Dynamic loading comments load on top of page content

This is a beta feature; issues with it are not criticals.

Fixed in stable r14183 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/14183>.

It still loads over the content, but eventually settles down. It's possible it's just the layout engine reacting badly to the insanity.

I'm a bit disappointed the bug got closed with comments still loading on top of content, even if it just temporary :)
It makes the whole process feel clunky and generally indicates the added nodes aren't properly contained, opening up the door for breakage in future CSS/HTML changes.

Whats a good way to debug that?

The best way to debug it is using firebug.
I can't easily debug the javascript without getting the whole launchpad tree, but I'd bet this due to the height not being pre-calculated properly, YUI has some conveniences for this in its anim module.

Going a bit on a tangent here, you should never really have this many (html) nodes on a page. The CPU and ram usage during the loading and later scrolling of this page is a testament to that (also, the returned HTML is super noisy adding even more nodes like a table for each row).
In order to load huge amount of data on a page, what you need to do is have a fixed set of nodes that get re-written as you scroll (this is a big change from what you have designed right now, where a huge chunk of HTML is returned and appended).
We're working on something like this right now in U1 using YUI3, so if there's interest in pursuing this, I'd be happy set up a call to spread some of this knowledge around.

Here's a nice jquery example of the above concept in action: http://jsfiddle.net/SDa2B/

It should be noted that the bug being closed doesn't actually mean that I considered the bug fixed. I had a massive amount of trouble reproducing it with anything like the the reliability that Martin has managed. I didn't even see the bug at all when using Chrom(e|ium).

If this is going to be tackled properly we need to work at a deeper level than fixing the JS or indeed the returned HTML. There are lots of issues with the underlying model of bug comments (which have Special Things done to them at the View level), mostly to do with legacy behaviour but also connected to the activity log interleaving code. I shan't enumerate the problems that led me to use the rather kludgy solution that I did for dynamic comment loading, but I think we should go and fix that and only then come back to make the JS work better, otherwise we're just polishing the proverbially unpolishable.

I'm re-marking this triaged and removing myself as an assignee; the bug is definitely there, but it's not something we can tackle properly right now.

It has been released with a regression, that makes this critical now.

This was an issue in the old Firefox rendering engine. I cannot reproduce this using the current browser.