Bug 212371 – New page loaded with a negative content offset for the first time

• Status: NEW
• Component: Page Loading

[Daohan Chong]

On Safari Version 13.1 (15609.1.20.111.8) of macOS, there is a bug:
When opening a page for the first time, the content has a negative offset on the vertical direction.

This can also be reproduced with macCatalyst and WKWebView.


Repro steps:

1. Search some keywords on Google, such as "Keyshot"
2. Open keyshot.com on Google search results
3. Observe the content offset

If you resize the Safari window, the bug will disappear.

[Daohan Chong]

Created attachment 400241 [details]
Demo project (need to be run on macCatalyst)

Attaching a demo project.

Please note that this should be run on mac catalyst

[Daohan Chong]

Created attachment 400242 [details]
Screenshot

Attaching a screenshot

[Radar WebKit Bug Importer]

<rdar://problem/63622170>

[Tim Horton]

This reproduces for me.

You can work around this (I tried in your test app) by avoiding the safe area:

webView.frame = view.bounds.inset(by: view.safeAreaInsets)

but ... we should figure out why this isn't working, since it works fine on iOS.

[Daohan Chong]

This bug still exists on Version 14.0 (16610.1.23.1.3), Big Sur beta

[Daohan Chong]

Adding a new radar: FB8704777

[David Kilzer (:ddkilzer)]

(In reply to Daohan Chong from comment #6)
> Adding a new radar: FB8704777

The interesting thing about this bug report (per the reporter) is that it demonstrates that this bug also affects MobileSafari.

[Daohan Chong]

(In reply to David Kilzer (:ddkilzer) from comment #7)
> (In reply to Daohan Chong from comment #6)
> > Adding a new radar: FB8704777
> 
> The interesting thing about this bug report (per the reporter) is that it
> demonstrates that this bug also affects MobileSafari.

Desktop Safari is also affected. Not 100% repro.

[Daohan Chong]

Any updates on this bug?

It can still be reproduced on macOS 12.0 beta.

In addition, on iOS 14.x, `SFSafariViewController` can sometimes repro this bug.