Bug 251378

Summary: Fullscreen page appears completely misaligned on scrolling up and down
Product: WebKit Reporter: joemerramos
Component: WebKit APIAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: ajuma, jer.noble, ntim, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: iPhone / iPad   
OS: Unspecified   
Attachments:
Description Flags
Reproducing bug none

Description joemerramos 2023-01-30 11:53:39 PST 
Created attachment 464756 [details]
Reproducing bug

When using the fullscreen API, scrolling down then scrolling up will cause the fullscreen to misalign and cause the screen to be in a broken state making it hard for users to properly use or exit fullscreen mode. 

Steps to repro:

On Safari: 
1. Navigate to https://davidwalsh.name/demo/fullscreen.php 
2. Tap on the Launch Fullscreen button
3. Tap on the > Back to: Fullscreen API button 
4. Scroll up and scroll down

Observed results:
Fullscreen page is misaligned on scrolling up and down 

Expected results:
Fullscreen page should not misalign on  scrolling up and down
Comment 1 Simon Fraser (smfr) 2023-01-30 13:21:18 PST 
Is this new in iOS 16?
Comment 2 Radar WebKit Bug Importer 2023-01-30 13:23:00 PST 
<rdar://problem/104834393>
Comment 3 joemerramos 2023-01-30 13:30:39 PST 
I just tested on iOS 15.5 and was able to reproduce.