Index: /CKEditor/tests/tt/4880/1.html
===================================================================
--- /CKEditor/tests/tt/4880/1.html	(revision 6481)
+++ /CKEditor/tests/tt/4880/1.html	(revision 6481)
@@ -0,0 +1,66 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
+	"http://www.w3.org/TR/html4/loose.dtd">
+<html>
+<head>
+	<title>Ticket: #4880 No change to html comment</title>
+	<meta name="tags" content="editor,unit,all">
+	<script type="text/javascript" src="../../cktester/cell.js"></script>
+	<script>
+( function()
+{
+	var ts, tc, assert = CKEDITOR.test.assert, test = CKEDITOR.test, selector = YAHOO.util.Selector;
+
+	YAHOO.tool.TestRunner.add( ts = new CKEDITOR.test.suites.editorTestSuite(
+		{
+				editorName : 'test_editor_1',
+				
+				name :document.title
+		} ) );
+
+	ts.add( tc = new YAHOO.tool.TestCase(
+	{
+		setUp : function ()
+		{
+			// Force result data un-formatted.
+			ts.editor.dataProcessor.writer._.rules = {};
+			ts.editor.focus();
+		},
+
+		test_no_changes: function()
+		{
+			var editor = ts.editor,
+				output = '<style type="text/css"><!--.bloco1_titulo { font-family:Verdana, Arial, Helvetica, sans-serif; font-size:10px; color:#FFFFFF; font-weight:bold; background-color:#333366; padding-left:10px; }--></style>',
+			    contentWithSelection = test.getValueAsHtml( 'input_1' );
+			
+			test.setHtmlWithSelection( editor.document.getBody(), contentWithSelection );
+						
+			this.wait(function() 
+			{
+				//Switch between modes
+				editor.execCommand( 'source' );
+				//to wysiwyg
+				this.wait(function() 
+				{
+					editor.execCommand( 'source' );
+					//Verify content
+					this.wait(function() 
+					{
+						assert.areSame( output, editor.getData() );
+					}, 1000);
+				}, 1000);
+			}, 1000 );
+		}	
+	} ) );
+} )();
+	</script>
+</head>
+<body>
+<textarea id='input_1'>
+<style type="text/css">
+<!--
+.bloco1_titulo { font-family:Verdana, Arial, Helvetica, sans-serif; font-size:10px; color:#FFFFFF; font-weight:bold; background-color:#333366; padding-left:10px; }
+-->
+</style>
+</textarea>
+</body>
+</html>
