Possible bug in 2.12.[23]

[Herman Grootaers]

> I'm not top posting.

Greetings all,

I have recently restarted a project of myself, because I do have some free 
time to spare.

So I started to upgrade a number of scores I had already done and I discovered 
the following excerpt which does behave weird. It is in the alto-part of a 
four-voice a-capella choir-piece which in one bar is split. The lyrics however 
are not handled correctly, due to the fact that the alto-part is completely 
gone, but will be taken on in the next bar.

If I reduce  the excerpt to the offending part of the bar I get an error 
indicating that the alto-part is missing, although is printed. strange 

This behaviour is also in version 2.12.2, earlier versions I cannot remember 
if this was already in place.

Yours,
Herman Grootaers
Ps: I am subscribed to the bu-list, i.e. I do receive the mails from the bug-
list.



>> Lilypond-listing <<
\version "2.12.3"
global = { \key g \major
           \time 4/4
         }
ignore = \override NoteColumn #'ignore-collision = ##t
hs = \once \override NoteColumn #'force-hshift = #1.7
sop = \relative c'' { c2 \hs b }
alt = \relative c'' { a2 << { \stemDown \hs \ignore e2 } \\ { a4( gis) } >> }
ten = \relative c'  { e2 d }
bas = \relative c   { e2 <<e, e'>> }
koor = \lyricmode { bla bla }
\score
{ \context ChoirStaff
   << \context Staff = "women"
     << \clef treble
        \set Staff.instrumentName = \markup { \center-column { Soprano Alto } }
        \context Voice = "soprano" { \voiceOne << \global \sop >> }
        \context Voice = "alto" { \voiceTwo << \global \alt >> }
        \context Lyrics = alto { s1 }
     >>
     \context Staff = "men"
     << \clef bass
        \set Staff.instrumentName = \markup { \center-column { Tenor Bas } }
        \context Voice = "tenor" { \voiceOne << \global \ten >> }
        \context Voice = "bass" { \voiceTwo << \global \bas >> }
     >>
     \context Lyrics = alto \lyricsto alto \koor
   >>
   \layout { \context { \Staff } }
}