Bug 282529

Summary:

FileSystemFileHandle can't be cloned

Product:

WebKit

Reporter:

Fabian <me>

Component:

Website Storage

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

cdumez, karlcow, sihui_liu

Priority:

Version:

Safari 18

Hardware:

Mac (Apple Silicon)

OS:

macOS 15

URL:

https://young-animated-science.glitch.me

Attachments:

Description	Flags
Screenshot showing the behaviour in Safari, Firefox and Chrome.	none

Fabian

Reported 2024-11-04 02:31:15 PST

Created attachment 473122 [details] Screenshot showing the behaviour in Safari, Firefox and Chrome. When trying to clone a `FileSystemFileHandle` with `structuredClone` Safari will throw the following error: ``` [Error] DataCloneError: The object can not be cloned. structuredClone Modulcode — young-animated-science.glitch.me:46 Modulcode (young-animated-science.glitch.me:50) ``` See a demo of this behaviour on https://young-animated-science.glitch.me. This works fine in Firefox 131 and Chrome 130. According to the spec https://fs.spec.whatwg.org/#api-filesystemfilehandle `FileSystemFileHandle` is `Serializable` and should therefore work with `structuredClone`. ## Use Case Since Safari only supports writing to OPFS from a Worker I tried to send the file handle as part of the `postMessage`, which failed with the same error since `postMessage` uses the structured clone algorithm to send data to a Worker.

Attachments
Screenshot showing the behaviour in Safari, Firefox and Chrome. (617.08 KB, image/png) 2024-11-04 02:31 PST, Fabian	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Karl Dubost

Comment 1 2024-11-10 22:01:58 PST

Thanks for the report. That looks like a duplicate of Bug 256712 *** This bug has been marked as a duplicate of bug 256712 ***

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