480806 - Scrolling is very slow When the page is made a full zoom.

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Alice0775 White]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b3pre) Gecko/20090228 Firefox/3.1b3pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090228 Minefield/3.2a1pre

If you full zoom, then use scroll on the mouse or middle click to scroll,
Scrolling is slow.

Reproducible: Always

Steps to Reproduce:
1.Start Minefield with new profile.
2.Open URL, and  wait completion of loading the page.
3.zoom in (ctrl +) (ctrl +) (ctrl +)
4.scroll (mouse scroll, or arrow keys)

Actual Results:  
Scrolling is slow.

Expected Results:  
Scrolling is smooth.

With out FullZoom (reset zoom), the scrolling is smooth.


Regression range
Works fine: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20081202 Minefield/3.2a1pre

Broken: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20081203 Minefield/3.2a1pre

Similar Bugs are as follows.
  Bug 425234 -  Full page zoom very slow on ajaxian.com  
  Bug 404776 -  after zoom scrolling overwrites content

Comment 1

[Karel Jára]

I can confirm this on other sites.

For example www.winsupersite.com. Scrolling even if not zoomed is very slow, much slower than in any other browser. When zoomed its almost unbareable how slow the scrolling is. It doesn’t matter what you are scrolling the page by (mouse wheel, dragging the scrollbar, arrow keys).

I’ve been noticing this for long time in stable Firefox 3 and nothing has changed in oncoming Firefox 3.5.

Comment 2

[Karel Jára]

Let’s compare with the bugs:

Bug 483394 – Very slow scrolling/rendering  
Bug 425234 – Full page zoom very slow on ajaxian.com
Bug 452714 – W3C’s page scrolls very slowly

Comment 3

[Trustin Lee]

I searched for similar bug reports and here are my findings:

* Bug 479852
* Bug 480806
* Bug 425234
* Bug 426388

And here's another easy way to reproduce the problem:

1) Load your mailbox in Google Mail
2) Full-zoom to 200%
3) Enable the 'Tasks' labs feature
4) Login again to your GMail account with the 'Tasks' labs feature enabled.
5) Scroll now becomes seriously slow.

Comment 4

[Alice0775 White]

Changesets between the above regression range(comment #0)
http://hg.mozilla.org/mozilla-central/pushloghtml?startdate=2008-12-02+03%3A45%3A10&enddate=2008-12-03+04%3A18%3A57

And for branch build is
Works fine:
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b3pre) Gecko/20081226 Shiretoko/3.1b3pre
Broken:
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b3pre) Gecko/20081227 Shiretoko/3.1b3pre
Changesets:
http://hg.mozilla.org/releases/mozilla-1.9.1/pushloghtml?startdate=2008-12-26+03%3A42%3A26&enddate=2008-12-27+03%3A44%3A37

Judging from the above changesets,
The candidate of regression is either of the following bugs. 
Bug 463307
Bug 465928
Bug 465475
Bug 467283

Comment 5

[Karel Jára]

It really seems to have even worsen in 3.5 Beta in comparation with stable 3.0 version. Really nicely visible on the page I’ve already written about: www.winsupersite.com. In 3.5 Beta 4 it’s almost unbareable.

Comment 6

[Jason Tackaberry]

I see this also on Linux (however I can't update the platform field in this bug).

Text zoom is fine.  Page zoom at any value other than 100% renders some sites unusable.  This did not occur with 3.0.

I offer http://scienceblogs.com/pharyngula/ to the list of test cases.

Comment 7

[Dimitrios]

Ok, maybe I  will regret for that but I have to duplicate this one to a similar
bug which has a minimized test case. Please don't spam the other bug with
confirm comments.

Comment 8

[Dimitrios]

Un-duplicating, per comment https://bugzilla.mozilla.org/show_bug.cgi?id=487267#c9

Comment 9

[Jason Tackaberry]

I'm curious if the patch in bug 489389 fixes this?

Comment 11

[Alice0775 White]

This problem does not happen anymore.
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b4pre) Gecko/20100814 Minefield/4.0b4pre ID:20100814040443

I change status to WORKS FOR ME