1045906 - thedailybeast.com progress bar animation is very jumpy

Status: RESOLVED DUPLICATE of bug 1048838

(Core :: Layout, defect)

Description

[Chris Peterson [:cpeterson]]

[Tracking Requested - why for this release]:

STR:
1. Load http://www.thedailybeast.com/articles/2014/05/29/renewables-can-make-fossil-fuel-more-efficient.html
2. Slowly scroll down the page.
3. Watch the "READ THIS.list" section on the right side of the page. As the page scrolls, a gray progress bar fills the "READ THIS.list" section.

RESULT:
In Firefox 33, the progress bar is very jumpy. In Firefox 32, it's smooth. I'm running OS X on a Retina/HiDPI MBP.

Comment 1

[Chris Peterson [:cpeterson]]

Brian, I bisected this regression in Nightly 33 build 2014-06-21 to this mozilla-inbound pushlog that only includes your fix for CommonElementAnimationData bug 1025709:

https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=e9118a2be9b3&tochange=2c21b94a7775

Comment 2

[Brian Birtles (:birtles)]

I can reproduce this on Windows 8 too. It definitely seems like I regressed this in bug 1025709 but I'm not sure yet how.

This might take a while to debug and I'm away on PTO after tomorrow. If anyone else is able to look into it in the meantime, please feel free!

Comment 3

[Markus Stange [:mstange]]

Attachment: testcase

Comment 4

[Sylvestre Ledru [:Sylvestre]]

Regression. Tracking

Comment 5

[David Baron :dbaron:]

Seems likely to be the same bug as 1048838, which has a little more analysis.

Comment 6

[David Baron :dbaron:]

Fixed by bug 1048838.