Re: [Lilypond-auto] Issue 3091 in lilypond: grace notes break preceding ties in MIDI

[lilypond]

Updates:
        Status: Started
        Owner: address@hidden
        Labels: Patch-new

Comment #4 on issue 3091 by address@hidden: grace notes break  
preceding ties in MIDI
http://code.google.com/p/lilypond/issues/detail?id=3091#c4

fix handling of grace notes to shorten preceding tied notes correctly

In Note_performer::process_music(), when a grace note was encountered,
the immediately preceding Audio_note (or Audio_notes if the grace note
followed a chord) was/were shortened, but it failed to check whether the
Audio_note is part of a tie.  Ensure that any note being shortened in
this way is the head of a tie, if it is part of a tie.

https://code.google.com/p/lilypond/issues/detail?id=3091

The following refactorings were also done in separate commits:

- extract new Audio_note::tie_head() method

  This makes it easy to retrieve the first note in a tie,
  and will be used in the fix for issue #3091.

- use Audio_note::get_column() rather than directly accessing the member  
field

  This adheres to the principle of encapsulation.

Finally, I implemented Audio_note::to_string() which came in handy
whilst I was debugging, and I thought it would be worth keeping this
for future debugging even though it's not used by the new code.

http://codereview.appspot.com/7108043