I think what my problem is, and it's related to this or maybe what ZeXrO meant.
Suppose there's a thread with 14 posts (and the page cutoff is 15) and I read them all. While I'm away, 2 posts are made -- one on page 1 and one on page 2. When I do the "
new posts" search, I see 2 pages. If I click page 2, then the new post on page 1 is marked as read. If I go to page 1, I won't notice it as new.
Possible solutions:
* Hard: preserve unread-ness on a per-post basis and only clear it on viewing the post rather than anything in the thread.
* Easy: the search page marks the page with the first new post. I can assume that all posts starting from there will be new, and I won't run the risk of missing anything.
The easy solution won't permanently mark posts as new for each page you look at, but hopefully you can figure out what's new if you know where it starts.
Am I on the right track? It's late and I'm not entirely coherent right now.