id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
13494	polygon intersection fails	lehnert@…	Barend Gehrels	"Hello,

executing the following polygon intersection produces an empty result although the second operand is completely inside the first.

Code snippet:
    using point_type = boost::geometry::model::d2::point_xy<double>;
    using polygon = boost::geometry::model::polygon<point_type>;
    using multi_polygon = boost::geometry::model::multi_polygon<polygon>;

    polygon op1, op2;
    multi_polygon result;
   

    boost::geometry::read_wkt(""POLYGON((-1.99900000000000011 -0.889961757413527343,-1.99900000000000011 -1.12178395051169733,-1.89792526415373097 -1.49900000000000011,-1.8358086947169705 -1.49900000000000011,-1.99900000000000011 -0.889961757413527343))"", op1);
    boost::geometry::read_wkt(""POLYGON((-1.97591538973459313 -1.20793688888334905,-1.92415157993614439 -1.40112205701807624,-1.8661960316547388 -1.38559291465704759,-1.91795984145318754 -1.19240774652231996,-1.97591538973459313 -1.20793688888334905))"", op2);
    boost::geometry::intersection(op1, op2, result);

I could track down the problem to the intersection/touch part.
We use the intersection code quite heavily and such a constellation can occur frequently in our application. (I could present several more sample data for this bug). Therefore I set this to showstopper. 
Also I found other entries which look quite similar."	Bugs	new	To Be Determined	geometry	Boost 1.66.0	Showstopper		geometry intersection