IE11: span witch css-class turns into em-tag

[AndreasT]

Hi,

i have a problem with automatic replacing of Span-tags with em-Tags.

Online test: ​http://jsfiddle.net/zsfwshun/

Steps to reproduce

0. Only in IE11!! (IE10 not tested)
1. As you can see on JSFiddle the defined css-class is applied to my span and we see the "italic" formatting
2. Select the text with your mouse (not CTRL+A)
3. Start typing over the selected text
4. Click on Source-Mode button and the result is <em>Lorem Ipsum</em>

If JSFiddle is down:

1. Define your textarea as following:

<textarea id="editor1">

<p><span class="myItalic">Lorem Ipsum</span></p>

</textarea>

2. Init CKEditor:

CKEDITOR.addCss('.myItalic {font-style: italic;}'); CKEDITOR.replace( 'editor1', {

allowContent: true, extraAllowedContent : 'span(*)'

} );

Expected result

<p><span class="myItalic">My new Lorem Ipsum</span></p>

Span tags should not be replaced with em-Tags like in other Browsers (FF, Chrome, ...)

Google Chrome (46.0.2490.80) Mozilla Firefox (41)

Actual result

The output in Source-Mode is: <p><em>my new text</em></p>

Other details (browser, OS, CKEditor version, installed plugins)

CKEditor version: 4.5.4

Thank you in advance!