Bug 313665 – REGRESSION (296844@main): drop-shadow and translation transforms render incorrectly clipped

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Jonathan Deutsch]

Created attachment 479377 [details]
Reproduction document

The drop-shadow filter and a transform:translate() on a div can result in in a nested div being clipped if it also uses a transform:translate(). Please see this basic example:

```
<div style="filter: drop-shadow(black 0px 0px 5px); transform: translateX(48px) translateY(36px); width: 40px; height: 40px;">
	<div style="position: absolute;">
		<div style="background-color:cyan; border-radius: 50%; width: 142px; height: 142px; transform: translateX(-50px) translateY(-50px);"></div>
	</div>
</div>
```

Attached as bug.html. I also attached screenshots.

This works correctly on Safari Version 18.6 (20621.3.11.11.3) on macOS 15.6.
This works correctly on the latest Chrome/Firefox.
This is a bug on at least Safari Version 26.5 (20624.2.4.18.2) on macOS 15.7.7 (24G716).

It was reported to us as early as Jan 12, 2026 on macOS 14.8.3, but I did not have the Safari version or repro steps back then. But it seems likely this was a Safari 26 regression at some point.

This affects users of Tumult Hype https://tumult.com/hype/.

[Jonathan Deutsch]

Created attachment 479378 [details]
How it should look (older version of Safari)

[Jonathan Deutsch]

Created attachment 479379 [details]
How the bug looks on Safari 26.5

[Jonathan Deutsch]

This reproduces in the Safari Technology Preview Release 242 (WebKit 20625.1.13.19.1) and the latest nightly 312297@main.

[Radar WebKit Bug Importer]

<rdar://problem/175905543>

[Ahmad Saleem]

Broken on Safari 26.4 as well.

[Alexey Proskuryakov]

Created attachment 479404 [details]
different result for 18.6

Curiously, I'm getting a different yet result using Safari 18.6 on macOS 15.6.

[Alexey Proskuryakov]

Confirmed that the extra clipping started with Safari 26 though.

[Simon Fraser (smfr)]

Possibly the same as bug 312584.

[Simon Fraser (smfr)]

No, this is a different issue.

[Simon Fraser (smfr)]

Caused by https://commits.webkit.org/296844@main

[Simon Fraser (smfr)]

Pull request: https://github.com/WebKit/WebKit/pull/64966

[EWS]

Committed 313316@main (42cae1dc020a): <https://commits.webkit.org/313316@main>

Reviewed commits have been landed. Closing PR #64966 and removing active labels.