enforce valid hsla values - refs #1954

include/mapnik/image_filter_types.hpp

@@ -26,13 +26,17 @@
 // mapnik
 #include <mapnik/config.hpp>
 #include <mapnik/color.hpp>
+#include <mapnik/config_error.hpp>
+
 // boost
 #include <boost/variant.hpp>
+
 // stl
 #include <vector>
 #include <ostream>
 #include <iterator>  // for std::back_insert_iterator
 
+
 namespace mapnik { namespace filter {
 
 struct blur {};
@@ -66,7 +70,15 @@ struct scale_hsla
       l0(_l0),
       l1(_l1),
       a0(_a0),
-      a1(_a1) {}
+      a1(_a1) {
+          if (h0 < 0 || h1 > 1 ||
+              s0 < 0 || s1 > 1 ||
+              l0 < 0 || l1 > 1 ||
+              a0 < 0 || a1 > 1)
+          {
+              throw config_error("scale-hsla values must be between 0 and 1");
+          }
+      }
     inline bool is_identity() const {
         return (h0 == 0 &&
                 h1 == 1 &&

tests/data/broken_maps/invalid-scale-hsla-filter.xml

@@ -0,0 +1,4 @@
+<Map>
+    <Style name="style" image-filters="scale-hsla(-1,1.1,0,1,0,1,0,1)">
+    </Style>
+</Map>