message: In the Mesh constructor from the given primary data, only use the
  value of 'boundary_type' when 'num_boundary_elements > 0'.
diff: @@ -2441,7 +2441,8 @@ Mesh::Mesh(double *_vertices, int num_vertices,
  num_boundary_elements);
  int element_index_stride = Geometry::NumVerts[element_type];
  - int boundary_index_stride = Geometry::NumVerts[boundary_type];
  + int boundary_index_stride = num_boundary_elements > 0 ?
  + Geometry::NumVerts[boundary_type] : 0;
  // assuming Vertex is POD
  vertices.MakeRef(reinterpret_cast<Vertex*>(_vertices), num_vertices);
  