Steps to reproduce:
1.Go to this page:http://en.wikipedia.beta.wmflabs.org/wiki/12thmayff?veaction=edit
2.Select the first image on the page: Dau_ho_thoi_Ho.png
3.Make any edit on the image's caption field
4.Click on "Apply Changes"
The Media Settings dialog does not get closed , the edit does not get saved
The following error appears in the console:
TypeError: originalDimensions is undefined