Bug 253196

Summary:	[Scroll Snap] Scroll snapping to a section taller than the viewport causes scroll to jump too far
Product:	WebKit	Reporter:	Zouhir <zouhir>
Component:	Scrolling	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari 16
Hardware:	Unspecified
OS:	Unspecified

Description Zouhir 2023-03-01 14:42:57 PST

iOS: 16.3.1
macOS: 13.2.1
Safari: 16 (stable)

What steps will reproduce the problem?
(1) Go to https://scroll-snap-demo.web.app/
(2) Scroll down all the way to the colorful sections (~3000px or so).
(3) Once on the *first* colorful section, scroll up (even gently if you want).

What is the expected result?
- Scroll up a reasonable amount, matching my gesture / fling momentum & distance.

What happens instead?
- Scroll shoots up way too much (3000px or more even with gentle scroll gesture), to the beginning of the tall div.

We have a crbug open to discuss how can we get rid of `scroll-snap-align: start` which might help addressing this issue too.

Comment 1 Zouhir 2023-03-01 14:44:17 PST

[Update: missing a link]

We have a crbug open to discuss how can we get rid of `scroll-snap-align: start` which might help addressing this issue too. Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1420439

Comment 2 Radar WebKit Bug Importer 2023-03-08 14:43:18 PST

<rdar://problem/106453370>