musescore/MuseScore — pull request #581 by Isensee (2013-12-05 13:42:13+00:00)
Title: fix #23543: aditional update accidentals 2

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).

I think, this version is better than the first one.