Bug 287472 – document.caretPositionFromPoint returns null over SVG elements and elements with `-webkit-user-select: none`

• Status: RESOLVED
• Resolution: FIXED
• Component: DOM

[Anne van Kesteren]

<svg width=100 height=100><circle cx=50 cy=50 r=50 /></svg>
<script>
range = document.caretRangeFromPoint(50, 50);
w(range);
</script>

logs null instead of a range pointing to the svg element. This can make shadow trees containing SVG observable (as we return null rather than a range for the host element). I discovered this in bug 286803.

https://software.hixie.ch/utilities/js/live-dom-viewer/?%3Csvg%20width%3D100%20height%3D100%3E%3Ccircle%20cx%3D50%20cy%3D50%20r%3D50%20%2F%3E%3C%2Fsvg%3E%0A%3Cscript%3E%0Arange%20%3D%20document.caretRangeFromPoint(50%2C%2050)%3B%0Aw(range)%3B%0A%3C%2Fscript%3E

[Radar WebKit Bug Importer]

<rdar://problem/145038689>

[Brent Fulgham]

Shouldn't this be `document.caretPositionForPoint()`?

[Brent Fulgham]

https://software.hixie.ch/utilities/js/live-dom-viewer/saved/13608

[Anne van Kesteren]

I'm pretty sure both use the same underlying infrastructure and we need to fix that as this ends up exposing shadow roots when they use SVG.

[Aditya Keerthi]

Pull request: https://github.com/WebKit/WebKit/pull/48997

[Aditya Keerthi]

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/54176

[EWS]

Committed 298313@main (74c2e1e966aa): <https://commits.webkit.org/298313@main>

Reviewed commits have been landed. Closing PR #48997 and removing active labels.