254107 2023-03-17 22:48:42 -0700 REGRESSION: Incomplete offscreen canvas implementation causing NPEs 2023-03-19 21:37:06 -0700 1 1 1 Unclassified WebKit WebGL Safari 16 iPhone / iPad iOS 16 RESOLVED DUPLICATE 254071 P2 Normal --- 1 nb webkit-unassigned dino kbr kkinnunen oldest_to_newest 1942274 0 nb 2023-03-17 22:48:42 -0700 Code that requests WebGL contexts from Offscreen canvas when available is crashing on iOS 16.4 beta Code of the form: ``` const canvas = window.OffscreenCanvas ? new OffscreenCanvas(0, 0) : document.createElement('canvas') const ctx = canvas.getContext('webgl2') || canvas.getContext('webgl') ``` is leading to downstream errors in production sites due to ctx being null. 1942485 1 ap 2023-03-19 21:37:06 -0700 *** This bug has been marked as a duplicate of bug 254071 ***