BUG: cyclics handled inconsistently

src/parallel/decompose/decompositionMethods/decompositionMethod/decompositionMethod.C

@@ -289,16 +289,25 @@ void Foam::decompositionMethod::calcCSR
 
     forAll(pbm, patchI)
     {
-        if (isA<cyclicPolyPatch>(pbm[patchI]))
+        if
+        (
+            isA<cyclicPolyPatch>(pbm[patchI])
+         && refCast<const cyclicPolyPatch>(pbm[patchI]).owner()
+        )
         {
-            const unallocLabelList& faceCells = pbm[patchI].faceCells();
+            const cyclicPolyPatch& cycPatch = refCast<const cyclicPolyPatch>
+            (
+                pbm[patchI]
+            );
 
-            label sizeby2 = faceCells.size()/2;
+            const unallocLabelList& faceCells = cycPatch.faceCells();
+            const unallocLabelList& nbrCells =
+                cycPatch.neighbPatch().faceCells();
 
-            for (label faceI=0; faceI<sizeby2; faceI++)
+            forAll(faceCells, facei)
             {
-                label own = faceCells[faceI];
-                label nei = faceCells[faceI + sizeby2];
+                label own = faceCells[facei];
+                label nei = nbrCells[facei];
 
                 if (cellPair.insert(edge(own, nei)))
                 {
@@ -370,8 +379,11 @@ void Foam::decompositionMethod::calcCSR
                 label own = faceCells[facei];
                 label nei = nbrCells[facei];
 
-                adjncy[xadj[own] + nFacesPerCell[own]++] = nei;
-                adjncy[xadj[nei] + nFacesPerCell[nei]++] = own;
+                if (cellPair.insert(edge(own, nei)))
+                {
+                    adjncy[xadj[own] + nFacesPerCell[own]++] = nei;
+                    adjncy[xadj[nei] + nFacesPerCell[nei]++] = own;
+                }
             }
         }
     }