IE: Image dialog is unable to load image properties inside of a floating element

[wwalc]

1. Load the following source in IE:

   <div style="float: right">
   Foo <img alt="" src="http://a.cksource.com/c/1/inc/img/demo-little-red.jpg" /> Bar</div>
   

2. Select an image
3. Click "Image" button (do not use the context menu)
4. Image dialog opens, but all fields are empty.

It looks like it started happening in 3.2.1.

[wwalc]

Caused by [5214].

[wwalc]

Related issue: #7973 (caused by the same changeset)

[garry.yao]

The idea is that IE has separated focus management for different editing host (image and the floated div were different editing host), while editor::focus will always move focus to the editing document, thus in such case destroying the focus which was originally on the image element.

In order to avoid this, regularly query to the focus manager of the activate state of editor before moving the focus would be enough.