Different choice of normal, not really better

- perfect for `cube_quad.off`,
- but not for `mpi.off`.

The truth is out there.

.gitignore

@@ -1212,8 +1212,8 @@ gmon.*
 Polygonal_surface_reconstruction/examples/build*
 Polygonal_surface_reconstruction/test/build*
 Solver_interface/examples/build*
-dump-bug_point.xyz
-dump-bug.binary.cgal
-dump_region_with_size_2.polylines.txt
-dump_region.polylines.txt
+dump-*.xyz
+dump-*.binary.cgal
+dump_*.txt
+dump_*.off
 all_segments.polylines.txt

Triangulation_3/include/CGAL/Constrained_Delaunay_triangulation_3.h

@@ -373,9 +373,9 @@ public:
                                      vector(last_point, tr.point(*next_it))));
       }
       if (accumulated_normal.z() < 0 ||
-          (accumulated_normal.z() == 0 && accumulated_normal.y() < 0) ||
+          (accumulated_normal.z() == 0 && accumulated_normal.y() > 0) ||
           (accumulated_normal.z() == 0 && accumulated_normal.y() == 0 &&
-           accumulated_normal.x() < 0)
+           accumulated_normal.x() > 0)
           )
       {
         accumulated_normal = - accumulated_normal;