Incorrect placement of \grace with \repeat in combination with nested Staff

[Ronald Pijnacker]

> I'm not top posting


Hi all,

The following piece of lilypond gives a somewhat unexpected result:
The grace-note ends up in a measure by itself.

----
\new PianoStaff <<
  \new Staff <<
    {
      \relative c' { c1 }
      \repeat volta 2 { \relative c' { \grace c8 c1 } }
    }
  >>
  \new Staff <<
    {
      \relative c' { c1 }
      \repeat volta 2 { \relative c' { c1 } }
    }
  >>
>>
\version "2.12.3"
----

Best regards,

Ronald