id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
11789,Boost 1.59.0: geometry::intersection() asserts for spherical_equatorial coordinate system,Dave Stacey <drstacey@…>,Barend Gehrels,"For disjoint polygons, geometry::intersection() assert()s when used with the spherical_equatorial coordinate system. assert() comes from geometry::math::detail::normalize_spheroidal_coordinates<>::apply(), as shown by the following code:

{{{
#include <iostream>
#include <deque>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/geometry/geometries/adapted/c_array.hpp>
#include <boost/foreach.hpp>

typedef boost::geometry::cs::spherical_equatorial<boost::geometry::degree> coordinate_system;
BOOST_GEOMETRY_REGISTER_C_ARRAY_CS(coordinate_system)

int main()
{
    typedef boost::geometry::model::point<double, 2, coordinate_system> point_t;
    typedef boost::geometry::model::polygon<point_t> polygon_t;

    double green_pts[][2] = {
        {-4.5726431789237223,52.142932977753595},
        {-4.5743166242433153,52.143359442355219},
        {-4.5739141406075410,52.143957260988416},
        {-4.5722406991324354,52.143530796430468},
        {-4.5726431789237223,52.142932977753595}};
    polygon_t green;
    boost::geometry::append(green, green_pts);

    double blue_pts[][2] = {
        {-4.5714644516017975,52.143819810922480},
        {-4.5670821923630358,52.143819810922480},
        {-4.5670821923630358,52.143649055226163},
        {-4.5714644516017975,52.143649055226163},
        {-4.5714644516017975,52.143819810922480}};
    polygon_t blue;
    boost::geometry::append(blue, green_pts);

    std::deque<polygon_t> output;
    // assert() comes from the following call...
    boost::geometry::intersection(green, blue, output);

    int i = 0;
    std::cout << ""green && blue:"" << std::endl;
    BOOST_FOREACH(polygon_t const& p, output)
    {
        std::cout << i++ << "": "" << boost::geometry::area(p) << std::endl;
    }

    return 0;
}
}}}

assert() is generated in the call to geometry::intersection(). Tested with both g++-4.9.3 and MSVC 2005 SP1. This is a regression on Boost 1.57.0, where the assert() is not produced.

assert() is only generated when using the cs::spherical_equatorial coordinate system; if cs::cartesian is used instead then the assert() is not generated.

Many thanks for your work on Boost and for looking at this ticket.",Bugs,closed,Boost 1.61.0,geometry,Boost 1.59.0,Problem,fixed,,