From 95122cfbdd9df9ba7ab677c29f83bc9c7d3c3f4e Mon Sep 17 00:00:00 2001
From: maier <maier@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Sat, 1 Dec 2012 21:25:14 +0000
Subject: [PATCH] Add some Assertions, reindent

git-svn-id: https://svn.dealii.org/trunk@27721 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/source/dofs/dof_tools.cc | 43 +++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/deal.II/source/dofs/dof_tools.cc b/deal.II/source/dofs/dof_tools.cc
index 4e28cc84a7..e6133255f6 100644
--- a/deal.II/source/dofs/dof_tools.cc
+++ b/deal.II/source/dofs/dof_tools.cc
@@ -3303,15 +3303,24 @@ namespace DoFTools
   {
     static const int dim = FaceIterator::AccessorType::dimension;
 
-    Assert( (dim != 1)
-            ||
-            (face_orientation == true && face_flip == false && face_rotation == false),
-            ExcMessage ("The supplied orientation (face_orientation, face_flip, face_rotation) is invalid for 1D"));
-
-    Assert( (dim != 2)
-            ||
-            (face_orientation == true && face_rotation == false),
-            ExcMessage ("The supplied orientation (face_orientation, face_flip, face_rotation) is invalid for 2D"));
+    Assert( (dim != 1) ||
+                (face_orientation == true &&
+                 face_flip == false &&
+                 face_rotation == false),
+            ExcMessage ("The supplied orientation "
+                        "(face_orientation, face_flip, face_rotation) "
+                        "is invalid for 1D"));
+
+    Assert( (dim != 2) ||
+                (face_orientation == true &&
+                 face_rotation == false),
+            ExcMessage ("The supplied orientation "
+                        "(face_orientation, face_flip, face_rotation) "
+                        "is invalid for 2D"));
+
+    Assert(face_1 != face_2,
+           ExcMessage ("face_1 and face_2 are equal! Cannot constrain DoFs "
+                       "on the very same face"));
 
     Assert(face_1->at_boundary() && face_2->at_boundary(),
            ExcMessage ("Faces for periodicity constraints must be on the boundary"));
@@ -3502,15 +3511,18 @@ namespace DoFTools
             ExcMessage ("This function can not be used with distributed triangulations."
                         "See the documentation for more information."));
 
+    Assert (b_id1 != b_id2,
+            ExcMessage ("The boundary indicators b_id1 and b_id2 must be"
+                        "different to denote different boundaries."));
+
     typedef typename DH::face_iterator FaceIterator;
     typedef std::map<FaceIterator, std::pair<FaceIterator, std::bitset<3> > > FaceMap;
 
     // Collect matching periodic cells on the coarsest level:
-    FaceMap matched_cells = GridTools::collect_periodic_face_pairs(dof_handler,
-                                                                   b_id1,
-                                                                   b_id2,
-                                                                   direction,
-                                                                   offset);
+    FaceMap matched_cells =
+      GridTools::collect_periodic_face_pairs(dof_handler,
+                                             b_id1, b_id2,
+                                             direction, offset);
 
     // And apply the low level make_periodicity_constraints function to
     // every matching pair:
@@ -3529,6 +3541,9 @@ namespace DoFTools
                 face_2->boundary_indicator() == b_id2,
                 ExcInternalError());
 
+        Assert (face_1 != face_2,
+                ExcInternalError());
+
         make_periodicity_constraints(face_1,
                                      face_2,
                                      constraint_matrix,
-- 
2.39.5