vocalName isn't visible in the output

[Lukas Sommer]

> I'm not top posting.
% Bug report: The "vocalName" of the Lyrics context isn't visible in the
output: The text "myvocalname" should appear in the output, but it doesn't.
% The problem seems to occur as long as the corresponding voice (here
"myvoice") starts with a rest: If you remove "r2" than "myvocalname" appears
correctly in the output.
\version "2.16"
\score { <<
      \context Staff << \context Voice = myvoice { r2 a2 }  >>
      \context Lyrics \lyricsto myvoice  \lyricmode {  \set vocalName =
#"myvocalname" mylyrics }
>> }