[mkgmap-dev] Multipolygon broken without warning

Thu Nov 11 09:01:20 GMT 2010

On Thu, Nov 11, 2010 at 12:40:15AM -0800, aighes wrote:
>So it seems to be a tagging-problem. Befor I changed the lakes, 
>natural=water was tagged on the three outer ways. This means, that you 
>have three ways with a polygon-tag -> will cause errors.

Right, I see this difference in the FINE logging output:

(MultiPolygonRelation): 63240002.osm.gz: Construct multipolygon 
http://www.openstreetmap.org/browse/relation/302922 
[natural=water,type=multipolygon,name=Vanajavesi]
(MultiPolygonRelation): 63240002.osm.gz:   outer 
http://www.openstreetmap.org/browse/way/11286420 []
(MultiPolygonRelation): 63240002.osm.gz:   outer 
http://www.openstreetmap.org/browse/way/25551892 []
(MultiPolygonRelation): 63240002.osm.gz:   outer 
http://www.openstreetmap.org/browse/way/43149608 []

In yesterday's data, the natural=water would be missing from the 
multipolygon but present in the three outer members.

>Is there an easy way to find some more wrong multipolygons?

If the inverted triangle was caused by mkgmap closing unclosed polygons, 
I think that mkgmap should warn about the unclosed polygons. Is there 
any reason why it does not do so currently?

	Marko