Fix spherical manifold at origin

diff --git a/source/grid/manifold_lib.cc b/source/grid/manifold_lib.cc
index 74d8a5023dc3682dbbb64557ea407bbd8f078a55..1fccfef375ebaa5fb516f0a052bd2075029fadde 100644 (file)
--- a/source/grid/manifold_lib.cc
+++ b/source/grid/manifold_lib.cc
@@ -291,7 +291,12 @@ get_new_point (const ArrayView<const Point<spacedim>> &vertices,
     }
 
   // Unit norm direction.
-  candidate /= candidate.norm();
+  const double norm = candidate.norm();
+
+  if (norm == 0)
+    return center;
+
+  candidate /= norm;
 
   return center+rho*candidate;
 }