Local mesh refinement combined with the mesh smoothing is broken

[Murtazo Nazarov]

Local mesh refinement using "regular_cut" combined with mesh.smooth() gives the following error:

 *** -------------------------------------------------------------------------
*** Error: Unable to find edge for bisection.
*** Reason: Internal error in algorithm; bisection edge not found.
*** Where: This error was encountered inside RegularCutRefinement.cpp.
*** -------------------------------------------------------------------------

However, "recursive_bisection" works without any problem.

Here is the code to test:

#include <dolfin.h>

using namespace dolfin;

int main()
{
  // Create mesh of unit square
  UnitSquare unit_square(10, 10);
  Mesh mesh(unit_square);

  parameters["refinement_algorithm"] = "regular_cut";

  // Refine mesh close to x = (0.5, 0.5)
  Point p(0.5, 0.5);
  for (unsigned int i = 0; i < 2; i++)
  {
    // Mark cells for refinement
    MeshFunction<bool> cell_markers(mesh, mesh.topology().dim(), false);
    for (CellIterator c(mesh); !c.end(); ++c)
      {
        if (c->midpoint().distance(p) < 0.1)
          cell_markers[*c] = true;
      }

    mesh = refine(mesh, cell_markers);
    mesh.smooth(); // everything works if this line is disabled.
  }

  return 0;
}