From 8be0cfc3caabaac3a48b9202eabefcfaced4647d Mon Sep 17 00:00:00 2001
From: Frederik Ramm <frederik@remote.org>
Date: Fri, 20 Apr 2012 07:04:27 +0000
Subject: [PATCH] avoid building invalid geometries

---
 build_geometry.cpp | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/build_geometry.cpp b/build_geometry.cpp
index 832b86dad..765c79bb1 100644
--- a/build_geometry.cpp
+++ b/build_geometry.cpp
@@ -475,20 +475,26 @@ size_t build_geometry(osmid_t osm_id, struct osmNode **xnodes, int *xcount, int
             if ((toplevelpolygons > 1) && enable_multi)
             {
                 std::auto_ptr<MultiPolygon> multipoly(gf.createMultiPolygon(polygons.release()));
-                std::string text = writer.write(multipoly.get());
-                wkts.push_back(text);
-                areas.push_back(multipoly->getArea());
-                wkt_size++;
+                if (multipoly->isValid())
+                {
+                    std::string text = writer.write(multipoly.get());
+                    wkts.push_back(text);
+                    areas.push_back(multipoly->getArea());
+                    wkt_size++;
+                }
             }
             else
             {
                 for(unsigned i=0; i<toplevelpolygons; i++) 
                 {
                     Polygon* poly = dynamic_cast<Polygon*>(polygons->at(i));;
-                    std::string text = writer.write(poly);
-                    wkts.push_back(text);
-                    areas.push_back(poly->getArea());
-                    wkt_size++;
+                    if (poly->isValid())
+                    {
+                        std::string text = writer.write(poly);
+                        wkts.push_back(text);
+                        areas.push_back(poly->getArea());
+                        wkt_size++;
+                    }
                     delete(poly);
                 }
             }