Last modified: 2011-06-25 23:15:26 UTC
In the URL, the user's eye combs back and forth trying to figure out what the difference to the second highlighted item is. You highlighted it, now show the user the difference. If there is no difference, don't highlight it. (But there is, so say what it is right there!) If there is a whitespace difference only, then note that on the side, or with a "W" which the user can mouseover to reveal a message "whitespace changes only".
*** This bug has been marked as a duplicate of bug 13809 ***