[mkgmap-dev] Wishlist: Better multipolygon error reporting

Thu Jul 5 20:24:29 BST 2012

Hi,

Lake Päijänne is probably the largest multipolygon relation in Finland, 
even after I split some named bays to separate natural=bay polygons or 
multipolygons. There is one error that I have not been able to figure 
out. JOSM is not complaining anything if I extract the relation from 
finland.osm.pbf with Osmosis and load to JOSM. The whole area is fully 
within the boundaries of my tile 63240005:

2012/07/05 21:37:39 WARNING (MultiPolygonRelation): 63240005.osm.pbf: 
Multipolygon http://www.openstreetmap.org/browse/relation/1239779 
[natural=water,type=multipolygon,name=Päijänne] contains errors.
2012/07/05 21:37:39 WARNING (MultiPolygonRelation): 63240005.osm.pbf: 
Polygon 4611686018427683240(7P)(31081024[7P]) carries role inner but 
lies inside an inner polygon. Potentially its role should be outer.

Could the message mention a coordinate of the faulty polygon?

I am guessing that this message is due to the Garmin map resolution 
(about 5m). It would be nice to identify the problematic polygon, to 
confirm this. Or, maybe the JOSM Validator is not checking for inner 
polygons that are completely within another inner polygon.

	Marko