applyDefaults now respects null - if you want to override a property with applyDefaults, set it to undefined first - applyDefaults also now correctly applies a custom toString method (closes #1063).

git-svn-id: http://svn.openlayers.org/trunk/openlayers@5280 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Util.js

@@ -489,20 +489,37 @@ OpenLayers.Util.upperCaseObject = function (object) {
 
 /** 
  * Function: applyDefaults
- * Takes a hashtable and copies any keys that don't exist from
- *     another hashtable, by analogy with OpenLayers.Util.extend() from
+ * Takes an object and copies any properties that don't exist from
+ *     another properties, by analogy with OpenLayers.Util.extend() from
  *     Prototype.js.
  * 
  * Parameters:
- * to - {Object}
- * from - {Object}
+ * to - {Object} The destination object.
+ * from - {Object} The source object.  Any properties of this object that
+ *     are undefined in the to object will be set on the to object.
+ *
+ * Returns:
+ * {Object} A reference to the to object.  Note that the to argument is modified
+ *     in place and returned by this function.
  */
 OpenLayers.Util.applyDefaults = function (to, from) {
     for (var key in from) {
-        if (to[key] == null) {
+        if (to[key] === undefined ||
+            (from.hasOwnProperty
+             && from.hasOwnProperty(key) && !to.hasOwnProperty(key))) {
             to[key] = from[key];
         }
     }
+    /**
+     * IE doesn't include the toString property when iterating over an object's
+     * properties with the for(property in object) syntax.  Explicitly check if
+     * the source has its own toString property.
+     */
+    if(from.hasOwnProperty
+       && from.hasOwnProperty('toString') && !to.hasOwnProperty('toString')) {
+        to.toString = from.toString;
+    }
+    
     return to;
 };