1774230 - Bad flickering when scrolling SF Chronicle article

Status: NEW

(Web Compatibility :: Site Reports, defect, P2)

Description

[Ryan VanderMeulen [:RyanVM]]

On the linked page, there's a background image that scrolls left to right at the start of the article as you scroll down while reading it. Once the "Against the backdrop of shuttered, graffitied storefronts..." box begins to scroll out of view, that image shifts to the top and the remaining article text scrolls into view. Right at the point of this transition, Firefox gets into an in-between state that causes extreme flickering. I've reproduced on Windows and Linux and as far as I can tell, it's a long-standing bug. It doesn't reproduce on Chrome.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

I don't see this because the page has a mis-configured CSP or something, images don't load in any browser here :(

Comment 2

[Ryan VanderMeulen [:RyanVM]]

Attachment: Screenshare showing flickering

This recording shows the flicker, but doesn't really do it justice due to framerate. It's actually faster.

Comment 3

[Mayank Bansal]

can repro. Its quite bad.
FWIW, a profile: https://share.firefox.dev/3zyWIft

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Ah, I can repro the flickering even without images.

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Attachment: Relevant code

The player gets into some "mini" / "not mini" loop.

Comment 6

[Emilio Cobos Álvarez (:emilio)]

Attachment: Screencast from 06-14-2022 06:12:59 PM.webm

It also gets stuck in Chrome, it just seems it's updated less often.

Comment 7

[Daniel Holbert [:dholbert]]

(In reply to Emilio Cobos Álvarez (:emilio) from comment #6)

It also gets stuck in Chrome, it just seems it's updated less often.

Confirmed, I see that here too.

Comment 8

[Daniel Holbert [:dholbert]]

Profile in Chrome: https://share.firefox.dev/3NUhnPC

It looks like x.port1.onmessage gets called just before the page toggles between states (in both Firefox and Chrome); that seems to be part of the oscillation, I think.

Comment 9

[Daniel Holbert [:dholbert]]

Per comment 6 and 8, it seems like this is a bug in the site, independent of browser (but it manifests differently in Chrome and feels-worse in Firefox).

--> Reclassifying as WebCompat. ni=ksenia to be sure it's on the radar of someone on that team, since it's pretty-bad. ksenia, do you happen to know if we've had any successful outreach to this site before?

Comment 10

[Ksenia Berezina [:ksenia]]

(In reply to Daniel Holbert [:dholbert] from comment #9)

Per comment 6 and 8, it seems like this is a bug in the site, independent of browser (but it manifests differently in Chrome and feels-worse in Firefox).

--> Reclassifying as WebCompat. ni=ksenia to be sure it's on the radar of someone on that team, since it's pretty-bad. ksenia, do you happen to know if we've had any successful outreach to this site before?

I've looked through webcompat reports, looks like we weren't in contact with them before. I've sent them an email about this problem, to one of the contacts listed here https://www.sfchronicle.com/customer_service/.

Comment 11

[Calin Tanase]

Attachment: sfchronicle glitch FF vs Chrome.mp4

The glitch reproduces on both Firefox and Chrome, do we keep it open or should we close it? Any response since you've contacted them?

Tested on:
Operating system: Windows 10
Browser/Version: Firefox Nightly 111.0a1 (2023-01-26) / Chrome 109.0.5414.75

Comment 12

[Ksenia Berezina [:ksenia]]

I didn't get any response from them unfortunately. I suppose we can keep this open as the issue is still reproducible for me.