Index: _source/tests/core/editor_multipleClasses.html
===================================================================
--- _source/tests/core/editor_multipleClasses.html	(revision 0)
+++ _source/tests/core/editor_multipleClasses.html	(revision 0)
@@ -0,0 +1,88 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+	<title>Core : Editor</title>
+	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+	<link rel="stylesheet" type="text/css" href="../test.css" />
+	<script type="text/javascript" src="../../../ckeditor_source.js"></script>
+	<script type="text/javascript" src="../test.js"></script>
+	<script type="text/javascript">
+	//<![CDATA[
+	
+function prepareEditor( elementId, mode, config, callback, context )
+{
+	CKEDITOR.on( 'instanceReady',
+		function( evt )
+		{
+			var isMe = mode == CKEDITOR.ELEMENT_MODE_REPLACE ? 
+				evt.editor.name == elementId
+				: evt.editor.element.$ == 
+					document.getElementById( elementId );
+			if ( isMe )
+			{
+				callback.call( context, evt.editor );
+			}
+		}, this );
+
+	mode = mode || CKEDITOR.ELEMENT_MODE_REPLACE;
+	switch( mode )
+	{
+		case CKEDITOR.ELEMENT_MODE_REPLACE :
+			CKEDITOR.replace( elementId, config );
+			break;
+		case CKEDITOR.ELEMENT_MODE_APPENDTO :
+			CKEDITOR.appendTo( elementId, config );
+			break;
+	}
+}
+
+
+CKEDITOR.test.addTestCase( ( function()
+{
+	
+	// Local references.
+	var assert = CKEDITOR.test.assert,
+		arrayAssert = YAHOO.util.ArrayAssert;
+	
+	var doc = new CKEDITOR.dom.document( document );
+		
+	return {
+
+		/**
+		 * Make sure there's no multiple classes been attached on every elements.
+		 */
+		test_multipleClasses : function()
+		{
+			var multiClassesRegex = /\w+\s\w+/;
+			prepareEditor( 'editor1', null, null, function( editor )
+				{
+					this.resume( function()
+					{
+						var dirtyElements = [];
+						var walker = new CKEDITOR.dom.domWalker( doc.getById( 'editor1' ) );
+						walker.on( 'step', function( evt )
+						{
+							var node = evt.data.node;
+							// Catch all elements wth multiple classes.
+							if ( node && node.type == CKEDITOR.NODE_ELEMENT && 
+								multiClassesRegex.test ( node.$.className ) )
+								dirtyElements.push( node );
+						} );
+						walker.forward();
+						assert.isTrue( dirtyElements.length == 0, 'Elements are having multiple css classes.' );
+					} );
+				}, this );
+				this.wait();	        
+		},
+		
+		name : document.title
+	};
+})() );
+
+	//]]>
+	</script>
+</head>
+<body>
+	<textarea id="editor1"></textarea>
+</body>
+</html>
\ No newline at end of file
