apply fix from #2418 to 2.3.x branch

include/mapnik/agg_renderer.hpp

@@ -127,6 +127,8 @@ public:
     }
 
     void painted(bool painted);
+    bool painted();
+
     inline eAttributeCollectionPolicy attribute_collection_policy() const
     {
         return DEFAULT;

include/mapnik/cairo_renderer.hpp

@@ -115,6 +115,12 @@ public:
         // cairo renderer doesn't support processing of multiple symbolizers.
         return false;
     }
+
+    bool painted()
+    {
+        return true;
+    }
+
     void painted(bool /*painted*/)
     {
         // nothing to do

include/mapnik/feature_style_processor_impl.hpp

@@ -704,7 +704,7 @@ void feature_style_processor<Processor>::render_style(
             }
         }
     }
-    p.painted(was_painted);
+    p.painted(p.painted() | was_painted);
     p.end_style_processing(*style);
 }
 

include/mapnik/grid/grid_renderer.hpp

@@ -114,14 +114,22 @@ public:
         // grid renderer doesn't support processing of multiple symbolizers.
         return false;
     }
+
+    bool painted()
+    {
+        pixmap_.painted();
+    }
+
     void painted(bool painted)
     {
         pixmap_.painted(painted);
     }
+
     inline eAttributeCollectionPolicy attribute_collection_policy() const
     {
         return DEFAULT;
     }
+
     inline double scale_factor() const
     {
         return scale_factor_;

src/agg/agg_renderer.cpp

@@ -457,6 +457,12 @@ void agg_renderer<T>::painted(bool painted)
     pixmap_.painted(painted);
 }
 
+template <typename T>
+bool agg_renderer<T>::painted()
+{
+    return pixmap_.painted();
+}
+
 template <typename T>
 void agg_renderer<T>::debug_draw_box(box2d<double> const& box,
                                      double x, double y, double angle)