Bug 239288

Summary:	Scroll chaining on iOS does not occur in certain overflow cases
Product:	WebKit	Reporter:	harry-moore
Component:	Scrolling	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED MOVED
Severity:	Major	CC:	bfulgham, harry-moore, nmouchtaris, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	iPhone / iPad
OS:	iOS 15

Description harry-moore 2022-04-13 09:21:49 PDT

If we scroll on an element that is overflowing, its scroll should chain to scroll its parent when its scroll position is at the end.

In this codepen (https://codepen.io/HazzMan2409/pen/KKZxxGx) this does not happen when you scroll vertically on the child.

There is an element in between the two vertically scrolling elements that scrolls in the opposite direction, I believe it is that element that is causing the bad behavior.

Note that this behaves fine on desktop Safari.

Comment 1 Ryan Haddad 2022-04-21 17:12:13 PDT

rdar://92112692

Comment 2 Brent Fulgham 2022-06-23 16:36:40 PDT

We believe this was fixed in the current release.

Comment 3 Simon Fraser (smfr) 2022-06-23 16:45:28 PDT

Actually not fixed, but it's represented internally by the above radar.