musescore/MuseScore — pull request #50 by heuchi (2012-08-24 13:45:52+00:00)
Title: Note::updateAccidental takes care of user accidentals

http://musescore.org/en/node/17827
User added accidentals, that affect pitch (flat2, flat, nat, sharp, sharp2) will change according to pitch changes of the note. Other user added accidentals (like quarter tones) still stay.