Grace note playback does not stop (regression)

In the attached score, playback of the grace note is sustained for the duration of the "main" note.

Steps to reproduce:

1. Create a new score, using for example violin or trumpet
2. Add a whole note to the first measure, a different whole note to the second measure
3. Add a grace note (acciaccatura or appoggiatura) to the second note
4. Playback the score

Expected result: Grace note playback completes before the note it is attached to
Actual result: Grace note playback continues until there are no more notes to play.

tested using r1978