Re:Weird behaviour of new NullVoice feature

[Yann]

>> Is it a bug ?
>
> I think so and I've created
> https://code.google.com/p/lilypond/issues/detail?id=3825&colspec=ID%20Type%20Status%20Stars%20Owner%20Patch%20Needs%20Summary
> for this
>
> thanks for reporting it!
> Eluze
>

Thanks for creating the issue on the tracker.
I was playing again with NullVoice, and I noticed some unpredictable
behaviour with the following example :

\version "2.18.0"
<<
  \new Staff <<
    \new Voice = "melodie" \relative c''{ \voiceOne c4. g8 c2 | }
    \new Voice = "alto" \relative c' { \voiceTwo c4 b c( bes) | }
    \new NullVoice = "xyz" \relative c' { c4 b c2 | }
  >>
  \lyricsto "xyz" \new Lyrics \lyricmode {Glo -- ri -- a __ }
>>

Here, if I'm not mistaken, as the lyrics are associated with NullVoice
"xyz", the extender should end before, but it acts as if it was
associated with "alto" voice instead. The extender looks the same if I
define "xyz" as :
\new NullVoice = "xyz" \relative c'' { c4. g8 c2 | }
(melodie notes)

I rather like this behaviour of having the lyric extender lasting to
match the melismata of other voices (was trying to do something like
this), but I don't understand why it does so here, as this behaviour
is not systematic.

Should I add it as a comment to the issue you created last time, or
report it as a new one ?

Yann