ENH: mapDistribute: allow -1 as global element

src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C

@@ -307,7 +307,7 @@ Foam::mapDistribute::mapDistribute
         {
             label globalIndex = elements[i];
 
-            if (!globalNumbering.isLocal(globalIndex))
+            if (globalIndex != -1 && !globalNumbering.isLocal(globalIndex))
             {
                 label procI = globalNumbering.whichProcID(globalIndex);
                 nNonLocal[procI]++;
@@ -329,7 +329,7 @@ Foam::mapDistribute::mapDistribute
         {
             label globalIndex = elements[i];
 
-            if (!globalNumbering.isLocal(globalIndex))
+            if (globalIndex != -1 && !globalNumbering.isLocal(globalIndex))
             {
                 label procI = globalNumbering.whichProcID(globalIndex);
                 label index = globalNumbering.toLocal(procI, globalIndex);
@@ -452,7 +452,7 @@ Foam::mapDistribute::mapDistribute
             {
                 label globalIndex = cCells[i];
 
-                if (!globalNumbering.isLocal(globalIndex))
+                if (globalIndex != -1 && !globalNumbering.isLocal(globalIndex))
                 {
                     label procI = globalNumbering.whichProcID(globalIndex);
                     nNonLocal[procI]++;
@@ -482,7 +482,7 @@ Foam::mapDistribute::mapDistribute
             {
                 label globalIndex = cCells[i];
 
-                if (!globalNumbering.isLocal(globalIndex))
+                if (globalIndex != -1 && !globalNumbering.isLocal(globalIndex))
                 {
                     label procI = globalNumbering.whichProcID(globalIndex);
                     label index = globalNumbering.toLocal(procI, globalIndex);
@@ -603,6 +603,10 @@ Foam::label Foam::mapDistribute::renumber
     const label globalI
 )
 {
+    if (globalI == -1)
+    {
+        return globalI;
+    }
     if (globalNumbering.isLocal(globalI))
     {
         return globalNumbering.toLocal(globalI);

src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H

@@ -123,7 +123,7 @@ public:
         );
 
         //- Construct from list of (possibly) remote elements in globalIndex
-        //  numbering. Determines compact numbering (see above) and
+        //  numbering (or -1). Determines compact numbering (see above) and
         //  distribute map to get data into this ordering and renumbers the
         //  elements to be in compact numbering.
         mapDistribute
@@ -133,7 +133,7 @@ public:
             List<Map<label> >& compactMap
         );
 
-        //- Special variant that works with the into sorted into bins
+        //- Special variant that works with the info sorted into bins
         //  according to local indices. E.g. think cellCells where
         //  cellCells[localCellI] is a list of global cells
         mapDistribute