Steps to reproduce:
- Go to https://doc.wikimedia.org/oojs-ui/master/js/#!/api/OO.ui.DropdownWidget
- Confirm in the Live Preview that the dropdown behaves as expected.
- Edit the code to include the line $overlay: $( 'body' ), to the config of the DropdownWidget.
- View Live Preview again.
Expected: As before.
Actual: At the bottom of the dropdown menu there is a small gray bar, the menu also is a few pixels to wide.