Problem found and fixed, thanks Even! https://github.com/libgeos/geos/commit/49ac5aa4
P > On Sep 17, 2020, at 9:02 AM, Paul Ramsey <pram...@cleverelephant.ca> wrote: > > > >> On Sep 17, 2020, at 8:50 AM, Martin Davis <mtncl...@gmail.com> wrote: >> >> Thanks for testing, Even. >> >> Interestingly, in JTS the test case you give below for >> OverlayNG.intersection actually returns the same result as the old code: >> >> MULTILINESTRING ((833978.557030887 0, 835092.849076364 0), (832864.275023695 >> 0, 833978.556808034 0)) >> >> So this is something to look into on the GEOS side. > > I have confirmed this happens in GEOS, with a little unit test, so it's > nothing to do with GDAL. Looks like a morning in the debugger awaits. > > P > > >> >> On Thu, Sep 17, 2020 at 4:39 AM Even Rouault <even.roua...@spatialys.com> >> wrote: >> >> >> The intersection of the input geometry with this multipolygon of 2 parts can >> be shown with: >> >> from osgeo import ogr >> >> # input geometry crossing the antimeridian (UTM 60N) >> geom = ogr.CreateGeometryFromWkt('LINESTRING(832864.275023695 >> 0,835092.849076364 0)') >> >> # multipolygon with one part left to the antimeridian, one part right >> geom2 = ogr.CreateGeometryFromWkt('MULTIPOLYGON (((832864.275023695 >> 0.0,833978.556808034 -0.000110682755987,833978.556808034 >> 0.0,833978.556808034 0.000110682755987,832864.275023695 0.0,832864.275023695 >> 0.0)),((835092.849076364 0.0,833978.557030887 >> -0.000110682755987,833978.557030887 0.0,833978.557030887 >> 0.000110682755987,835092.849076364 0.0,835092.849076364 0.0)))') >> >> # intersection >> print(geom.Intersection(geom2)) >> >> With OverlayNG, the following leads to a LINESTRING EMPTY, whereas with GEOS >> 3.8something, it leads to the expected result of >> MULTILINESTRING ((832864.275023695 0.0,833978.556808034 >> 0.0),(833978.557030887 0.0,835092.849076364 0.0)) >> _______________________________________________ >> geos-devel mailing list >> geos-devel@lists.osgeo.org >> https://lists.osgeo.org/mailman/listinfo/geos-devel > _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/geos-devel