IE: empty margins not visible in page with header X-UA-Compatible overwriting compatibility mode

[Jakub Ś]

1. Go to IE -> Tools -> Compatibility mode settings and add IP which you want to use to display HTML page E.g. 192.168.1.123
2. Place page attached to this ticket in samples folder. This page contains header

<meta http-equiv="X-UA-Compatible" content="IE=8" /> which should overwrite compatibility mode.

3. type "test" in editor, press enter 5 times and type "test2"
4. Switch to Source and back to WYSIWYG

Result: You will notice that there is no empty paragraphs between "test" and "test2"

I have managed to reproduce it in IE8 and IE9 and only when content attribute was set to IE8 - content="IE=8"

[Piotrek Koszuliński]

DUP of #8164.