URL is applied incorrectly when the selection contains an anchor

[Teresa Monahan]

When we try to apply a new link to a selection that already contains an anchor, the url for the anchor does not get updated with the new url value.

To reproduce this issue:

1. Open any sample from the nightly build and enter the following in the source tab

   <p>
   	text goes here <a href="http://ckeditor.com">URL goes here</a> More text goes here</p>
   <p>
   

2. Switch back to wysiwyg mode and select all the text.
   
3. Click on the 'Link' icon and specify a url in the link dialog. Click OK.
   

Expected Result: The new URL value gets applied to the entire text including the anchor node.

Actual Result: The original anchor still has its old url value, while the new url value is applied to the text before and after it.

[Jakub Ś]

Reproducible in all browsers from CKEditor 3.0.

[Piotrek Koszuliński]

See also #8368 where an additional case with an empty <strong> is mentioned.