Bug 231878

Summary:	REGRESSION (iOS 15): Safari toolbar shows & hides when scrolling within a scrollable element
Product:	WebKit	Reporter:	Alex Fox <alexfoxy>
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED INVALID
Severity:	Normal	CC:	bfulgham, marcel.webkit, michal, simon.fraser, smoley, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	Safari 15
Hardware:	iPhone / iPad
OS:	Other

Description Alex Fox 2021-10-17 05:29:25 PDT

On iOS 15 scrolling within an element causes the window to resize / toolbar to disappear. On iOS 14 this would only happen when the body scrolled.

Video of bug: https://www.youtube.com/watch?v=F7cwYdw1rnc

Also see difference in behaviour in iOS14/15: 
iOS 15: https://i.stack.imgur.com/ctXmi.gif
iOS 14: https://i.stack.imgur.com/9QcC2.gif

I have tried various fixes e.g. overscroll-behavior to no avail.

Will this be fixed in the future?

Comment 1 Radar WebKit Bug Importer 2021-10-17 18:05:02 PDT

<rdar://problem/84352772>

Comment 2 Smoley 2021-10-18 12:27:54 PDT

Thanks for filing, I can reproduce this the latest iOS 15.1 beta using the test page at https://u7toi.csb.app. This does not reproduce for me on iOS 14. Ccing the relevant engineers. This may be a MobileSafari issue rather than a WebKit bug.

Comment 3 Alex Fox 2021-10-24 23:24:33 PDT

Thanks. Do you have a sense on if this will get fixed or if it is working as intended?

Comment 4 marcel laverdet 2021-12-01 17:35:54 PST

Since iOS is implementing non-standard behavior here, as a developer, I would love to see a non-standard vendor prefix CSS property to opt in or out. We're currently running into the opposite behavior where the address bar never minimizes since the bulk of our content is in a scrollable div.

Comment 5 Michal Sienkiewicz 2021-12-20 05:19:16 PST

I'm having the same issues. When iOS 15 released first, any pop-up dialogs did not resize at all, revealing the content of underlying page. I managed to fix it as described in this article: https://pqina.nl/blog/how-to-prevent-scrolling-the-page-on-ios-safari/. 

Still, dialog resizing is very clucky, as you can see on the bug video from @Alex Fox. Any other resources that could help with that?

Comment 6 Brent Fulgham 2022-02-10 10:32:28 PST

The Safari team confirmed this was an intentional behavior change.