addMenuGroup is not a function

[SLX]

I have this error "a.addMenuGroup is not a function" when I remove at once plugins contextmenu and scayt.

CKEDITOR.editorConfig = function( config )
  {
  config.removePlugins = 'contextmenu,scayt';
  }

Error is not triggered when I additionally remove liststyle.

Other people only disable plugin "scyte" to achieve this error. Look at this thread ​http://cksource.com/forums/viewtopic.php?f=11&t=18990

I think that is because plugins "liststyle" and "scyte" need required property with "menu" plugin.

I added this lines to source files and it seems to work:

File \ckeditor\_source\plugins\liststyle\plugin.js:10

(function()
{
	CKEDITOR.plugins.liststyle =
	{
  	requires : [ 'menu' ],               // HERE 
		init : function( editor )
		{

And in file \ckeditor\_source\plugins\scayt\plugin.js:486

	CKEDITOR.plugins.add( 'scayt',
	{
		requires : [ 'menubutton', 'menu' ],       //HERE

		beforeInit : function( editor )

[Frederico Caldeira Knabben]

DUP of #5799