message: Handle the case of empty local mesh
diff: @@ -473,6 +473,7 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::MultTranspose(
  void L2ProjectionGridTransfer::L2ProjectionL2Space::Prolongate(
  const Vector &x, Vector &y) const
  {
  + if (fes_ho.GetNE() == 0) { return; }
  MFEM_VERIFY(P.Size() > 0, "Prolongation not supported for these spaces.")
  int vdim = fes_ho.GetVDim();
  Array<int> vdofs;
  @@ -509,6 +510,7 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::Prolongate(
  void L2ProjectionGridTransfer::L2ProjectionL2Space::ProlongateTranspose(
  const Vector &x, Vector &y) const
  {
  + if (fes_ho.GetNE() == 0) { return; }
  MFEM_VERIFY(P.Size() > 0, "Prolongation not supported for these spaces.")
  int vdim = fes_ho.GetVDim();
  Array<int> vdofs;
  