Fix area feature emitting during World generation.

generator/feature_merger.hpp

@@ -11,10 +11,13 @@ public:
   /// but only if they have common point
   void AppendFeature(FeatureBuilder1Merger const & fb);
 
-  void SetAreaSafe()
+  bool SetAreaSafe()
   {
-    if (!m_bArea)
-      m_bArea = true;
+    if (m_Geometry.size() < 3)
+      return false;
+
+    m_bArea = true;
+    return true;
   }
 
   uint32_t KeyType() const

generator/world_map_generator.hpp

@@ -40,9 +40,11 @@ private:
   {
     if (fbm.FirstPoint() == fbm.LastPoint())
     {
-      fbm.SetAreaSafe();
-      (*m_worldBucket)(fbm);
-      ++m_areasCounter;
+      if (fbm.SetAreaSafe())
+      {
+        (*m_worldBucket)(fbm);
+        ++m_areasCounter;
+      }
       return true;
     }
     else return false;