From f3a6cac99bffeae4a0f9343cc460a430d77ccdbb Mon Sep 17 00:00:00 2001
From: Denis Davydov <davydden@gmail.com>
Date: Sun, 4 Nov 2018 22:44:26 +0100
Subject: [PATCH] set components correctly in IncrementalFunction

---
 source/base/incremental_function.cc        |  3 +-
 tests/base/functions_incremental_03.cc     | 41 ++++++++++++++++++++++
 tests/base/functions_incremental_03.output |  2 ++
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 tests/base/functions_incremental_03.cc
 create mode 100644 tests/base/functions_incremental_03.output

diff --git a/source/base/incremental_function.cc b/source/base/incremental_function.cc
index 18091c358d..38739f9bd3 100644
--- a/source/base/incremental_function.cc
+++ b/source/base/incremental_function.cc
@@ -25,7 +25,8 @@ namespace Functions
   template <int dim, typename RangeNumberType>
   IncrementalFunction<dim, RangeNumberType>::IncrementalFunction(
     Function<dim, RangeNumberType> &base)
-    : base(base)
+    : Function<dim, RangeNumberType>(base.n_components)
+    , base(base)
     , delta_t(numbers::signaling_nan<time_type>())
     , values_old(base.n_components)
   {}
diff --git a/tests/base/functions_incremental_03.cc b/tests/base/functions_incremental_03.cc
new file mode 100644
index 0000000000..3284f106ee
--- /dev/null
+++ b/tests/base/functions_incremental_03.cc
@@ -0,0 +1,41 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2018 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.
+//
+// ---------------------------------------------------------------------
+
+
+// Check that IncrementalFunction use correct number of components
+
+#include <deal.II/base/incremental_function.h>
+
+#include "../tests.h"
+
+template <int dim>
+void
+check(const unsigned int n_comp = 3)
+{
+  Functions::ZeroFunction<dim>        func(n_comp);
+  Functions::IncrementalFunction<dim> inc(func);
+
+  AssertThrow(inc.n_components == n_comp, ExcInternalError());
+
+  deallog << "OK" << std::endl;
+}
+
+int
+main()
+{
+  initlog();
+
+  check<2>();
+}
diff --git a/tests/base/functions_incremental_03.output b/tests/base/functions_incremental_03.output
new file mode 100644
index 0000000000..0fd8fc12f0
--- /dev/null
+++ b/tests/base/functions_incremental_03.output
@@ -0,0 +1,2 @@
+
+DEAL::OK
-- 
2.39.5