Bug 265160 – REGRESSION(270890@main): Animation doesn't trigger when custom property initial value matches the first frame

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[Josh Collinsworth]

Created attachment 468691 [details]
The animation bug shown on my actual project code; you can see the radius change

Possible duplicate? https://bugs.webkit.org/show_bug.cgi?id=200702

I have an anchor that animates on hover. During the animation, the anchor's border radius goes back to 0 temporarily, and then reverts to the proper style once the animation is finished.

CodePen reproduction: https://codepen.io/collinsworth/pen/JjxLYzg/cbe544b1fb04cd6ff7df470151239465

[Radar WebKit Bug Importer]

<rdar://problem/118697176>

[Antoine Quint]

The CodePen behaves the same in Safari Technology Preview 138 and Chrome. Firefox however does not show any background on hover and I can see the reported issue in Safari on the macOS Sonoma 14.0. This got fixed since that release, as shown by Safari Technology Preview 138. Please reopen if that is not your experience.

[Simon Fraser (smfr)]

This still looks broken in recent Safari builds to me.

[Antoine Quint]

Looks like this was fixed… and then broken again!

[Antoine Quint]

I'll find out when it progressed originally, but this regressed recently with 270890@main. Let's keep this bug open to track this particular issue.

[Antoine Quint]

This originally progressed with 267321@main until the 270890@main regression.

[Antti Koivisto]

Pull request: https://github.com/WebKit/WebKit/pull/21047

[EWS]

Committed 271268@main (7687d03911da): <https://commits.webkit.org/271268@main>

Reviewed commits have been landed. Closing PR #21047 and removing active labels.

[Antti Koivisto]

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/43497