Index: _source/plugins/wysiwygarea/plugin.js
===================================================================
--- _source/plugins/wysiwygarea/plugin.js	(revision 6142)
+++ _source/plugins/wysiwygarea/plugin.js	(revision )
@@ -1000,29 +1000,34 @@
 			// Switch on design mode for a short while and close it after then.
 			function blinkCursor( retry )
 			{
+				// Avoid toggling design mode in an event thread,
+				// which will cause host page scrolling.(#6473)
+				setTimeout( function ()
+				 {
-				CKEDITOR.tools.tryThese(
-					function()
-					{
-						editor.document.$.designMode = 'on';
-						setTimeout( function()
-						{
-							editor.document.$.designMode = 'off';
-							if ( CKEDITOR.currentInstance == editor )
-								editor.document.getBody().focus();
-						}, 50 );
-					},
-					function()
-					{
-						// The above call is known to fail when parent DOM
-						// tree layout changes may break design mode. (#5782)
-						// Refresh the 'contentEditable' is a cue to this.
-						editor.document.$.designMode = 'off';
-						var body = editor.document.getBody();
-						body.setAttribute( 'contentEditable', false );
-						body.setAttribute( 'contentEditable', true );
-						// Try it again once..
-						!retry && blinkCursor( 1 );
-					});
+					 CKEDITOR.tools.tryThese(
+						 function()
+						 {
+							 editor.document.$.designMode = 'on';
+							 setTimeout( function()
+							 {
+								 editor.document.$.designMode = 'off';
+								 if ( CKEDITOR.currentInstance == editor )
+									 editor.document.getBody().focus();
+							 }, 50 );
+						 },
+						 function()
+						 {
+							 // The above call is known to fail when parent DOM
+							 // tree layout changes may break design mode. (#5782)
+							 // Refresh the 'contentEditable' is a cue to this.
+							 editor.document.$.designMode = 'off';
+							 var body = editor.document.getBody();
+							 body.setAttribute( 'contentEditable', false );
+							 body.setAttribute( 'contentEditable', true );
+							 // Try it again once..
+							 !retry && blinkCursor( 1 );
+						 });
+				 }, 0 );
 			}
 
 			// Create an invisible element to grab focus.