Long-standing bug: no ties were created

[Dr A V Le Blanc]

The following sample has failed to work as I expect since
Lilypond 1.4.8, at least, and still causes a problem with 1.6.6.
I apologise for not having sent it in earlier.

     -- Owen
     address@hidden

The source file, tmp.ly:

alto = \notes \relative c' {
  < d1 f, > ~ | < d2 f, > r |
}

\score {

  \notes \context Staff = treble <
        \key d \minor
        \time 2/2
        \clef violin
        \alto
  >

  \paper {
  }

  \midi {
        \tempo 2=40
  }
}

The log file:

Running LilyPond...
GNU LilyPond 1.6.6
Now processing: `tmp.ly'
Parsing...
Interpreting music...[3]
Preprocessing elements... 
Calculating column positions... warning: Too many clashing notecolumns.  
Ignoring them.

paper output to `tmp.tex'...

Interpreting music...
/tmp/tmp.ly:0:13: warning: No ties were created!:
  < d1 f, > ~
              | < d2 f, > r |

MIDI output to `tmp.midi'...
Track ... 
Analyzing tmp.tex...
Running LaTeX...
DVI output to `tmp.dvi'...
MIDI output to `tmp.midi'...