Emoticon breaks if set as image again after double clicking the emotion

[hengly]

1.Run the test case,the test case based a custom build

2.Insert an emoticon

3.Double click the emoticon and set it as an image

Expected: Nothing should change, the emoticon should stay the same.

Actual: The image breaks.

Note:I found the dialog of ​http://demos.dojotoolkit.org/demos/editor/ will should an invalid url of the emoticon.However,If I change the dojo package name,the invalid message will not display

[bill]

Dup of #13460 (which has test case attached, so closing this ticket instead).