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diff --git a/boost/geometry/algorithms/detail/envelope/areal.hpp b/boost/geometry/algorithms/detail/envelope/areal.hpp
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+++ b/boost/geometry/algorithms/detail/envelope/areal.hpp
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+// Boost.Geometry
+
+// Copyright (c) 2018 Oracle and/or its affiliates.
+
+// Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
+
+// Use, modification and distribution is subject to the Boost Software License,
+// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_ENVELOPE_AREAL_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_ENVELOPE_AREAL_HPP
+
+#include <boost/geometry/core/cs.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/iterators/segment_iterator.hpp>
+
+#include <boost/geometry/algorithms/detail/envelope/range.hpp>
+#include <boost/geometry/algorithms/detail/envelope/linear.hpp>
+
+#include <boost/geometry/algorithms/dispatch/envelope.hpp>
+
+namespace boost { namespace geometry
+{
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail { namespace envelope
+{
+
+template <typename EnvelopePolicy>
+struct envelope_polygon
+{
+    template <typename Polygon, typename Box, typename Strategy>
+    static inline void apply(Polygon const& polygon, Box& mbr, Strategy const& strategy)
+    {
+        typename ring_return_type<Polygon const>::type ext_ring
+            = exterior_ring(polygon);
+
+        if (geometry::is_empty(ext_ring))
+        {
+            // if the exterior ring is empty, consider the interior rings
+            envelope_multi_range
+                <
+                    EnvelopePolicy
+                >::apply(interior_rings(polygon), mbr, strategy);
+        }
+        else
+        {
+            // otherwise, consider only the exterior ring
+            EnvelopePolicy::apply(ext_ring, mbr, strategy);
+        }
+    }
+};
+
+
+}} // namespace detail::envelope
+#endif // DOXYGEN_NO_DETAIL
+
+#ifndef DOXYGEN_NO_DISPATCH
+namespace dispatch
+{
+
+
+template <typename Ring, typename CS_Tag>
+struct envelope<Ring, ring_tag, CS_Tag>
+    : detail::envelope::envelope_range
+{};
+
+template <typename Ring>
+struct envelope<Ring, ring_tag, spherical_equatorial_tag>
+    : detail::envelope::envelope_linestring_or_ring_on_spheroid
+{};
+
+template <typename Ring>
+struct envelope<Ring, ring_tag, geographic_tag>
+    : detail::envelope::envelope_linestring_or_ring_on_spheroid
+{};
+
+
+template <typename Polygon, typename CS_Tag>
+struct envelope<Polygon, polygon_tag, CS_Tag>
+    : detail::envelope::envelope_polygon
+        <
+            detail::envelope::envelope_range
+        >
+{};
+
+template <typename Polygon>
+struct envelope<Polygon, polygon_tag, spherical_equatorial_tag>
+    : detail::envelope::envelope_polygon
+        <
+            detail::envelope::envelope_linestring_or_ring_on_spheroid
+        >
+{};
+
+template <typename Polygon>
+struct envelope<Polygon, polygon_tag, geographic_tag>
+    : detail::envelope::envelope_polygon
+        <
+            detail::envelope::envelope_linestring_or_ring_on_spheroid
+        >
+{};
+
+
+template <typename MultiPolygon, typename CS_Tag>
+struct envelope<MultiPolygon, multi_polygon_tag, CS_Tag>
+    : detail::envelope::envelope_multi_range
+        <
+            detail::envelope::envelope_polygon
+              <
+                  detail::envelope::envelope_range
+              >
+        >
+{};
+
+template <typename MultiPolygon>
+struct envelope<MultiPolygon, multi_polygon_tag, spherical_equatorial_tag>
+    : detail::envelope::envelope_multi_range
+        <
+            detail::envelope::envelope_polygon
+              <
+                  detail::envelope::envelope_linestring_or_ring_on_spheroid
+              >
+        >
+{};
+
+template <typename MultiPolygon>
+struct envelope<MultiPolygon, multi_polygon_tag, geographic_tag>
+    : detail::envelope::envelope_multi_range
+        <
+            detail::envelope::envelope_polygon
+              <
+                  detail::envelope::envelope_linestring_or_ring_on_spheroid
+              >
+        >
+{};
+
+
+} // namespace dispatch
+#endif // DOXYGEN_NO_DISPATCH
+
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_ENVELOPE_AREAL_HPP