[gdal-dev] 'Polygons as multipolygons' option for OSM driver

[Jukka Rahkonen]

In OSM data same sort of polygon features are typically modelled either as
closed rings or as multipolygon relations if they happen to have holes or if the
length of the outer ring exceeds the limit of 2000 nodes.

For making rendering more simple the OGR driver might have an option for
skipping the polygon layer. In that case features which are found from the list
'closed_ways_are_polygons' in osmconf.ini would take attributes from the
[multipolygons] section instead of [polygons]. Results would be written into the
multipolygons table and geometry type of these features would be multipolygon. 

Place of the control could be just below the 'closed_ways_are_polygons' control.
It might have an understandable name like 'write_polygons_as_multipolygons' and
it could take values yes/no. As a comment there might be something like

# Uncomment to write also simple polygons into 'multipolygons' table
# If selected the 'polygons' table will not be created
# and all the polygons will take their attributes from the [multipolygons]
# section below

Does this feel reasonable?

-Jukka Rahkonen-