XML Editor for Notifications writes corrupt HTML

Current Situation

• The Configuration view with the Notification tab allows to configure e-mail notification including a body in HTML format
• The default HTML is displayed similar to screen_01.png. The HTML source code starts e.g. with

  <style type="text/css">.tg \{border-collapse:collapse;border-spacing:0;border-color:#aaa;}
  

• If a user modifies the HTML then the XML Editor corrupts the HTML and the modified HTML looks as in screen_02.png. The style HTML element is stripped from the HTML source that now starts with:

  .tg {border-collapse:collapse;border-spacing:0;border-color:#aaa;}
  

• As a result the HTML is corrupt and cannot be displayed

Desired Behavior

• The XML Editor should not modify the HTML code added by a user and should not strip off HTML elements