https://drafts.csswg.org/css-page-3/#page-size-prop says that "size" is a property but it's clearly wrong, it's a descriptor, see https://github.com/w3c/csswg-drafts/issues/5969 Then, CSS.supports("size: initial"); // Expected: false // Webkit: true // Blink: true // Gecko: false [...getComputedStyle(document.documentElement)].includes("size"); // Expected: false // Webkit: true // Blink: false // Gecko: false Note "system" for @counter-style works well everywhere: https://drafts.csswg.org/css-counter-styles-3/#counter-style-system CSS.supports("system: initial"); // false [...getComputedStyle(document.documentElement)].includes("system"); // false
<rdar://problem/92963022>
(In reply to Oriol Brufau from comment #0) > https://drafts.csswg.org/css-page-3/#page-size-prop says that "size" is a > property but it's clearly wrong, it's a descriptor, see > https://github.com/w3c/csswg-drafts/issues/5969 > > Then, > > CSS.supports("size: initial"); > // Expected: false > // Webkit: true > // Blink: true > // Gecko: false Bug 217802 fixes this (as it's needed to avoid various asserts). > > [...getComputedStyle(document.documentElement)].includes("size"); > // Expected: false > // Webkit: true > // Blink: false > // Gecko: false This is a much broader issue, see https://github.com/w3c/csswg-drafts/issues/5649. > Note "system" for @counter-style works well everywhere: > https://drafts.csswg.org/css-counter-styles-3/#counter-style-system > > CSS.supports("system: initial"); // false > [...getComputedStyle(document.documentElement)].includes("system"); // > false Is that just because @counter-style is disabled by default? If you try "unicode-range" (of @font-face) you should see the same as with "size".
(In reply to Sam Sneddon [:gsnedders] from comment #2) > This is a much broader issue, see > https://github.com/w3c/csswg-drafts/issues/5649. Oh, finally found it: bug 217627. Basically I think this is just reporting the symptoms of CSS.supports returning true for descriptors (dunno if we have any actual specific bug for that), which Bug 217802 fixes, and that other bug. Maybe close as dupe?
Pull request: https://github.com/WebKit/WebKit/pull/15870