241433 2022-06-08 13:30:19 -0700 Make CSS custom properties that are invalid at computed value time guaranteed-invalid 2023-02-15 09:05:05 -0800 1 1 1 Unclassified WebKit CSS Safari 15 All All RESOLVED CONFIGURATION CHANGED BrowserCompat, InRadar P2 Normal --- 1 xiaozj webkit-unassigned augus.dupin bramus james0x57 justin_michaud koivisto ntim philip simon.fraser webkit-bug-importer oldest_to_newest 1874787 0 xiaozj 2022-06-08 13:30:19 -0700 Same as this Firefox bug: https://phabricator.services.mozilla.com/D116460 Also codepen demo: https://codepen.io/Miragecraft/pen/XWaLxNb In short, when assigning an invalid CSS custom property to another custom property, it makes the final value unset (which means "inherit" for custom properties) instead of initial. 1874968 1 augus.dupin 2022-06-09 05:35:08 -0700 WebKit's behaviour now differs from both Gecko's and Blink's, causing an interoperability issue. 1876066 2 webkit-bug-importer 2022-06-15 13:31:13 -0700 <rdar://problem/95234259> 1911496 3 philip 2022-11-10 03:08:51 -0800 Here's the relevant spec change: https://github.com/w3c/csswg-drafts/issues/5370 https://github.com/w3c/csswg-drafts/pull/6006 And Safari-only failures in WPT: https://wpt.fyi/results/css/css-variables/variables-substitute-guaranteed-invalid.html?run_id=6317090990981120&run_id=5097315145089024&run_id=5104235344035840&run_id=5084375415259136 The reason I noticed is because this issue was specifically called out in a freeform text comment from State of CSS 2022. 1933834 4 koivisto 2023-02-15 09:02:11 -0800 Is now working. 1933836 5 koivisto 2023-02-15 09:05:05 -0800 That is css/css-variables/variables-substitute-guaranteed-invalid.html WPT is passing.