Segmentation fault on insert_segments of Segment Delaunay Graph using exact constructions kernel

[Yvee1]

Issue Details

Running the insert_segments function of Segment_Delaunay_graph_2 with the Exact_predicates_exact_constructions_kernel gives a segmentation fault.

The error occurs regardless of which segments are inserted. Inserting segments separately with insert after construct_site_2 works fine. When using the Exact_predicates_inexact_constructions_kernel, function insert_segments does work as expected.

Source Code

typedef CGAL::Exact_predicates_exact_constructions_kernel K;
typedef CGAL::Segment_Delaunay_graph_traits_2<K>          Gt;
typedef CGAL::Segment_Delaunay_graph_2<Gt>                SDG2;

int main() {
    auto segments = std::vector({
        CGAL::Segment_2<K>(
            CGAL::Point_2<K>(0.0, 0.0),
            CGAL::Point_2<K>(1.0, 0.0))
    });

    SDG2 delaunay;
    delaunay.insert_segments(segments.begin(), segments.end());

    return 0;
}

Environment

• Operating system (Windows/Mac/Linux, 32/64 bits): WSL2 on Windows 11, 64 bits
• Compiler: g++
• Release or debug mode: both give a segmentation fault
• CGAL version: 5.4-1
• Boost version: 1.74.0

[afabri]

I found the problem and fix, but note that ifor performance reasons it is not really a good idea to use the kernel which does exact constructions.

[Yvee1]

Thanks for looking into the issue! I used inexact constructions before, but I got an assertion error for some inputs, I think because of collinear points. Is there another way of resolving this aside from turning to exact constructions?

[afabri]

Would be great if you shared data for which you got an assertion, as well your typedefs, so that we can try to reproduce/fix.

[Yvee1]

I had some trouble with extracting a minimal example, but I have one now and have opened a new issue (#7978)