From 934fa98b9788dde1af01b7aed30e4e7fbfea771a Mon Sep 17 00:00:00 2001
From: Henry Weller <http://cfd.direct>
Date: Fri, 25 Jun 2021 18:11:20 +0100
Subject: [PATCH] fvMesh::updateMesh: Only store the old-time volumes if they
 are already present

i.e. if mesh-morphing is active
---
 .../fvMeshDistribute/fvMeshDistribute.C       | 12 +++++++++++
 src/finiteVolume/fvMesh/fvMesh.C              | 20 ++++++++++++-------
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C b/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
index febb59149a..dde37093dd 100644
--- a/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
+++ b/src/dynamicMesh/fvMeshDistribute/fvMeshDistribute.C
@@ -1588,6 +1588,10 @@ void Foam::fvMeshDistribute::sendMesh
         << mesh.faceNeighbour()
         << mesh.boundaryMesh()
 
+        //*** Write the old-time volumes if present
+        // << mesh.V0().field()
+        // << mesh.V0().field()
+
         << zonePoints
         << zoneFaces
         << zoneFaceFlip
@@ -1632,6 +1636,10 @@ Foam::autoPtr<Foam::fvMesh> Foam::fvMeshDistribute::receiveMesh
     labelList domainAllNeighbour(fromNbr);
     PtrList<entry> patchEntries(fromNbr);
 
+    //*** Read the old-time volumes if present
+    // scalarField V0(fromNbr);
+    // scalarField V00(fromNbr);
+
     CompactListList<label> zonePoints(fromNbr);
     CompactListList<label> zoneFaces(fromNbr);
     CompactListList<bool> zoneFaceFlip(fromNbr);
@@ -1681,6 +1689,10 @@ Foam::autoPtr<Foam::fvMesh> Foam::fvMeshDistribute::receiveMesh
     // Add patches; no parallel comms
     domainMesh.addFvPatches(patches, false);
 
+    //*** Set the old-time volumes if present
+    // domainMesh.setV0().field() = V0;
+    // domainMesh.setV00().field() = V00;
+
     // Construct zones
     List<pointZone*> pZonePtrs(pointZoneNames.size());
     forAll(pZonePtrs, i)
diff --git a/src/finiteVolume/fvMesh/fvMesh.C b/src/finiteVolume/fvMesh/fvMesh.C
index f980b2661f..c944d99fcd 100644
--- a/src/finiteVolume/fvMesh/fvMesh.C
+++ b/src/finiteVolume/fvMesh/fvMesh.C
@@ -799,9 +799,12 @@ void Foam::fvMesh::updateMesh(const mapPolyMesh& mpm)
 
     if (VPtr_)
     {
-        // Grab old time volumes if the time has been incremented
-        // This will update V0, V00
-        storeOldVol(mpm.oldCellVolumes());
+        // Cache old time volumes if they exist and the time has been
+        // incremented.  This will update V0, V00
+        if (V0Ptr_)
+        {
+            storeOldVol(mpm.oldCellVolumes());
+        }
 
         // Few checks
         if (VPtr_ && (V().size() != mpm.nOldCells()))
@@ -854,10 +857,13 @@ void Foam::fvMesh::updateMesh(const mapDistributePolyMesh& mdpm)
 
     // if (VPtr_)
     // {
-    //     // Grab old time volumes if the time has been incremented
-    //     // This will update V0, V00
-    //     storeOldVol(mdpm.oldCellVolumes());
-
+    //     // Cache old time volumes if they exist and the time has been
+    //     // incremented.  This will update V0, V00
+    //     if (V0Ptr_)
+    //     {
+    //         storeOldVol(mpm.oldCellVolumes());
+    //     }
+    //
     //     // Few checks
     //     if (VPtr_ && (V().size() != mdpm.nOldCells()))
     //     {