[mkgmap-dev] low-res-opt branch: error message from ShapeSplitter for self-intersecting multipolygon

Mon Jun 7 08:22:03 BST 2021

Hi Ticker,

please check https://files.mkgmap.org.uk/download/512/63240024.o5m
with (unpatched) r4756 and these options --generate-sea=multipolygon,floodblocker --preserve-element-order --order-by-decreasing-area
--allow-reverse-merge  

Produces an error message
SCHWERWIEGEND (ShapeSplitter): e:\osm_out_work\norway\20210511_095323\63240024.o5m: Vertical split 36691968 failed on shape at http://www.openstreetmap.org/?mlat=65.979056&mlon=12.308790&zoom=17 Possibly a self-intersecting polygon
for this invalid multipolygon : https://www.openstreetmap.org/relation/5294624

The result doesn't look wrong, so I think there should either be no error message or we need code to remove those self-intersections or ignore invalid MP like that?

Gerd