558409 - Smooth scrolling is choppy when tiled background is present

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Albo P. Fossa]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3

This does not occur in other browsers (e.g., Webkit, Safari, Opera, Chrome). It is not quite as obvious in Camino, so it may be Gecko-related? It is not also not quite as obvious, but still occurs to some extent, with a solid (i.e., non-tiled) background. And only at the cited URL (Twitter). It has occurred with previous releases of Firefox, Minefield, MacOSX.

The laptop I'm using is a MacBookPro. The manner in which I'm scrolling is via trackpad: two-finger swipe. In all other browsers, and in all other websites with Firefox, the scroll is smooth and pixel-perfect. In Twitter, with a tiled background present, scrolling is noticeably "jerky" - spasmodic, visually erratic, non-smooth, interrupted by small pauses of micro-second duration.

Reproducible: Always

Steps to Reproduce:
[All with a MacBookPro, Firefox with Smooth Scrolling set in Preferences]
1. Go to Twitter
2. Go to Settings
3. Choose Design
4. Change Background Image
5. Load an image and check "tile background"
6. Save changes
7. Return to Twitter home page
8. Try scrolling using trackpad
Actual Results:  
jerky, spasmodic scrolling

Expected Results:  
smooth scrolling

For "actual results" versus "expected results" compare the Firefox scrolling to (for example) Webkit or Safari scrolling with the same Twitter userid

Comment 1

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 3.6.13 or later in safe mode? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles

You can also try to reproduce in Firefox 4 Beta 8 or later, there are many improvements in the new version, http://www.mozilla.com/en-US/firefox/all-beta.html