CGAL users discussion list

[William Taysom <>]

Hello,

I recently found a small example quadratic program (actually the objective is 
linear) which causes a segmentation fault.  The basic setup is as follows and 
a complete test file is attached.

== qp_segault (excerpt) ==

const int X = 0;
const int Y = 1;
const int Z = 2;

Quadratic_program<NT> qp;

void set_row(int i, NT x, NT y, NT z, Comparison_result rel, NT b) {
        qp.set_a(X, i, x);
        qp.set_a(Y, i, y);
        qp.set_a(Z, i, z);
        qp.set_r(i, rel);
        qp.set_b(i, b);
}

int main() {
        // Just try to minimize X
        // though the objective function doesn't make a difference.
        qp.set_c(X, 1);
        
        set_row(0, 1, 1, 1,  EQUAL, 4);
        set_row(1, 1, 1, 1, LARGER, 4);
        set_row(2, 1, 0, 1, LARGER, 3);
        set_row(3, 1, 1, 0, LARGER, 3);
        
        qp.set_u(X, true, 2);

        Quadratic_program_solution<ET> sol;
        sol = solve_quadratic_program(qp, ET());
        std::cout << sol;
}

==

Pretty much any change to the problem setup removes the segfault, but changes 
to the objective function, solution function, number type, and options do not.

I'm new to CGAL, and I've been very pleased with the API so far.  I hope we 
can work together to find the root cause of this segfault.

Best regards,
William

Attachment: qp_segfault.cpp
Description: Binary data