Select the first visible or selectable child of the menu shell; don’t select tearoff items unless the only item is a tearoff item.
if %TRUE, search for the first selectable menu item, otherwise select nothing if the first item isn’t sensitive. This should be %FALSE if the menu is being popped up initially.
2.2
See Implementation
Select the first visible or selectable child of the menu shell; don’t select tearoff items unless the only item is a tearoff item.