barcheck bug in 2.1.16

[Erik Sandberg]

Hi,
The following produces an incorrect barcheck warning during MIDI output. Very 
small random changes in the \notes section will spoil the warning, e.g. 
replacing "a4.~a4 a8" by "a4. a".

Using 2.1.16, Pedro's package.

/erik

\version "2.1.16"
\score {
  \addlyrics 
    \notes {
      \time 6/8 a8 a8 a a4( a8) | a4.~a4 a8 |
      a8( a8.) a16 a8( a a) | a2. | a8. a16 a8 a4 a8 |
      a a a a4. | a8 
    }
    \context Lyrics \lyrics {
      a a a a a a a a a a a a a a a a a a a | a
    }

  \paper{}
  \midi {\tempo 4=100}
}

/tmp$ lilypond foo
lilypond (GNU LilyPond) 2.1.16
Running usr...
Now processing: `foo.ly'
Parsing...Interpreting music...[7]
Preprocessing graphical objects...
Calculating line breaks... [3][6][8]
paper output to `foo.tex'...

Interpreting music...
/tmp/foo.ly:12:44: warning: barcheck failed at: 5/8:
      a a a a a a a a a a a a a a a a a a a
                                            | a

MIDI output to `foo.midi'...
Track ...


Analyzing foo.tex...
Running latex...
Running dvips...
Running ps2pdf...
DVI output to `foo.dvi'...
MIDI output to `foo.midi'...
PDF output to `foo.pdf'...
PS output to `foo.ps'...