Note spacing with a polyphonic grace notes

[Pierre Perol-Schneider]

Hi List,

Please consider those two snippets -- with a possible workaround in order to reach the wanted spacing:

\version "2.19.83"
\fixed c' {
  \voiceOne s4.
  \grace {
    <<
      { g,32
        -\shape #'((0 . 0)(0 . 0)(2 . 0)(2.5 . 2))
        _( g b \once\textLengthOn  f')
        % -\markup "  " % <= workaround?
      } \\
      { g,8 }
    >>
  } a'16. 32
}
\fixed c' {
  \voiceOne s4.
  \once\slurDown
  \appoggiatura { g,32 g b f' } a'16. 32
}

Is there another workaround?

Is it a known bug (I could not find it)?

Cheers,

Pierre