = \relative f {
  R1
  f4 f f f
  R1
}


altolyrics = \lyricmode {
  u u u u
  u u u u
}

tenlyrics = \lyricmode {
  l l l l
}

%
\score {
  \context ChoirStaff <<
    \new Staff = "upperstaff" <<
      \key bes \major
      \new Voice = "alto" { \voiceTwo \alto }
      \context Lyrics = "altolyrics" \with {
        \override VerticalAxisGroup #'staff-affinity = #CENTER
      } \lyricsto "alto" \altolyrics
    >>
    %
    \new Staff = "tenstaff" <<
      \clef "bass"
      \key bes \major
      \new Voice = "tenor" { \voiceOne \tenor }
      \context Lyrics = "tenlyrics" \with {
        alignAboveContext = "tenstaff"
        \override VerticalAxisGroup #'staff-affinity = #CENTER
      } \lyricsto "tenor" \tenlyrics
    >>
  >>
}
%-----------------------8<----------------------------

Attachments:
        test--2.13.29--UP-UP.png  2.2 KB
        test--2.13.29--CENTER-CENTER.png  2.3 KB
        test--2.13.28--CENTER-CENTER.png  2.2 KB