From d9063db0a050ef7c85f2ab1527f9ca7120a10126 Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Tue, 21 Mar 2017 12:40:58 +0000
Subject: [PATCH] GeoJSON - make `geometry` element stricter and throw on
 invalid input.

---
 include/mapnik/json/create_geometry.hpp | 44 +++++++++++++++++--------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/include/mapnik/json/create_geometry.hpp b/include/mapnik/json/create_geometry.hpp
index 780a1d4cc..54270a848 100644
--- a/include/mapnik/json/create_geometry.hpp
+++ b/include/mapnik/json/create_geometry.hpp
@@ -44,7 +44,10 @@ struct create_point
     }
 
     template <typename T>
-    void operator()(T const&) const {} // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
     Geometry & geom_;
 };
 
@@ -56,21 +59,21 @@ struct create_linestring
 
     void operator() (ring const& points) const
     {
+        mapnik::geometry::line_string<double> line;
         std::size_t size = points.size();
-        if (size > 1)
+        line.reserve(size);
+        for (auto && pt : points)
         {
-            mapnik::geometry::line_string<double> line;
-            line.reserve(size);
-            for (auto && pt : points)
-            {
-                line.emplace_back(std::move(pt));
-            }
-            geom_ = std::move(line);
+            line.emplace_back(std::move(pt));
         }
+        geom_ = std::move(line);
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -107,7 +110,10 @@ struct create_polygon
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+       throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -131,7 +137,10 @@ struct create_multipoint
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -161,7 +170,10 @@ struct create_multilinestring
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -202,7 +214,10 @@ struct create_multipolygon
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -232,6 +247,7 @@ void create_geometry (Geometry & geom, int type, mapnik::json::positions const&
         util::apply_visitor(create_multipolygon<Geometry>(geom), coords);
         break;
     default:
+        throw std::runtime_error("Failed to parse geojson geometry");
         break;
     }
 }