Bug 251754

Summary: Weird temporarily artifacts on over scrolling
Product: WebKit Reporter: Ebrahim Byagowi <ebrahim>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bfulgham, mmaxfield, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
weird temporarily artifacts
none
Artifacts
none
resize and scroll none

Description Ebrahim Byagowi 2023-02-05 02:59:37 PST 
Created attachment 464848 [details]
weird temporarily artifacts

Happens in both WebKit (6c4c9810) and Safari 16.2,

1. Open https://codepen.io/jh3y/pen/VwBgPxP
2. Scroll down and up, fast and slowly, like what is shown in the attachment.

Actual:
Weird artifacts will be seen sometimes specially when top overscroll happens.

Expected:
Like Chrome and Firefox

I saw this codepen from this tweet, https://twitter.com/jh3yy/status/1621564942175322112
Comment 1 Ebrahim Byagowi 2023-02-05 03:48:07 PST 
Created attachment 464849 [details]
Artifacts

Something similar also happen while scrolling of https://meodai.github.io/poline/ only in Safari and not Chrome and Firefox on an M1 MacBook Pro.
Comment 2 zalan 2023-02-05 07:02:16 PST 
Created attachment 464851 [details]
resize and scroll

I wasn't able to reproduce it but resizing the content frame makes the gallery move off center while it jumps right back soon after I star scrolling -(which looks very similar to what the attached "artifact" recording shows with the misplaced content). Firefox seems to always center the content.
Comment 3 Radar WebKit Bug Importer 2023-02-05 08:55:58 PST 
<rdar://problem/105058470>