[mkgmap-dev] [PATCH v4] Multipolygon code enabled for overlapping lines

Mon Feb 15 19:58:26 GMT 2010

Hi WanMil,

> I downloaded the finland OSM dump from geofabrik from today (Feb
> 15th).
> I used splitter v105 and the areas.list file from
> http://www.polkupyoraily.net/osm/ to get three tiles.
> Then I tried that patch:
> * I got no warning for mp 404644
> * I got only one "unknown reason" warning for complete finland

What did you see above the "unknown reason" warning? I saw this when  
using yesterday’s dump and your patch applied on top of mkgmap r1569  
(IIRC):

2010/02/14 21:52:08 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Multipolygon http://www.openstreetmap.org/browse/relation/404644  
contains errors.
2010/02/14 21:52:08 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Polygon 4611686018427397822(178P :  
(23045442[43P],19548137[36P],19560742[66P],25581658[35P]) is not  
processed due to an unknown reason.

With today’s dump and mkgmap r1571, I see no such warning. I did not  
see a warning either with yesterday’s dump and r1569 (IIRC).

> Apart from improving handling on the tile boundaries (which will be  
> another main patch) I don't see anything to improve. Did you really  
> use the patch?

I think I did. I just retried mp_linesoverlapping_v4.patch with today’s  
dump, and sure enough, I do see the 'unknown reason' warning that I  
thought was for relation 404644:

2010/02/15 21:41:07 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Cannot join the following ways to closed polygons. Multipolygon  
http://www.openstreetmap.org/browse/relation/404644
2010/02/15 21:41:07 WARNING (MultiPolygonRelation): 63240001.osm.gz: -  
way: http://www.openstreetmap.org/browse/way/25581758
2010/02/15 21:41:08 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Multipolygon http://www.openstreetmap.org/browse/relation/404644  
contains errors.
2010/02/15 21:41:08 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Polygon 4611686018427397822(178P :  
(23045442[43P],19548137[36P],19560742[66P],25581658[35P]) is not  
processed due to an unknown reason.
2010/02/15 09:59:56 WARNING (MultiPolygonRelation): 63240002.osm.gz:  
Multipolygon http://www.openstreetmap.org/browse/relation/404644 does  
not contain any way tagged with role=outer.

OK, without the patch, I see one warnings for 404644 in 63240001.osm.gz  
and two in 63240002.osm.gz, most likely due to incorrect splitting.  
Here is the warning for 63240001.osm.gz:

2010/02/15 09:59:12 WARNING (MultiPolygonRelation): 63240001.osm.gz:  
Cannot join the following ways to closed polygons. Multipolygon  
http://www.openstreetmap.org/browse/relation/404644
2010/02/15 09:59:12 WARNING (MultiPolygonRelation): 63240001.osm.gz: -  
way: http://www.openstreetmap.org/browse/way/25581758

Can you figure out what is behind the 'unknown reason' if it is not the  
incorrectly split relation 404644?

	Marko