Bug 237403 - Can't transfer an ImageBitmap through a MessageChannel
Summary: Can't transfer an ImageBitmap through a MessageChannel
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Canvas (show other bugs)
Version: Safari Technology Preview
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2022-03-02 18:54 PST by Kaiido
Modified: 2022-03-09 18:55 PST (History)
7 users (show)

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Description Kaiido 2022-03-02 18:54:53 PST 
Transferring an ImageBitmap through the ports of a MessageChannel makes the `data` of the MessageEvent `null`.  
This doesn't happen when only cloning the ImageBitmap instead of transferring it. This also doesn't happen when transferring from a Worker's `postMessage` (this is being tested by WPT), nor when transferred from an WindowProxy, i.e this only concerns MessageChannel.

You can see a minimal repro at https://jsfiddle.net/1kzxvad9/
Comment 1 Radar WebKit Bug Importer 2022-03-09 18:55:15 PST 
<rdar://problem/90072516>