musescore/MuseScore — pull request #566 by Isensee (2013-11-24 15:16:07+00:00)
Title: fix #23543: additional update for acidentals

This feature enables, that changing the accidental of any note is automatically valid for the whole measure from this note on.

Usage: Press the ALT-Key while performing any change of accidenteal (clicking on the symbols within the action bar, or dragging and dropping from the accidental palette, double-clicking there, or pressing the delete key to remove an accidental).