ExtJs 4 FormPanel进度条(Wait mask)灰色蒙版不能正常隐藏的BUG

Ext.define('Ext.form.SubmitFix', {
    override: 'Ext.ZIndexManager',
 
    register : function(comp) {
        var me = this,
            compAfterHide = comp.afterHide;
      
        if (comp.zIndexManager) {
            comp.zIndexManager.unregister(comp);
        }
        comp.zIndexManager = me;
 
        me.list[comp.id] = comp;
        me.zIndexStack.push(comp);
      
        // Hook into Component's afterHide processing
        comp.afterHide = function() {
            compAfterHide.apply(comp, arguments);
            me.onComponentHide(comp);
        };
    },
 
    /**
    * Unregisters a {@link Ext.Component} from this ZIndexManager. This should not
    * need to be called. Components are automatically unregistered upon destruction.
    * See {@link #register}.
    * @param {Ext.Component} comp The Component to unregister.
    */
    unregister : function(comp) {
        var me = this,
            list = me.list;
      
        delete comp.zIndexManager;
        if (list && list[comp.id]) {
            delete list[comp.id];
          
            // Relinquish control of Component's afterHide processing
            delete comp.afterHide;
            Ext.Array.remove(me.zIndexStack, comp);
 
            // Destruction requires that the topmost visible floater be activated. Same as hiding.
            me._activateLast();
        }
    }
});