From a7485784ca403fbc4d6f2c0806df7ae4124f9f97 Mon Sep 17 00:00:00 2001
From: Adam Wulkiewicz <adam.wulkiewicz@gmail.com>
Date: Wed, 3 Nov 2021 15:29:19 +0100
Subject: [PATCH] [envelope] Reverse holes to avoid calculating mbr for the
 outside in spherical and geographic CS.

---
 .../algorithms/detail/envelope/areal.hpp      | 27 ++++++++++++++-----
 .../envelope_expand/envelope_on_spheroid.cpp  | 20 ++++++++++++++
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/envelope/areal.hpp b/include/boost/geometry/algorithms/detail/envelope/areal.hpp
index 81aa1c82c..ece4d3d14 100644
--- a/include/boost/geometry/algorithms/detail/envelope/areal.hpp
+++ b/include/boost/geometry/algorithms/detail/envelope/areal.hpp
@@ -22,6 +22,8 @@
 
 #include <boost/geometry/algorithms/dispatch/envelope.hpp>
 
+#include <boost/geometry/views/reversible_view.hpp>
+
 namespace boost { namespace geometry
 {
 
@@ -29,6 +31,24 @@ namespace boost { namespace geometry
 namespace detail { namespace envelope
 {
 
+
+struct envelope_hole
+{
+    template <typename Range, typename Box, typename Strategies>
+    static inline void apply(Range const& range, Box& mbr, Strategies const& strategies)
+    {
+        // Reverse holes to avoid calculating the envelope for the outside
+        // in spherical and geographic coordinate systems
+        detail::clockwise_view
+            <
+                Range const,
+                geometry::point_order<Range>::value == counterclockwise
+                    ? clockwise : counterclockwise
+            > view(range);
+        strategies.envelope(range, mbr).apply(view, mbr);
+    }
+};
+
 struct envelope_polygon
 {
     template <typename Polygon, typename Box, typename Strategy>
@@ -39,18 +59,13 @@ struct envelope_polygon
 
         if (geometry::is_empty(ext_ring))
         {
-            // TODO: In spherical and geographic this is ambiguous. A hole technically is a ring
-            // defining the outside so the envelope would cover more than half of the globe.
-            // So depending on what we want we could consider reversing holes before passing them
-            // below.
-
             // use dummy multi polygon to get the strategy because there is no multi ring concept
             using strategy_t = decltype(strategy.envelope(detail::dummy_multi_polygon(),
                                                           detail::dummy_box()));
             // if the exterior ring is empty, consider the interior rings
             envelope_multi_range
                 <
-                    envelope_range
+                    envelope_hole
                 >::template apply<strategy_t>(interior_rings(polygon), mbr, strategy);
         }
         else
diff --git a/test/algorithms/envelope_expand/envelope_on_spheroid.cpp b/test/algorithms/envelope_expand/envelope_on_spheroid.cpp
index 58fe132ab..e270fdba4 100644
--- a/test/algorithms/envelope_expand/envelope_on_spheroid.cpp
+++ b/test/algorithms/envelope_expand/envelope_on_spheroid.cpp
@@ -2710,20 +2710,40 @@ BOOST_AUTO_TEST_CASE( envelope_cw_ring )
 #endif
 
     // From disjoint  https://svn.boost.org/trac/boost/ticket/9162
+    // Polygons containing poles
     tester::apply("r22cw",
                   from_wkt<G>("POLYGON((0 80,-90 80,-180 80,90 80,0 80))"),
                   -180, 80, 180, 90);
     tester::apply("r23cw",
                   from_wkt<G>("POLYGON((0 -80,90 -80,-180 -80,-90 -80,0 -80))"),
                   -180, -90, 180, -80);
+    // Polygons greater than half of the globe
     tester::apply("r24cw",
                   from_wkt<G>("POLYGON((0 80,90 80,-180 80,-90 80,0 80))"),
                   -180, -90, 180, 82.892923889553458);
     tester::apply("r25cw",
                   from_wkt<G>("POLYGON((0 -80,-90 -80,-180 -80,90 -80,0 -80))"),
                   -180, -82.892923889553458, 180, 90);
+    // Normal test case
     tester::apply("r26cw",
                   from_wkt<G>("POLYGON((30 0,30 30,90 30, 90 0, 30 0))"),
                   30, 0, 90, 33.690067525979771);
+
+    // Invalid polygons with holes containing poles
+    tester::apply("r27cw",
+                  from_wkt<G>("POLYGON((),(0 80,90 80,-180 80,-90 80,0 80))"),
+                  -180, 80, 180, 90);
+    tester::apply("r28cw",
+                  from_wkt<G>("POLYGON((),(0 -80,-90 -80,-180 -80,90 -80,0 -80))"),
+                  -180, -90, 180, -80);
+
+    typedef bg::model::polygon<point_type, false> G2;
+    typedef test_envelope_on_sphere_or_spheroid<G2, B> tester2;
+    tester2::apply("r27ccw",
+                   from_wkt<G2>("POLYGON((),(0 80,-90 80,-180 80,90 80,0 80))"),
+                   -180, 80, 180, 90);
+    tester2::apply("r28ccw",
+                   from_wkt<G2>("POLYGON((),(0 -80,90 -80,-180 -80,-90 -80,0 -80))"),
+                   -180, -90, 180, -80);
 }