Bug 265000 – FontFace with data: URI crashes Worker

• Component: New Bugs
• Status: RESOLVED FIXED

[Jacob Bandes-Storch]

Steps to reproduce:
Tested in Safari 17.1 (19616.2.9.11.7) and Technology Preview (Safari 17.4, WebKit 19618.1.5.2)

1. Create a HTML file with the following content:

    <script>
    new Worker(URL.createObjectURL(new Blob([`(async()=>{
    try {
        await new FontFace("ABC", "url(data:font/woff2,abcd) format('woff2')").load().catch(e=>console.error("rejected",e));
        console.log("done")
    } catch(e) {
        console.error("caught",e)
    }
    })()`])))
    </script>

2. Load the page, open the console and see the following output:

    [Error] Cannot load data:font/woff2,abcd.
    [Error] Failed to load resource: Cross origin requests are not allowed when using same-origin fetch mode. (data:font/woff2,abcd, line 0)

Notice that the "rejected", "caught", and "done" log messages do not appear -- the Worker seems to be completely dead.


Expected behavior:
- Ideally, this method of font loading would just work.
- If loading the data: URL is not permissible, then the error should be catchable via .catch() or try/catch, it should not break the entire Worker.

Workaround:
- Using fetch() to load the data: url and passing an ArrayBuffer to the FontFace constructor seems to be a valid workaround. (example: https://github.com/foxglove/studio/pull/7139)

[youenn fablet]

<rdar://118546120>

[youenn fablet]

It might be the promise never rejects/resolves.

[youenn fablet]

Pull request: https://github.com/WebKit/WebKit/pull/20742

[Jacob Bandes-Storch]

Yes, good catch, I guess the `await` in my sample code was a mistake and the worker is not broken :)  Thank you for the quick fix!

[EWS]

Committed 271213@main (b1f4d8147c3c): <https://commits.webkit.org/271213@main>

Reviewed commits have been landed. Closing PR #20742 and removing active labels.