Deleting a widget with the keyboard removes the whole body

[transporthummel]

Bug

Since CKEditor version 4.16.1, deleting a widget using the keyboard (BACKSPACE or DELETE) can lead to the whole document body element being removed. Unsurprisingly, the editor isn't usable anymore after that.

For reproduction purposes, the JSFiddle sample below adds a very simple widget consisting of just one img tag. Just place the cursor behind the "deleteme" text and then delete the text and the image using BACKSPACE. When CKEditor determines the next element to apply the "fake selection" to, the outcome will be the body, which will then be removed.
According to my own investigation, this was probably caused by the fix done in #1572.

The error is still there in the latest version. In 4.16.0 it still works fine.

http://jsfiddle.net/transporthummel/xnm3sebc/5/

Expected result

The widget is selected by the fake selection and then removed.

Actual result

Instead of selecting the widget, the document body is removed, making the editor unusable.

[Comandeer]

I can confirm the issue. It seems that your investigation was right, the commit 1152d32 appears to be the culprit.

[CKEditorBot]

Closed in #5170