easyui 1.4.2 bug messager

Code:

// I open a progress messager by 
$.messager.progress();

// and close it by 
$.messager.progress('close');

error got in console:
Uncaught TypeError: Cannot read property 'onClose' of undefined

I fixed it by making below changes in file jquery.easyui.min.js line 3924
from

Code:

if(_2ad.onClose){
_2ad.onClose.call(this);
}

to 

Code:

if(_2ad && _2ad.onClose){
_2ad.onClose.call(this);
}

// perhaps better
if(opts.onClose){
opts.onClose.call(this);
}

OR

an object type param must be passed in  when calling  $.messager.progress() even if a blank one.

Code:

$.messager.progress({});