Bug 307508 – AX: number stepper within collapsed details element in accessibility tree

• Component: Accessibility
• Status: RESOLVED FIXED

[Curtis Wilcox]

Created attachment 478307 [details]
Screen recording of VoiceOver navigating the example element-by-element

When a <input type="number"> element is within a collapsed <details> element, the input is (correctly) removed from the accessibility tree. However, between reading the <summary> element and the content that follows the <details>, macOS VoiceOver will read "0 stepper." 

While the VoiceOver cursor is on the stepper, the visual cursor surrounds the entire viewport. The stepper is not operable.
The number input and its stepper are not listed in the Rotor's Form Controls list while the details is collapsed. 
VoiceOver says "0 stepper" regardless of the value of the input.

The problem is not exclusive to <details> elements, it also happens to number inputs within a <div> styled with content-visibility: hidden.

Example:
https://cdpn.io/pen/debug/yyJGLZx

The problem has been reproduced on:

- Safari 26.2 on macOS 26.2
- Safari 26.1 on macOS 26.1
- Safari Technology Preview Release 235 on macOS 15.7.3
- Safari 26.2 on macOS 15.7.3

The problem did not occur on iOS 18.7.3.

[Radar WebKit Bug Importer]

<rdar://problem/170106659>

[Tyler Wilcock]

Pull request: https://github.com/WebKit/WebKit/pull/58589

[EWS]

Committed 308165@main (bd2f4d1c9a01): <https://commits.webkit.org/308165@main>

Reviewed commits have been landed. Closing PR #58589 and removing active labels.