1755202 - Scrollbars flash on and off while resizing window with sticky footer

Status: RESOLVED DUPLICATE of bug 1748891

(Core :: Layout, defect, P3)

Description

[mark.j.fisher]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:97.0) Gecko/20100101 Firefox/97.0

Steps to reproduce:

I made a footer stick to the bottom of the window with

footer {
position: sticky;
top: 100vh;
}

Then I made the window large enough for the footer to show at th bottom of the window, and reduced the height of the window gradually.

Actual results:

While the window was tall enough for no scrollbars to be required, the scrollbars flashed on and off while the window was being resized.

This can be seen at https://www.markfisher.photo/dusk-to-dawn/.
I tried to attach a video, but submission of this form failed, possibly because of this.

Expected results:

The scrollbars should only have shown when the window become small enough for scrollbars to be required, as is the case in all other browsers I have tested.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Layout' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

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

The severity field is not set for this bug.
:emilio, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Reduced test-case.

Thanks for the report, I can reproduce when not using overlay scrollbars. It seems very long-standing, at least Firefox 58 shows the same issue.

Comment 4

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

The severity field is not set for this bug.
:emilio, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Daniel, I wonder if we should have a metabug for sticky positioning issues, just to make it a bit easier to find these. Wdyt?

Comment 6

[Daniel Holbert [:dholbert]]

Sure! Filed bug 1760901, alias sticky.

Comment 7

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

The testcase in comment 3 is fixed by bug 1748891. Tested on Nightly 127.0a1 (2024-04-26).