376475 - Laggy scrolling on certain sites with window in front of Firefox

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Steve England [:stevee]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a4pre) Gecko/20070404 Minefield/3.0a4pre ID:2007040403 [cairo]

1. New profile, start firefox
2. Tools > Options > Advanced > General > Use Smooth Scrolling
3. Maximize your browser window
4. Visit http://www.neowin.net/
5. Get Windows Task Manager up. In it, choose Options > Always On Top and then place the Task Manager window squarely in the middle of the firefox window (any window in front of the firefox window will do, as long as you can make it Always On Top)
6. Now give focus back to firefox and use the mousewheel to scroll up and down the page

Expected:
- In the area above and below the Task Manager window, the website should scroll into view smoothly

Actual:
- In the area above and below the Task Manager window, the website lags into view whilst scrolling


No laggy scrolling when another window is infront of firefox on neowin.net
- Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a1) Gecko/20060222 Firefox/1.6a1 (Cairo not enabled)

Laggy scrolling when another window is infront of firefox on neowin.net
- Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a1) Gecko/20060223 Firefox/1.6a1 (Cairo enabled)

So caused by the landing of bug 323923.

I was hoping that cairo 1.4.2 would fix this problem, but apparently not.
The problem does not happen on the Firefox 2.0 branch.
Also, this problem doesn't happen on all pages, just some.

Comment 1

[Steve England [:stevee]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a7pre) Gecko/2007072411 Minefield/3.0a7pre ID:2007072411

Still present with latest build (Cairo 1.5.x) (bug 383960)

Comment 2

[Lucas Malor (mail: c6kfnkn2uc AT snkmail DOT c0m)]

It seems a duplicate of Bug 372039 or Bug 361754.

Comment 3

[Wayne Mery (:wsmwk)]

stevee do you still see this?

WFM Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/2009042316 Firefox/3.0.10 (.NET CLR 3.5.30729)

Comment 4

[Steve England [:stevee]]

I can't reproduce it anymore, but neowin.net had a redesign a while ago. I guess this bug can be closed since it doesn't contain any useful information.