Restore meshOldPoints checkpoint outside of fvMesh.movePoints.

Calling `(void)mesh_.onDemandField()` before `fvMesh.movePoints()` does not clear the old geometry fields.

Author: vidulejs

Adapter.C

@@ -789,20 +789,14 @@ void preciceAdapter::Adapter::reloadMeshPoints()
         return;
     }
 
-    // Invalidate on-demand fields
-    // fvMesh::updateGeomNotOldVol()
-    // (void)mesh_.V();
-    (void)mesh_.Sf();
-    (void)mesh_.magSf();
-    (void)mesh_.C();
-    (void)mesh_.Cf();
-
-    // fvMesh.movePoints overwrites the pointer to the oldPoints
-    const_cast<pointField&>(mesh_.points()) = *meshOldPoints_;
-
     // Reload mesh points
     const_cast<Foam::fvMesh&>(mesh_).movePoints(*meshPoints_);
 
+    // polyMesh.movePoints will only update oldPoints
+    // if (curMotionTimeIndex_ != time().timeIndex())
+    // I.e., first implicit iteration
+    const_cast<pointField&>(mesh_.oldPoints()) = *meshOldPoints_;
+
     readMeshCheckpoint();
 
     DEBUG(adapterInfo("Moved mesh points to their previous locations."));