Iterating over elements with Alt+right in score with MM rest shows weird barlines, crash is possible
1) Create a new score.
2) Turn MM rests on.
3) Start iterating over elements with Alt+right.
Alternative: select the last bar line and press Alt+right.
Result: at the top of the page barlines with grips are drawn. Trying to drag those grips leads to a crash.
This is a partial regression in 3.4 version: in 3.3.4 those barlines were selected (which doesn't seem like it should happen) but were not shown and did not make it possible to crash MuseScore.