From 2ebc729cc822e7a2eb6ae983cf4d9ce3b8a43bf7 Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Fri, 10 Apr 2015 14:13:08 +0200
Subject: [PATCH] Clipper - fix PolyTree traversal

---
 benchmark/test_polygon_clipping.cpp | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/benchmark/test_polygon_clipping.cpp b/benchmark/test_polygon_clipping.cpp
index ff6878e45..2fd11fea5 100644
--- a/benchmark/test_polygon_clipping.cpp
+++ b/benchmark/test_polygon_clipping.cpp
@@ -512,26 +512,25 @@ public:
         bool first = true;
         while (polynode)
         {
-            //do stuff with polynode here
-            if (first) first = false;
-            else mp.emplace_back();
             if (!polynode->IsHole())
             {
+                if (first) first = false;
+                else mp.emplace_back(); // start new polygon
                 for (auto const& pt : polynode->Contour)
                 {
                     mp.back().exterior_ring.add_coord(pt.X, pt.Y);
                 }
-            }
-            else
-            {
-                mapnik::geometry::linear_ring hole;
-                for (auto const& pt : polynode->Contour)
+                // childrens are interior rings
+                for (auto const* ring : polynode->Childs)
                 {
-                    hole.add_coord(pt.X, pt.Y);
+                    mapnik::geometry::linear_ring hole;
+                    for (auto const& pt : ring->Contour)
+                    {
+                        hole.add_coord(pt.X, pt.Y);
+                    }
+                    mp.back().add_hole(std::move(hole));
                 }
-                mp.back().add_hole(std::move(hole));
             }
-            std::cerr << "Is hole? " << polynode->IsHole() << std::endl;
             polynode = polynode->GetNext();
         }
         std::string expect = expected_+".png";