message: LOR bugfix when restriction matrix is non-NULL
  Ensure R and P are built when calling CopyProlongationAndRestriction
diff: @@ -3205,6 +3205,9 @@ void ParFiniteElementSpace::CopyProlongationAndRestriction(
  MFEM_VERIFY(P == NULL, "");
  MFEM_VERIFY(R == NULL, "");
  + // Ensure R and P matrices are built
  + pfes->Dof_TrueDof_Matrix();
  +
  SparseMatrix *perm_mat = NULL, *perm_mat_tr = NULL;
  if (perm)
  {
  