[OSM-dev] Moving to stricter multipolygon parsing

[Derick Rethans]

On Fri, 13 Jun 2014, Peter Wendorff wrote:

> IMHO, and that's what most bothers me at the old interpretation of
> multipolygons, any tag that belongs to a closed way should be valid for
> that closed way.
> We don't inherit names from streets to bus route relations - why should
> we do so for names of polygons to multipolygons?
> 
> Therefore my interpretation is, and IMHO it's the most intuitive
> interpretation, that the multipolygon relation describes "it's own"
> geometry, by referring to other objects (!) geometries, where these
> other objects may be features on their own or not.
> That means: Tags that are used on an outer closed way of a multipolygon
> relation should hold for the area enclosed by that way.
> Tags that are used on  an outer non-closed way of a multipolygon
> relation should hold for that way, which is not closed and doesn't get
> more closed by other ways somehow related to it by a multipolygon.
> 
> For inner member ways it's basically the same.

I would agree with this. I've recently mapped an Open Space, and tagged 
on the outer way of its MP the name= tag. The MP itself has one outer, 
and two inner ways to form landuse=forest, but both the inner ways are 
also landuse=grass. I've always thought that that is the right way to do 
things.

cheers,
Derick