id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
16933	Building relations including all of their parts more than four faces	Davidleci	Davidleci	"If in a building relation there is no any building part component with less than five sides, then JOSM highlights the segments shared by those areas that have more sides. However, there are buildings whose parts have all of them without exception more than four sides.

In my opinion, JOSM should not report that kind of segments when checking:

[[Image(Building validation.png, 1000px)]]
"	enhancement	needinfo	normal		Core validator	latest		building:part area segments overlap