Bug 238616

Summary:	[iOS] WebKit misreports scroll position in requestAnimationFrame
Product:	WebKit	Reporter:	Brent Fulgham <bfulgham>
Component:	Scrolling	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	augus.dupin, bfulgham, graouts, jack, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Brent Fulgham 2022-03-31 10:50:09 PDT

Converted from a codepen.io test case:

// iOS misreports scroll position! Set it, check it immediately and it's correct but then 
// on the next requestAnimationFrame (or sometimes in the same one), it REVERTS to the previous scroll position!!!

You must run this on iOS Safari in the /debug/ window of CodePen so that it's not in an iframe https://codepen.io/GreenSock/debug/16c435b12ef09c38125204818e7b45fc?editors=0010

Comment 1 Radar WebKit Bug Importer 2022-03-31 10:50:41 PDT

<rdar://problem/91113529>

Comment 2 Simon Fraser (smfr) 2023-01-17 15:48:41 PST

<rdar://88342742>