Bug 231493

Summary: Sticky element nested inside a sticky container is jumpy
Product: WebKit Reporter: jtran040
Component: ScrollingAssignee: Nobody <webkit-unassigned>
Severity: Normal CC: mrobinson, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 15   
Hardware: Mac (Intel)   
OS: macOS 10.15   
Description Flags
a screencast
Testcase none

Description jtran040 2021-10-10 16:47:11 PDT
Created attachment 440743 [details]
a screencast

It is similar to bug : https://bugs.webkit.org/show_bug.cgi?id=197660

However this one occurs in Safari 15 with a Mac(Intel).

Example URL: https://x80lf.csb.app

Steps to reproduce:
1. Open attached url
2. Scroll vertically

What is the expected behaviour?
The fixed purple cell should remain in the same position when scrolling.

What went wrong?
The fixed purple cell is jumpy and disappears and then reappears while scrolling fast with the mouse wheel.

If you remove position:sticky from the outside container, then it works as expected.
Comment 1 Sam Sneddon [:gsnedders] 2021-10-12 03:33:09 PDT
Created attachment 440915 [details]
Comment 2 Radar WebKit Bug Importer 2021-10-17 16:48:19 PDT
Comment 3 Martin Robinson 2021-11-09 03:50:30 PST
I think this might be a duplicate of bug 199915. Can you confirm whether or not this is failing with Safari Technology Preview (https://developer.apple.com/safari/technology-preview/)? Thanks!
Comment 4 Martin Robinson 2021-11-09 03:52:39 PST
I've tested this, so I'm marking it as a duplicate, but if this is still failing I can reopen the issue.

*** This bug has been marked as a duplicate of bug 199915 ***
Comment 5 jtran040 2022-01-12 14:21:39 PST
Thank you for fixing this. I've tested it in Safari Technology Preview and it is working as expected.