Merge branch 'nedelec' into nedelec

diff --cc include/deal.II/numerics/vector_tools.templates.h
index 5d04209f723d5a95477db0a9fe57703eb4998984,d8393727a9e6bdc7ebb043e45066027443dbb9c8..5e5ff781d36d684dd0c8eec5ed35e7ef648be70c
--- 1/include/deal.II/numerics/vector_tools.templates.h
--- 2/include/deal.II/numerics/vector_tools.templates.h
+++ b/include/deal.II/numerics/vector_tools.templates.h
@@@ -5406,19 -5408,23 +5404,23 @@@ namespace VectorTool
                                  fe.base_element(i).n_components();
          }
        else
-         {
-           // Assert that the FE is in fact an FE_Nedelec, so that the default
-           // base_indices == (0,0) is correct.
-           Assert((dynamic_cast<const FE_Nedelec<dim> *>(&cell->get_fe()) !=
-                   nullptr) ||
-                    (dynamic_cast<const FE_NedelecSZ<dim> *>(&cell->get_fe()) !=
-                     nullptr),
-                  ExcNotImplemented());
-         }
-       // Store degree as fe.degree-1
-       // For nedelec elements FE_Nedelec<dim> (0) returns fe.degree = 1.
-       // For FESystem get the degree from the base_element
-       // indicated by the first_vector_component
+         // The only other element we know how to deal with (so far) is
+         // FE_Nedelec, which has one base element and one copy of it
+         // (with 3 components). In that case, the values of
+         // 'base_indices' as initialized above are correct.
+         Assert((dynamic_cast<const FE_Nedelec<dim> *>(&cell->get_fe()) !=
+                 nullptr) ||
+                  (dynamic_cast<const FE_NedelecSZ<dim> *>(&cell->get_fe()) !=
+                   nullptr),
+                ExcNotImplemented());
+ 
+ 
 -      // Store the 'degree' of the Nedelec element as fe.degree-1 For
++      // Store the 'degree' of the Nedelec element as fe.degree-1. For
+       // Nedelec elements, FE_Nedelec<dim>(0) returns fe.degree = 1
+       // because fe.degree stores the *polynomial* degree, not the
+       // degree of the element (which is typically defined based on
+       // the largest polynomial space that is *complete* within the
+       // finite element).
        const unsigned int degree =
          fe.base_element(base_indices.first).degree - 1;