Fix periodic BC bug

library/SpatialDomains/MeshGraph.cpp

@@ -2370,26 +2370,6 @@ namespace Nektar
                         {
                             m_expansionMapShPtrMap["DefaultVar"] = expansionMap;
                         }
-
-                        // // loop over all elements and set expansion
-                        // for(k = 0; k < fielddef.size(); ++k)
-                        // {
-                        //     for(int h = 0; h < fielddef[k]->m_fields.size(); ++h)
-                        //     {
-                        //         if(fielddef[k]->m_fields[h] == field)
-                        //         {
-                        //             expansionMap = m_expansionMapShPtrMap.find(field)->second;
-                        //             LibUtilities::BasisKeyVector def;
-
-                        //             for(int g = 0; g < fielddef[k]->m_elementIDs.size(); ++g)
-                        //             {
-                        //                 ExpansionShPtr tmpexp =
-                        //                         MemoryManager<Expansion>::AllocateSharedPtr(geom, def);
-                        //                 (*expansionMap)[fielddef[k]->m_elementIDs[g]] = tmpexp;
-                        //             }
-                        //         }
-                        //     }
-                        // }
                     }
                 }
             }

utilities/NekMesh/InputModules/InputNek5000.cpp

@@ -442,6 +442,8 @@ void InputNek5000::Process()
     // Boundary conditions: should be precisely nElements * nFaces lines to
     // read.
     int lineCnt = 0;
+    int perIn = 0, perOut = 0;
+
     while (m_mshFile.good())
     {
         getline(m_mshFile, line);
@@ -560,14 +562,18 @@ void InputNek5000::Process()
                     setup = true;
                 }
 
-                if (periodicIn.find(make_pair(perElmt, perFace)) !=
-                    periodicIn.end())
+                bool hasIn = periodicIn.find(make_pair(perElmt, perFace)) !=
+                    periodicIn.end();
+
+                if (hasIn)
                 {
                     swap(periodicInId, periodicOutId);
+                    perOut++;
                 }
                 else
                 {
                     periodicIn.insert(make_pair(elmt, side));
+                    perIn++;
                 }
 
                 std::string periodicInStr = "[" +
@@ -604,6 +610,12 @@ void InputNek5000::Process()
                     m_mesh->m_condition[periodicInId] = c;
                     m_mesh->m_condition[periodicOutId] = c2;
                 }
+
+                if (hasIn)
+                {
+                    swap(periodicInId, periodicOutId);
+                }
+
                 break;
             }
 
@@ -701,6 +713,11 @@ void InputNek5000::Process()
              << "from Nek5000 input file." << endl;
     }
 
+    if (perIn != perOut)
+    {
+        cerr << "Warning: number of periodic faces does not match." << endl;
+    }
+
     m_mshFile.reset();
 
     // -- Process rest of mesh.