Not every sustainOn command works properly in midi output

[Michael Pozhidaev]

Hello!

I have noticed something strange, looks like a bug
with producing midi files for piano pieces.

It appears in lilypond 2.11.61 and 2.12.1 built from sources  for 64-bit linux
and lilypond 2.12.1 from the binary linux-x86_64 distribution.
Everything was OK in old lilypond-2.11.0 (but using \sustainDown command
instead of \sustainOn)

In the following snippet there are two marks, 1 and 2.
The \sustainOn command in the line below mark1 works properly, 
but the one below mark2 do nothing. In this message there is midi file I
got 
with this code. Is it a bug or I do something wrong?
Thanks!

\version "2.11.61"

partOneLeft = {
  \key c \minor
  \time 6/8
  \clef bass

  \tempo 4 = 140

  <f as c'>4. f'4( c'8
  f4 as2)
  <g b d'>4. g'4( d'8
  g4 b2)
  c4( es8 g4 c'8
  c2.)
}

partOneLeftMidi = {

%%mark1:
  s4. \sustainOn s4 s8
  s4 s2 

%%mark2:
  s4. \sustainOff \sustainOn s4 s8
  s4 s2

  s4 \sustainOff \sustainOn s8 s4 s8
  s2. \sustainOff
}

\score {
  \new PianoStaff <<
    \set PianoStaff.instrumentName = "piano"
    \new Staff = "lower" << 
      {
        \partOneLeft 
      }
      {
        \partOneLeftMidi 
      }
    >>
  >>
  \midi { }
}

-- 
Michael Pozhidaev. E-mail: address@hidden
Tomsk State University. http://www.csd.tsu.ru
ALT Linux Team. http://www.altlinux.ru

problem.midi
Description: Binary data