Fix search for a vertex location

diff --git a/source/grid/grid_tools.cc b/source/grid/grid_tools.cc
index 45317013248a63b9a965391c4890a9203c848dd2..72f3f6128460f0e022083f9c8a699e14480fec07 100644 (file)
--- a/source/grid/grid_tools.cc
+++ b/source/grid/grid_tools.cc
@@ -1623,7 +1623,10 @@ next_cell:
             vertex_to_point = p - mesh.get_vertices()[closest_vertex_index];
           }
 
-        vertex_to_point /= vertex_to_point.norm();
+        const double vertex_point_norm = vertex_to_point.norm();
+        if (vertex_point_norm > 0)
+          vertex_to_point /= vertex_point_norm;
+
         const unsigned int n_neighbor_cells = vertex_to_cells[closest_vertex_index].size();
 
         // Create a corresponding map of vectors from vertex to cell center