Bug 217509

Summary:	Element.requestFullscreen will unintended change document.activeElement
Product:	WebKit	Reporter:	abc
Component:	DOM	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	cdumez, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari Technology Preview
Hardware:	Mac
OS:	macOS 10.15

Description abc 2020-10-09 02:53:22 PDT

Element.requestFullscreen() will unintended change document.activeElement on Safari 14+ if Document include an input element.

Reproduce:
1. Open https://semibold.github.io/Fullscreen/test/index.html on Safari 14+
2. Select Consoles tab in DevTools
3. Run `document.body.appendChild(document.createElement('input'))` to insert an input element
4. Run `console.log(document.activeElement)` (log: document.body)
5. Click [Request] button to requestFullscreen on current page
6. Run `console.log(document.activeElement)` (log: input. Expected: document.body)

Comment 1 Radar WebKit Bug Importer 2020-10-09 18:10:20 PDT

<rdar://problem/70161671>