Slur from one voice to another emits warning

[Knute Snortum]

I am trying to get a slur that goes from one voice to another.  I've found examples in the docs and the LSR, but I am still getting warnings, even though the output is correct.  Here's a smallish example:

------------------------------------

\version "2.19.61"

\language "english"

hideOneNote = {

  \once \omit Stem

  \once \omit Flag

}

\relative {

  \key ef \major

  \time 3/4

  <<

    {

      | f''4-> s2

      | d4 

    }

    \\

    {

      | r8 f, ^( <e g> <ef a> <d bf'> <c c'> 

      % \stemUp % doesn't help

      | << \hideOneNote d'8 ) r >> % works, emits warning

      %| << \hide Stem \hide Flag d'8 ) r >> % works, emits warning

      %| << \hideNotes d'8 ) \unHideNotes r >> % doesn't work

    }

  >>

}

-------------------------------

The warning says "warning: cannot have note heads and rests together on a stem."

I post to Mutopia so I can't have warnings.  Any thoughts?

---

Knute Snortum

(via Gmail)