Bug 273681 – Virtual keyboard symbol toggle key unexpectedly emits Shift key events

• Component: New Bugs
• Status: NEW

[beeps]

Created attachment 471266 [details]
Shift key testing file

When using the numbers and symbols virtual keyboard in iOS/iPadOS, pressing the key to toggle between the initial and extended symbols views emits Shift key events in JavaScript.

## Repro steps

1. Open the attached HTML file on a device running iOS or iPadOS.
2. Focus the text input field to display the virtual keyboard.
3. Enter numbers and symbols view on the virtual keyboard ('123' button on the bottom left on the English keyboard on iOS, '.?123' on iPadOS). 
4. Toggle between the initial and extended symbols view (initially the '#+=' button, the text changes to '123' in the extended view).
5. Observe the output log below the text input.

On iPads that display two toggle keys on the virtual keyboard, this issue exists for both keys.

Note that the attached file includes instructions for various testing scenarios, however, this bug report only concerns the symbol toggle key. 

## Expected result

Toggling the virtual keyboard view should not emit JavaScript events.

## Actual result

Toggling the virtual keyboard emits `keydown` and `keyup` events indicating that the Shift key is being pressed and released.

## Additional information

This has been reproduced on versions of iOS 16.4 through 17.4.

[Radar WebKit Bug Importer]

<rdar://problem/127875741>