From: Luca Heltai <luca.heltai@sissa.it>
Date: Wed, 27 Apr 2016 07:20:38 +0000 (+0200)
Subject: Added asserts to Manifold::get_normals_at_vertices
X-Git-Tag: v8.5.0-rc1~1073^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1b1318519dd97cbb4f6a777d38c88c42ba0764e;p=dealii.git

Added asserts to Manifold::get_normals_at_vertices
---

diff --git a/source/grid/manifold.cc b/source/grid/manifold.cc
index 07ff568521..912b7516f8 100644
--- a/source/grid/manifold.cc
+++ b/source/grid/manifold.cc
@@ -185,8 +185,13 @@ get_normals_at_vertices (const Triangulation<2, 2>::face_iterator &face,
   n[0] = cross_product_2d(get_tangent_vector(face->vertex(0), face->vertex(1)));
   n[1] = -cross_product_2d(get_tangent_vector(face->vertex(1), face->vertex(0)));
 
-  n[0] /= n[0].norm();
-  n[1] /= n[1].norm();
+  for (unsigned int i=0; i<2; ++i)
+    {
+      Assert(n[i].norm() != 0, ExcInternalError("Something went wrong. The "
+                                                "computed normals have "
+                                                "zero length."));
+      n[i] /= n[i].norm();
+    }
 }
 
 
@@ -213,7 +218,12 @@ get_normals_at_vertices (const Triangulation<3, 3>::face_iterator &face,
           get_tangent_vector(face->vertex(3), face->vertex(1)));
 
   for (unsigned int i=0; i<4; ++i)
-    n[i] /=n[i].norm();
+    {
+      Assert(n[i].norm() != 0, ExcInternalError("Something went wrong. The "
+                                                "computed normals have "
+                                                "zero length."));
+      n[i] /=n[i].norm();
+    }
 }