[csswg-drafts] [css-transitions] `transition-property` needs to specify case sensitiveness (#8025)

Loirooriol has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-transitions] `transition-property` needs to specify case sensitiveness ==
https://drafts.csswg.org/css-transitions-1/#transition-property-property defines the grammar of `transition-property` as

```
none | [ all | <custom-ident> ]#
```

And https://drafts.csswg.org/css-values-4/#identifier-value defines `<custom-ident>` to be "fully case-sensitive".

However, standard properties (excluding custom properties) are ASCII case-insensitive, so it's not much clear how the comparison should be performed.

From the above I think I would expect:
 - Idents are kept as-is, no casing normalization
 - When checking if a property is in the list, comparisons are done case-insensitively if the property is case-insensitive, or case-sensitively if the property is case-sensitive.

But implementations normalize idents to lowercase when there is a case-insensitive match with a property that is case-insensitive:

```js
document.body.style.transitionProperty = "lOreMipsUm, cOloR, --Foo, --foO";
document.body.style.transitionProperty; // "lOreMipsUm, color, --Foo, --foO"
```



Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/8025 using your GitHub account


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Received on Saturday, 5 November 2022 21:33:46 UTC