REGRESSION (visionOS 1.2 beta): USDZ blobs open in the browser instead of opening in the user's space

• Component: WebKit Misc.
• Status: RESOLVED DUPLICATE

[Felix Herbst]

Since the latest visionOS 1.2 beta, opening generated USDZ blobs from websites in the user's space doesn't work anymore.
Expected: Clicking on a rel=ar link with a USDZ blob of mime type "model/vnd.usdz+zip" will show the model in the user's space (potentially after asking one more time if it should be downloaded instead).
Actual: Clicking on a rel=ar link with a USDZ blob will navigate the current page to a blank new page with a "blob:" URL.

Can be reproduced on these pages – all of them work on visionOS 1.1:

1. https://modelviewer.dev/ (click on the AR icon in the bottom right corner)
  - a "View" button shows up, but then navigates away from the current page and to a "blob:" URL page
  - when clicking on that page, after a few more steps, can display the model in the user's space
  - Expected is that the model opens in the user's space directly instead of first opening as fullscreen page etc.

2. https://engine.needle.tools/samples/musical-instrument/ (click on "Open in QuickLook")
  - this page uses an iframe that opens the Blob. Here, "View" is not an option, only "Download", when clicking "Open in QuickLook"
  - so it seems that there's an additional bug with blobs from inside iframes

3. https://engine.needle.tools/samples-uploads/musical-instrument/ (Click on "Open in QuickLook")
  - a "View" button shows up, but navigates away to a "blob:" URL page
  - when clicking on that page, nothing happens

Potentially related to the "full-screen model element" feature flag, but that is turned off – I just know that when that was turned on in the past the behaviour was somewhat similar. rel="ar" links should not ever open as fullscreen model elements.

Potentially related to https://bugs.webkit.org/show_bug.cgi?id=259141 and https://bugs.webkit.org/show_bug.cgi?id=258957

[Radar WebKit Bug Importer]

<rdar://problem/126375974>

[Mike Wyrzykowski]

*** This bug has been marked as a duplicate of bug 272321 ***

[Mike Wyrzykowski]

Re-opening for pull request https://github.com/apple/WebKit/pull/1205

[Mike Wyrzykowski]

*** This bug has been marked as a duplicate of bug 272321 ***