fix remove() function and add test

git-svn-id: http://svn.openlayers.org/trunk/openlayers@871 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Events.js

@@ -111,7 +111,7 @@ OpenLayers.Events.prototype = {
     
     /**
      * @param {String} type
-     * @param {Object} obj
+     * @param {Object} obj If none specified, defaults to this.object
      * @param {Function} func
      */
     unregister: function (type, obj, func) {
@@ -127,11 +127,15 @@ OpenLayers.Events.prototype = {
         }
     },
 
-    /**
+    /** Remove all listeners for a given event type. If type is not registered,
+     *   does nothing.
+     * 
      * @param {String} type
      */
     remove: function(type) {
-        this.listeners[type].pop();
+        if (this.listeners[type] != null) {
+            this.listeners[type] = new Array();
+        }
     },
 
     /** Trigger a specified registered event