Bug 220593

Summary: Failed HTML validation will lead to double elements after zooming
Product: WebKit Reporter: Christian Burtchen <christian.burtchen>
Component: CompositingAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 14   
Hardware: iPhone / iPad   
OS: iOS 14   
Attachments:
Description Flags
Screenshot from example project none

Description Christian Burtchen 2021-01-13 09:06:35 PST 
Created attachment 417541 [details]
Screenshot from example project

This issue does not reproduce with macOS as far as I could test. On an iPhone 11 running iOS 14.3, we could reliably reproduce it in both production code as well as simplified version:

- have a form with HTML validation, such as an input date element with a maximum date (see example) or a required radio choice
- provide input that is invalid, such as a date beyond the range and submit, or attempt to submit without the required radio choice
- as expected, submission itself will not work, and the Webkit UI will provide feedback on what failed
- zooming NOW (pinch to zoom on iOS for instance), the Submit button will appear multiple times during the zoom process while other elements are scaled properly and appear only once

Example screenshot attached, super minimalist example at https://2300h.csb.app/
Comment 1 Christian Burtchen 2021-01-13 09:08:00 PST 
Our team was also able to reproduce this on other iOS devices (iPhone 7) and versions (14.2)
Comment 2 Radar WebKit Bug Importer 2021-01-20 09:07:15 PST 
<rdar://problem/73406594>
Comment 3 Simon Fraser (smfr) 2021-01-20 11:39:01 PST 

*** This bug has been marked as a duplicate of bug 218004 ***