Underscore and left-aligned lyric remain after undo

1. Open attached score (produced in 1.3).
2. Double-click lyric.
3. Press underscore.
4. Click elsewhere (leaving edit mode).
5. 'Edit'>'Undo'.

Result: The lyric is still left-aligned and the temporary underscore remains.

Note: It is also reproducible in a 2.0 score.

Using MuseScore 2.0 Nightly Build 04a5b28 - Mac 10.7.5.