id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
9828,boost::geometry::union_(...) creates redundant closing point,Volker Schöch <vschoech@…>,Barend Gehrels,"Polygons created by boost::geometry algorithms should conform to the same rules as the input. In the following example, boost::geometry::union_ takes two simple, non-empty rectangular polygons and creates a polygon with a redundant closing point. My polygon type is oriented '''counter-clockwise''' and '''not closed''', my point type is based on '''int'''.

This is the data used as input to union:
{{{
_TPolygon<int> const polygon =
	_TPolygon<int>(""MULTIPOLYGON(((3398 1759,3592 1759,3592 1893,3398 1893)))"")
	| _TPolygon<int>( ""MULTIPOLYGON(((3592 1893,3592 1759,3910 1759,3910 1893)))"" );
}}}

This is the resulting multi-polygon with the redundant closing point:
{{{
MULTIPOLYGON(((3592 1893,3398 1893,3398 1759,3592 1759,3910 1759,3910 1893,3592 1893)))
}}}

This is my code that wraps boost::geometry to implement the operator used above:
{{{
template<typename T>
template<typename Geometry>
_TPolygon< T > _TPolygon< T >::operator|(Geometry const& geometry) const
{
	_TPolygon< T > polygonOut;
	boost::geometry::union_(*this, geometry, polygonOut);

	// the following line fixes the problem but should not be necessary
	//boost::geometry::correct( polygonOut );

	return polygonOut;
}
}}}
",Bugs,closed,Boost 1.56.0,geometry,Boost 1.55.0,Problem,fixed,"union, multi-polygon, polygon, correct",mkaravel