[OSM-talk] fixing multipolygons

[Jon Burgess]

On Sat, 2008-03-08 at 21:16 +0100, Robert Vollmert wrote:
> 393 relations
> 235 with non-closed ways
>   53 with less than two members
>   32 containing ways with less than two nodes
>   56 modified relations
> 
Examples of non-closed ways are relation 435 and 436. Both these have 2
ways which together could form a closed ring if the direction of one of
the ways was reversed. I think these were marked as multipolygons by the
0.4->0.5 conversion script since it could not form a closed ring with
the directions as they were. I think we need to fix up these into proper
closed ways and remove the multipolygon relation. 

Given your stats above this might effect about half the existing
multipolygon relations.

It just so happens that the existing multipolygon handling code in
osm2pgsql will convert these ways into a closed area for the Mapnik
rendering. I can not remember whether this was by accident or design but
it would be nice not to lose these areas.


	Jon