From e3ad28b7ff2b41f3c46716a7572575ab0589f600 Mon Sep 17 00:00:00 2001
From: Timo Heister <timo.heister@gmail.com>
Date: Sun, 12 Jun 2022 20:18:45 -0400
Subject: [PATCH] add test

---
 tests/data_out/data_out_hdf5_03.cc            | 91 +++++++++++++++++++
 ..._hdf5=true.with_p4est=true.mpirun=2.output |  5 +
 ..._hdf5=true.with_p4est=true.mpirun=3.output |  5 +
 3 files changed, 101 insertions(+)
 create mode 100644 tests/data_out/data_out_hdf5_03.cc
 create mode 100644 tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=2.output
 create mode 100644 tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=3.output

diff --git a/tests/data_out/data_out_hdf5_03.cc b/tests/data_out/data_out_hdf5_03.cc
new file mode 100644
index 0000000000..a345f165d8
--- /dev/null
+++ b/tests/data_out/data_out_hdf5_03.cc
@@ -0,0 +1,91 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2017 - 2021 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+// test parallel DataOut with HDF5
+//
+// When running with 3 MPI ranks, one of the ranks will have 0
+// cells. This tests a corner case that used to fail because the code
+// assumed that all ranks have at least one cell.
+
+#include <deal.II/base/mpi.h>
+
+#include <deal.II/distributed/tria.h>
+
+#include <deal.II/fe/fe_q.h>
+
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/tria.h>
+
+#include <deal.II/numerics/data_out.h>
+
+#include <string>
+#include <vector>
+
+#include "../tests.h"
+
+template <int dim>
+void
+test()
+{
+  parallel::distributed::Triangulation<dim> tria(MPI_COMM_WORLD);
+  std::vector<unsigned int>                 repetitions(dim, 1);
+  repetitions[0] = 2; // 2x1x1 cells
+  Point<dim> p1;
+  Point<dim> p2;
+  for (int i = 0; i < dim; ++i)
+    p2[i] = 1.0;
+  GridGenerator::subdivided_hyper_rectangle(tria, repetitions, p1, p2);
+  tria.refine_global(1);
+
+  FE_Q<dim> fe(1);
+
+  DoFHandler<dim> dof(tria);
+  dof.distribute_dofs(fe);
+
+  Vector<double> v1(dof.n_dofs());
+  for (unsigned int i = 0; i < v1.size(); ++i)
+    v1(i) = i;
+
+  DataOut<dim> data_out;
+  data_out.add_data_vector(dof, v1, "bla");
+  data_out.build_patches(1);
+
+  DataOutBase::DataOutFilter data_filter(
+    DataOutBase::DataOutFilterFlags(false, false));
+  data_out.write_filtered_data(data_filter);
+  data_out.write_hdf5_parallel(data_filter, "out.h5", MPI_COMM_WORLD);
+
+  if (Utilities::MPI::this_mpi_process(MPI_COMM_WORLD) == 0)
+    {
+      // Sadly hdf5 is binary and we can not use hd5dump because it might
+      // not be in the path.
+      std::ifstream f("out.h5");
+      AssertThrow(f.good(), ExcIO());
+      deallog << "ok" << std::endl;
+    }
+}
+
+
+
+int
+main(int argc, char *argv[])
+{
+  Utilities::MPI::MPI_InitFinalize mpi_initialization(argc, argv, 1);
+  MPILogInitAll                    all;
+
+
+  test<2>();
+  test<3>();
+}
diff --git a/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=2.output b/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=2.output
new file mode 100644
index 0000000000..1b4b05f75a
--- /dev/null
+++ b/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=2.output
@@ -0,0 +1,5 @@
+
+DEAL:0::ok
+DEAL:0::ok
+
+
diff --git a/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=3.output b/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=3.output
new file mode 100644
index 0000000000..1b4b05f75a
--- /dev/null
+++ b/tests/data_out/data_out_hdf5_03.with_hdf5=true.with_p4est=true.mpirun=3.output
@@ -0,0 +1,5 @@
+
+DEAL:0::ok
+DEAL:0::ok
+
+
-- 
2.39.5