Styles are not applied in Internet Explorer if backspace is the last key pressed

[Rick Schnorenberg]

Steps to Reproduce

1. Open the example document in the nightly test page ​http://nightly.ckeditor.com/14-04-03-06-05/standard/samples/replacebyclass.html
2. Place your cursor in some text that is not styled, for example the end of surface in "lunar surface"
3. Use the backspace key to delete the words "lunar surface"
4. Hit Ctrl+B to enable bold
5. Type the word "moon"

Expected result

...to step onto the moon...

Actual result

...to step onto the moon...

This happens with bold, italic, and underline and occurs with both the keyboard shortcuts and the toolbar buttons. It also occurs if you use multiple backspace presses or highlight the text you want to remove and press backspace once.

Browser

I can reproduce this on Internet Explorer 9, 10, and 11, it does occur on Internet Explorer 8 or Chrome/Firefox

[Jakub Ś]

Problem can be reproduced in IE9-11 from CKEditor 4.0 beta (works fine in CKE 3.x).