Button.setToolTip(null) behaviour

[bogc]

In ExtJs 3.x calling setToolTip(null) would remove the previous tooltip attached to the button. In ExtJs 4 the tooltip displays the string null, and the empty string makes the tooltip disappear.

Is it normal? This occurs in 4.1.1 & 4.2 latest beta


null_tooltip.png

Ext.define('MyApp.view.MyPanel', {
  extend: 'Ext.panel.Panel',

  height: 250,
  width: 400,
  title: 'My Panel',

  initComponent: function() {
    var me = this;

    Ext.applyIf(me, {
      dockedItems: [
        {
          xtype: 'toolbar',
          dock: 'top',
          items: [
            {
              xtype: 'button',
              text: 'Button with null tooltip - click on me',
              tooltip: 'I have a tooltip',
              listeners: {
                click: {
                  fn: me.onButtonClick,
                  scope: me
                }
              }
            },
            {
              xtype: 'button',
              text: 'Button with empty string tooltip',
              tooltip: ''
            }
          ]
        }
      ]
    });

    me.callParent(arguments);
  },

  onButtonClick: function(button, e, options) {

    alert('setting the tooltip to null');
    button.setTooltip(null);
  }

});

Thanks