1635155 - Checkerboarding on sticky elements

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect, P3)

Description

[fabioturrin]

Attachment: demo.html

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.129 Safari/537.36 Edg/81.0.416.68

Steps to reproduce:

My user agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:77.0) Gecko/20100101 Firefox/77.0

1. Open attached html file
2. Quickly drag the slider of the vertical scroll bar

Actual results:

The sticky elements disappears until you stop scrolling (checkerboarding), also the grid content disappears.

Expected results:

The scrolling should be smooth, without flickering. The fixed headers (position: 'sticky') should always be visible, even while scrolling.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[fabioturrin]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1424714#c21

Comment 3

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

Thanks for the test case! I can reproduce the problem on Windows with the latest nightly build, with WebRender disabled. With WebRender enabled the behaviour is much better, there's some slight flickering but the contents seem to render pretty consistently and as far as I can tell the header is always there. With WebRender disabled it does look pretty bad.

Comment 4

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is P3 (Backlog,) indicating it has been triaged, the bug's Severity is being updated to S3 (normal.)

Comment 5

[Jeff Muizelaar [:jrmuizel]]

Attachment: sticky-slow

Here's a new version that spins for a bunch of time in requestAnimationFrame. This makes the problem more obvious.

Comment 6

[Hiroyuki Ikezoe (:hiro)]

Confirmed I can no longer see any sticky elements' flickers either on the test case in comment 0 or the test case in comment 5 on the latest nightly (the build id: 20211014212856). Though I do still see checkerboarding on the scrolling content itself, it's originally there before bug 1730998.