clicking object with opaque background selects object behind it instead

1. Add a rehearsal marking to the first measure of the second system on the page. The marking should now be on top of the measure number at the beginning of the system.
2. Right-click the rehearsal mark and set the frame background color to #ffffff, alpha 255 (fully opaque). The rehearsal mark and its white background now completely cover the measure number.
3. Click in the center of the rehearsal mark.

Result: the not-visible measure number is selected rather than the rehearsal mark.

Proposal: an object with a non-transparent frame background should always be selected when clicked, never an object behind it. Basically, if a user can't see an object, it shouldn't be selected ahead of a visible object.