1313664 - White flashes displayed on Pinterest while scrolling using END and HOME keys

Status: RESOLVED INVALID

(Core :: Web Painting, defect)

Description

[Camelia Badau [:cbadau], Desktop Test Engineering]

[Affected versions]:
- latest Nightly 52.0a1 (2016-10-28)
- latest Aurora 51.0a2 (2016-10-28)
- Firefox 50 Beta 11
- Firefox 41.0.2 (2015-10-13)

[Affected platforms]:
- Windows 7 x64
- Mac OS X 10.11

[Steps to reproduce]:
1. Launch Firefox and go to https://www.pinterest.com/ . 
2. Scroll multiple times the page using END and HOME keys.  

[Expected result]:
- The scrolling is smooth, without any jerkiness or rendering issues.

[Actual result]:
- White flashes displayed while scrolling the page using END and HOME keys. Please see issue here: http://imgur.com/a/HPzPB  

[Regression range]:
- The issue is also reproducible on Firefox 41.0.2 (buildID: 20151013193107)

[Additional notes]:
- The issue is not related to APZ: the issue is reproducible with "layers.async-pan-zoom.enabled" set to false.

Comment 1

[Andrew Overholt [:overholt]]

This is just checkerboarding, right, kats?

Comment 2

[Botond Ballo [:botond]]

(In reply to Andrew Overholt [:overholt] from comment #1)
> This is just checkerboarding, right, kats?

This suggests otherwise:

> [Additional notes]:
> - The issue is not related to APZ: the issue is reproducible with
> "layers.async-pan-zoom.enabled" set to false.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

What Botond said. Also the fact that it's reproducible on Firefox 41.0.2 which didn't have APZ enabled at all. It might very well be "fake checkerboarding" in that Pinterest doesn't populate the DOM with content until you scroll down, but it could be something else.

Comment 4

[Andrew Overholt [:overholt]]

(In reply to Kartikaya Gupta (email:[e-mail]) from comment #3)
> It might very well be "fake
> checkerboarding" in that Pinterest doesn't populate the DOM with content
> until you scroll down, but it could be something else.

Oh, that's interesting. And the video from comment 0 does indeed look like that! Camelia, could this perhaps be network lag?

(Sorry for my incorrect knee jerk diagnosis, APZ folks :)

Comment 5

[Camelia Badau [:cbadau], Desktop Test Engineering]

I've retested on latest Nightly 53.0a1 (2016-12-04) and the issue is still reproducible.

Also, I've reproduced the issue on a different network. Therefore, I don't think that's a network lag.

Comment 6

[Desigan Chinniah [:cyberdees] [:dees] [London - GMT]]

Any other ideas here - to move this forward?

Comment 7

[Andrew Overholt [:overholt]]

I recovered my Pinterest password and tried this again. It happens the same in Chrome so I don't think this is a Gecko or Firefox bug.

FWIW, they do seem to be serving different content to different UAs: in Firefox I get some sort of infinitely-growing list of photos when I first log in vs. in Chrome I only get that if I search for something. But I think that's irrelevant to this bug.

The resolution being INVALID here isn't at all reflective of the value of bug reports like this. Thanks, Camelia.

Comment 8

[Desigan Chinniah [:cyberdees] [:dees] [London - GMT]]

Should we report this to them via our Dl since it's potentially cross browser? And do we perhaps have a potential solution for them to attempt.

Comment 9

[Mike Taylor [:miketaylr]]

We could let them know, but I don't think we fully understand the bug, or have a solution (and since it's happening in multiple browsers, it suggests a bug on their end).

Comment 10

[Karl Dubost💡 :karlcow]

The discussion with Pinterest suggests that there will be changes and that they will sit with some Firefox engineers and perform some in-depth profiling of scrolling performance.