Can't turn visibility off for note dot

Context: commit c35b7424fb (2012-12-04)

Step:
1) Open or create a score with at least one dotted note
2) Select the dot
3) In Inspector, uncheck "Visible" for the dot

Result: the dot remains visible

Note: In fact, there is one line in Note::layout() (file libmscore/note.cpp, line 1261) which resets the dot visibility to its note visibility value each time the note is laid out. Why?