Bug 255592

Summary: [css-scroll-snap] scroll-to-top gesture on page with scroll-snap on html fails
Product: WebKit Reporter: Johannes Odland <johannes.odland>
Component: ScrollingAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: iPhone / iPad   
OS: iOS 16   
See Also: https://bugs.webkit.org/show_bug.cgi?id=245722
https://bugs.webkit.org/show_bug.cgi?id=251003
https://bugs.webkit.org/show_bug.cgi?id=255593
https://bugs.webkit.org/show_bug.cgi?id=255646
https://bugs.webkit.org/show_bug.cgi?id=272079
Attachments:
Description Flags
Video of the issue none

Description Johannes Odland 2023-04-18 05:22:08 PDT 
Created attachment 465959 [details]
Video of the issue

A scroll-to-tap gesture on a page with scroll-snap on the root/html element fails. 
After the browser has scrolled to the top, the browser snaps back to the previous snap position.

Steps to reproduce:
1. Open a page with scroll-snap on root (https://johannesodland.github.io/browserbugs/safari-scroll-snap-scroll-to-top-issue.html)
2. Scroll down so that the viewport snaps to a position further down on the page
3. Tap the status bar to scroll to the top of the page

Expected result: 
The browser scrolls to the top of the page and snaps to the first snap position.

Actual result: 
The browser scrolls to the topp of the page, then resnaps to the previous snap point which might be far down on the page
Comment 1 Radar WebKit Bug Importer 2023-04-18 09:54:01 PDT 
<rdar://problem/108206197>
Comment 2 Johannes Odland 2023-05-22 04:24:58 PDT 
Retested on iOS 16.5. The issue is still present.
Comment 3 Johannes Odland 2023-09-19 09:30:03 PDT 
Retested on iOS 17. The issue is still present.
Comment 4 Johannes Odland 2024-03-07 12:13:06 PST 
Retested On iOS 17.4. The issue dermed to be resolved 🎉