266918 2023-12-27 18:40:49 -0800 drawImage(detachedOffscreenCanvas) is supposed to throw 2024-02-13 02:52:13 -0800 1 1 1 Unclassified WebKit Canvas Safari Technology Preview Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 tristan.fraipont webkit-unassigned dino heycam mattwoodrow webkit-bug-importer oldest_to_newest 2002117 0 tristan.fraipont 2023-12-27 18:40:49 -0800 When transferring an OffscreenCanvas its width and height attributes become zero. Drawing such a detached OffscreenCanvas through a 2D context's drawImage() method should thus throw a DOMException (from https://html.spec.whatwg.org/multipage/canvas.html#check-the-usability-of-the-image-argument). However it seems the check for the image size still uses the dimension of the OffscreenCanvas from before it got detached as can be seen in both fiddles: https://jsfiddle.net/9zvx6bok/ & https://jsfiddle.net/9zvx6bok/1/ In the first one we draw a detached OffscreenCanvas on a 2D context, where this shouldn't be possible since the reported dimensions are both zero. In the second one, we do set the OffscreenCanvas's dimension to zero before detaching it. This one throws as expected, demonstrating that drawImage() checks the dimensions before the transfer happened. 2002483 1 tristan.fraipont 2024-01-02 02:07:59 -0800 Pull request: https://github.com/WebKit/WebKit/pull/22297 2002916 2 webkit-bug-importer 2024-01-03 18:41:13 -0800 <rdar://problem/120451062> 2013105 3 ews-feeder 2024-02-13 02:52:11 -0800 Committed 274534@main (5dbd0444ac2e): <https://commits.webkit.org/274534@main> Reviewed commits have been landed. Closing PR #22297 and removing active labels.