It is complicated, because a user is on "article.php" and has filtering and sorting chosen, and when they add a comment they go to "add_comment.php" and so I have to pass all of that data to my other script. Not to mention, what if I have a "pretty URL" with no query-string like this...
Now I have to pass the default values to my "add_comment.php" script?!
You missed my point...
If a user is here...
...and they post a comment, but the "last page" is page 7, then where should I take them?
Presumably I would keep the same filtering and sorting, but instead of taking them literally back to where they were, I would take them to Page 7.
Well, during supper, this is the approach I came up with...
If you were in your Inbox (e.g. email or PM) and you had things sorted by Subject in ascending order, and you were on page 2 on Message #27, and then you clicked on the column heading to sort in descending order by Date, most UI's would take you back to the top of Page 1. (It is understood that if you re-sort, you lose your place!)
Well, thinking things over, I think the same should apply here!
Regardless of what filter or sort you have chosen, or what page you are on, if you add a new Comment, then I think it is quite sufficient to set Filter=None, Sort=Date, Order=Asc and take you to the last page so you can see your new Comment.
First off, you won't be "Editor's Choice" or "Most Popular" in the few seconds from your post, so Filtering is out the window.
And if you had Comments sorted by "Rating" or even "Date", then get over it.
Things sorted in the default way - which is oldest Comment 1st, and newest Comment last - and having my code take you to whatever is the last page and to the bottom of it so you can see your new Comment is more than enough!
I think I am saying something similar to what you said above, but I disagree that if I left everything the way it was and tried to take the user back to the same Filter, Sort, Order, Page that it would be easy going between two scripts! (Doable? Yes. Easy? No! Going to happen? Nope!)