Chord symbols not created in linked parts if no note or rest

WIndows 7, GIT commit: d316a4d

1) Create score for 1 instrument
2) Click whole rest in measure 1
3) Ctrl+K, enter chord symbol
4) Esc
5) File / Parts, New All, OK
6) Double click chord symbol;
7) Space, add another chord (on beat 2)
8) Esc
9) View part

Result: chord not duplicated in part

Only chord symbols attached to segments containing notes or rests get duplicated in parts. The code in undoAddElement to duplicate the chord symbol in the linked staff does not create a new segment to hold the chord symbol. So even though the code goes through the motions of adding the element to the part, it does not appear, because its parent is set to 0.

I'm not confident about creating segments or I'd tackle this myself...