modifier+click no longer opens a new tab on FF when using externalGraphic. r=bartvde,pgiraud (closes #1421)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11584 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Renderer/SVG.js

@@ -285,6 +285,7 @@ OpenLayers.Renderer.SVG = OpenLayers.Class(OpenLayers.Renderer.Elements, {
                 node.setAttributeNS(null, "height", height);
                 node.setAttributeNS(this.xlinkns, "href", style.externalGraphic);
                 node.setAttributeNS(null, "style", "opacity: "+opacity);
+                node.onclick = OpenLayers.Renderer.SVG.preventDefault;
             } else if (this.isComplexSymbol(style.graphicName)) {
                 // the symbol viewBox is three times as large as the symbol
                 var offset = style.pointRadius * 3;
@@ -983,3 +984,12 @@ OpenLayers.Renderer.SVG.LABEL_VSHIFT = {
     "t": "-70%",
     "b": "0"    
 };
+
+/**
+ * Function: OpenLayers.Renderer.SVG.preventDefault
+ * Used to prevent default events (especially opening images in a new tab on
+ * ctrl-click) from being executed for externalGraphic symbols
+ */
+OpenLayers.Renderer.SVG.preventDefault = function(e) {
+    e.preventDefault && e.preventDefault();
+};