resetDirty after setData causes JavaScript error in IE8

[dpckuser]

In IE8 if I call resetDirty directly after setData, a JavaScript error is generated. The error text says: Error: 'this.$.innerHTML' is null or not an object.

Steps: 1) Load the attached test page in IE8. (This simply calls "setData" immediately followed by "resetDirty".) 2) Press the "setData and resetDirty" button.

Browser and OS: IE 8.0.6001.18702 Update Versions: 0 Windows XP Professional SP3

Screenshot(s): Attached

Test case file: Attached

Other: I have found that this happens when getFrameDocument in core/dom/element.js returns when "$.contentWindow.document.body" is still undefined.

[dpckuser]

Screenshot of resetDirty issue

[dpckuser]

Sample HTML file producing the resetDirty issue

[Alfonso Martínez de Lizarrondo]

setData is an asynchronous operation and the editor might not be ready right after calling it. Check the docs ​http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.editor.html#setData