Ticket #4397: 4397.patch

_source/plugins/wysiwygarea/plugin.js

@@ -353 +353 @@
                                                         body.removeAttribute( 'disabled' );
                                                 }
                                                 else
-                                                        domDocument.designMode = 'on';
+                                                        // Avoid opening design mode in a frame window thread,
+                                                        // which will cause host page scrolling.(#4397)
+                                                        setTimeout( function(){
+                                                                domDocument.$.designMode = 'on';
+                                                        }, 0 );
 
                                                 // IE, Opera and Safari may not support it and throw
                                                 // errors.