1.71.0 polygon operation crashed due to 64bit integer overflow

[lei-yin]

In 1.71.0, the coordinate_traits specialized for polygon_long_long_type. On 64bit platform, when checking one point is above or below a line for arbitrary formation, it involves 64bit integer multiplication. When input geometry coordinate is really big, this operation can lead to 64bit integer overflow and caused crash.

[lei-yin]

Here is my proposed fix in isotropy.hpp:

#ifdef BOOST_POLYGON_USE_LONG_LONG
  template <>
  struct coordinate_traits<__int128> {
    typedef __int128 coordinate_type;
    typedef long double area_type;
    typedef __int128 manhattan_area_type;
    typedef unsigned __int128 unsigned_area_type;
    typedef __int128 coordinate_difference;
    typedef long double coordinate_distance;
  };

  template <>
  struct coordinate_traits<polygon_long_long_type, (sizeof(polygon_long_long_type)>sizeof(long) && sizeof(polygon_long_long_type)<sizeof(__int128))> {
    typedef polygon_long_long_type coordinate_type;
    typedef long double area_type;
    typedef polygon_long_long_type manhattan_area_type;
    typedef polygon_ulong_long_type unsigned_area_type;
    typedef polygon_long_long_type coordinate_difference;
    typedef long double coordinate_distance;
  };

  template <>
  struct coordinate_traits<polygon_long_long_type, sizeof(polygon_long_long_type) == sizeof(long)> {
    typedef polygon_long_long_type coordinate_type;
    typedef long double area_type;
    typedef __int128 manhattan_area_type;
    typedef unsigned __int128 unsigned_area_type;
    typedef polygon_long_long_type coordinate_difference;
    typedef long double coordinate_distance;
  };

  template<>
  struct coordinate_traits<long, sizeof(long) == sizeof(polygon_long_long_type)> {
    typedef coordinate_traits<polygon_long_long_type> cT_;
    typedef cT_::coordinate_type coordinate_type;
    typedef cT_::area_type area_type;
    typedef cT_::manhattan_area_type manhattan_area_type;
    typedef cT_::unsigned_area_type unsigned_area_type;
    typedef cT_::coordinate_difference coordinate_difference;
    typedef cT_::coordinate_distance coordinate_distance;
  };
#endif