[geos-devel] [GEOS] #1031: Union of two Polygons results in GeometryCollection

[GEOS]

#1031: Union of two Polygons results in GeometryCollection
------------------------+--------------------------
 Reporter:  brownjt     |      Owner:  geos-devel@…
     Type:  defect      |     Status:  new
 Priority:  minor       |  Milestone:
Component:  Default     |    Version:  3.8.0
 Severity:  Unassigned  |   Keywords:
------------------------+--------------------------
 {{{
 #include <geos/io/WKBReader.h>
 #include <sstream>
 #include <cassert>

 int main()
 {
     std::string a =
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     std::string b =
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     std::istringstream sa(a);
     std::istringstream sb(b);
     geos::io::WKBReader reader;

     std::unique_ptr<geos::geom::Geometry> ga = reader.readHEX(sa);
     assert(ga->isValid());
     assert(ga->getGeometryTypeId() == geos::geom::GEOS_POLYGON);

     std::unique_ptr<geos::geom::Geometry> gb = reader.readHEX(sb);
     assert(gb->isValid());
     assert(gb->getGeometryTypeId() == geos::geom::GEOS_POLYGON);

     std::unique_ptr<geos::geom::Geometry> gc = ga->Union(gb.get());
     assert(gc->isValid());
     geos::geom::GeometryTypeId type = gc->getGeometryTypeId();
     std::cout << type << std::endl;
     assert(type == geos::geom::GEOS_POLYGON);
 }
 }}}


 Expected: result geometry is a Polygon

 Actual: result is a GeometryCollection which contains the expected Polygon
 as well as an extraneous LineString consisting of two points.

-- 
Ticket URL: <https://trac.osgeo.org/geos/ticket/1031>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).