Recalculate scale factor in drawLegendIcon from mapscript (#5287)

Author: szekerest

mapscript/swiginc/class.i

@@ -176,7 +176,14 @@
     return (char *) msNextKeyFromHashTable(&(self->metadata), lastkey);
   }
 
-  int drawLegendIcon(mapObj *map, layerObj *layer, int width, int height, imageObj *dstImage, int dstX, int dstY) {
+  int drawLegendIcon(mapObj *map, layerObj *layer, int width, int height, imageObj *dstImage, int dstX, int dstY) {    
+    if(layer->sizeunits != MS_PIXELS) {
+      map->cellsize = msAdjustExtent(&(map->extent), map->width, map->height);
+      layer->scalefactor = (msInchesPerUnit(layer->sizeunits,0)/msInchesPerUnit(map->units,0)) / map->cellsize;
+    }
+    else
+      layer->scalefactor = map->resolution/map->defresolution;
+    
     return msDrawLegendIcon(map, layer, self, width, height, dstImage, dstX, dstY, MS_TRUE, NULL);
   }