An non-authenticated user navigates his/her website, reviewing the content of each page. Soon, the user encounters a page that he/she would like to edit. The user clicks the "log in" link, and is either: a) redirected back to the front page of the website or b) redirected to a specific page. The problem is that now the user must re-navigate the site back to the page he/she wishes to edit in order to begin the editing process.
The solution to the problem stated above is to return the user back to the page he/she was viewing before attempting to "log in"
The Patch (against 6.x-1.2)
In order to preserve the current functionality of pubcookie, the patch only works if the "Successful login URL:" setting is empty. So if the administrator has decided that he wants users to be directed to a specific page after "log in" that will still happen. Otherwise, the user will be returned the page they were last viewing.