Element style trashing in IE7 due to case change

[Dinu]

In IE7, the styles are on a upper-lower-case carousel...

To reproduce (IE7):

• Insert smiley
  
• Image properties -> add style "background:url (UPPERCASE)"
  
• Image properties again -> style is changed to "BACKGROUND: url(UPPERCASE)" (not wrong yet, but still inconsistent)
  
• Switch to source view; style is now "background:url('''uppercase)" (this is wrong)
  

If there were a <div> with a set background with uppercase characters, it would be trashed as a result of:

• the operations above
• directly when replacing <textarea>

[Dinu]

Found to be also present in IE8, seemed it worked but it doesnt.
New test case:

<div id="container"><div style="background:url(someUppercaseUrl)"></div></div>

ckeditor() on container, then destroy(), someUppercaseUrl should preserve case (doesnt happen now)

FF, Opera and Safari seem unaffected

[Garry Yao]

Indeed a serious bug, affects all IE versions though.

[Dinu]

Looking at the patch, that was not my point:
The problem is that
url(someUppercasedUrl)
gets converted to
url(someuppercasedurl)

The choice of style case is purely cosmetic (url vs URL), although it would be nice to preserve the one users input. However, urls ARE case-insensitive, they should be preserved exactly. After some research, case-sensitive components should be:

• style:font-family (aliased style:font)
• style:background-image (aliased style:background)
• style:list-style-image (aliased style:list-style)

(as per ​http://www.w3schools.com/css/css_reference.asp)

[Alfonso Martínez de Lizarrondo]

dup of #5930