Bug 321274 – Page freezes with CSS transition duration calc(infinity * 1s)

• Component: Animations
• Status: RESOLVED FIXED

[Razvan Caliman]

Created attachment 480964 [details]
test case

Found on https://nerdy.dev/css-infinity-use-cases in the Perma-state example. Attached reduced test case.

Hovering over elements that have `transition: background calc(infinity * 1s) ease;` freezes the page. Scrolling is unresponsive.

[Radar WebKit Bug Importer]

<rdar://problem/184322389>

[Razvan Caliman]

Created attachment 480965 [details]
Screen recording test case Safari

[Razvan Caliman]

Created attachment 480966 [details]
Screen recording test case Chrome

[Razvan Caliman]

Created attachment 480967 [details]
Screen recording nerdy.dev

[Antoine Quint]

We're hung in `UnitBezier::solveCurveX()`.

[Antoine Quint]

This is similar to bug 297596 which we addressed by adding this check to `TimingFunction::transformProgress()`:

        if (function.isLinear() || duration >= std::numeric_limits<double>::max())
            return progress;

In this case, we're somehow below `std::numeric_limits<double>::max()` (1.7266105117235917E+308), probably due to how we resolve the value from the `calc(infinity * 1s)` value. Will need to find a better check.

[Antoine Quint]

Pull request: https://github.com/WebKit/WebKit/pull/71783

[Antoine Quint]

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/61991

[EWS]

Committed 320034@main (029da7d3d074): <https://commits.webkit.org/320034@main>

Reviewed commits have been landed. Closing PR #71783 and removing active labels.