protect for null bounds (not-loaded map)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@993 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer.js

@@ -170,8 +170,11 @@ OpenLayers.Layer.prototype = {
     setVisibility: function(visible) {
         this.div.style.display = (visible) ? "block" : "none";
         if ((visible) && (this.map != null)) {
+            var extent = this.map.getExtent();
+            if (extent != null) {
                 this.moveTo(this.map.getExtent());
             }
+        }
     },
     
     

lib/OpenLayers/Layer/Grid.js

@@ -135,6 +135,10 @@ OpenLayers.Layer.Grid.prototype =
      * @param {Boolean} minor
      */
     moveTo:function(bounds, zoomChanged, minor) {
+        if (bounds == null) {
+            bounds = this.map.getBounds();
+        }
+        if (bounds != null) {
             if (!this.getVisibility()) {
                 if (zoomChanged) {
                     //now clear out the old grid and start a new one
@@ -160,6 +164,7 @@ OpenLayers.Layer.Grid.prototype =
                     }
                 }
             }
+        }
     },
     
     /**