From 4ad708038d739f30ba8452d7a615ee7c21dc98a1 Mon Sep 17 00:00:00 2001
From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Mon, 6 Feb 2017 17:50:21 +0100
Subject: [PATCH] Add test for copying FilteredOperator

---
 include/deal.II/grid/filtered_iterator.h |  5 +++
 tests/grid/filtered_iterator_05.cc       | 50 ++++++++++++++++++++++++
 tests/grid/filtered_iterator_05.output   |  2 +
 3 files changed, 57 insertions(+)
 create mode 100644 tests/grid/filtered_iterator_05.cc
 create mode 100644 tests/grid/filtered_iterator_05.output

diff --git a/include/deal.II/grid/filtered_iterator.h b/include/deal.II/grid/filtered_iterator.h
index 22d6dff9aa..6aea724cb2 100644
--- a/include/deal.II/grid/filtered_iterator.h
+++ b/include/deal.II/grid/filtered_iterator.h
@@ -960,6 +960,11 @@ FilteredIterator<BaseIterator> &
 FilteredIterator<BaseIterator>::
 operator = (const FilteredIterator &fi)
 {
+  // Using equivalent code to the one for 'operator=(const BaseIterator &bi)'
+  // below, some compiler would not cast fi to the base class of type
+  // BaseIterator but try to go through constructing a new Accessor from fi
+  // which fails. Hence, we just use an explicit upcast and call the above-
+  // mentioned method.
   const BaseIterator &bi = fi;
   return operator = (bi);
 }
diff --git a/tests/grid/filtered_iterator_05.cc b/tests/grid/filtered_iterator_05.cc
new file mode 100644
index 0000000000..ed5a04dc81
--- /dev/null
+++ b/tests/grid/filtered_iterator_05.cc
@@ -0,0 +1,50 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2017 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 at
+// the top level of the deal.II distribution.
+//
+// ---------------------------------------------------------------------
+
+/*
+ * Test that copying a FilteredIterator works
+ */
+
+#include <deal.II/grid/tria.h>
+#include <deal.II/grid/filtered_iterator.h>
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/dofs/dof_handler.h>
+#include <deal.II/dofs/dof_accessor.h>
+#include "../tests.h"
+
+template<int dim>
+void
+test()
+{
+  Triangulation<dim> triangulation;
+  DoFHandler<dim> dof_handler(triangulation);
+  GridGenerator::hyper_cube(triangulation);
+
+  FilteredIterator<typename DoFHandler<dim>::level_cell_iterator> begin
+  (IteratorFilters::LocallyOwnedLevelCell(), dof_handler.begin());
+  FilteredIterator<typename DoFHandler<dim>::level_cell_iterator> end
+  (IteratorFilters::LocallyOwnedLevelCell(), dof_handler.end());
+  end = begin;
+
+  deallog << "OK" << std::endl;
+}
+
+int main()
+{
+  initlog();
+  test<2>();
+
+  return 0;
+}
diff --git a/tests/grid/filtered_iterator_05.output b/tests/grid/filtered_iterator_05.output
new file mode 100644
index 0000000000..0fd8fc12f0
--- /dev/null
+++ b/tests/grid/filtered_iterator_05.output
@@ -0,0 +1,2 @@
+
+DEAL::OK
-- 
2.39.5