Don't try to unify dofs on lines when there are none. This happens for example for...

git-svn-id: https://svn.dealii.org/trunk@15984 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/deal.II/source/hp/dof_handler.cc b/deal.II/deal.II/source/hp/dof_handler.cc
index 081c9d397d9eff367226c2d381aac61e0e06c1a3..381747f7f664007333ef44c9853e3b5ce5432649 100644 (file)
--- a/deal.II/deal.II/source/hp/dof_handler.cc
+++ b/deal.II/deal.II/source/hp/dof_handler.cc
@@ -2,7 +2,7 @@
 //    $Id$
 //    Version: $Name$
 //
-//    Copyright (C) 2003, 2004, 2006, 2007 by the deal.II authors
+//    Copyright (C) 2003, 2004, 2006, 2007, 2008 by the deal.II authors
 //
 //    This file is subject to QPL and may not be  distributed
 //    without copyright and license information. Please refer
@@ -2378,9 +2378,11 @@ namespace hp
              const unsigned int fe_index_1 = line->nth_active_fe_index (f),
                                 fe_index_2 = line->nth_active_fe_index (g);
              
-             if ((*finite_elements)[fe_index_1].dofs_per_line
-                 ==
-                 (*finite_elements)[fe_index_2].dofs_per_line)
+             if (((*finite_elements)[fe_index_1].dofs_per_line
+                  ==
+                  (*finite_elements)[fe_index_2].dofs_per_line)
+                 &&
+                 ((*finite_elements)[fe_index_1].dofs_per_line > 0))
                {
                  internal::hp::ensure_existence_of_dof_identities<dim,1>
                    ((*finite_elements)[fe_index_1],