[csswg-drafts] Merge error handling section into evaluating section (#7595)

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

== Merge error handling section into evaluating section ==
At this point, it's not clear what the motivation to have https://andreubotella.com/csswg-auto-build/mediaqueries-4/#error-handling as a separate section to https://andreubotella.com/csswg-auto-build/mediaqueries-4/#evaluating is.

The current split leads to some ambiguities in places:

> An unknown [<media-type>](https://andreubotella.com/csswg-auto-build/mediaqueries-4/#typedef-media-type) must be treated as not matching.

What does "not matching" mean, given "a media query is a logical expression that is either true or false"? (This also runs into #7594 given we don't define how to evaluate `<media-type>`.)

> An unknown [<mf-name>](https://andreubotella.com/csswg-auto-build/mediaqueries-4/#typedef-mf-name) or [<mf-value>](https://andreubotella.com/csswg-auto-build/mediaqueries-4/#typedef-mf-value), or a feature value which does not matches the value syntax for that [media feature](https://andreubotella.com/csswg-auto-build/mediaqueries-4/#media-feature), results in the value “unknown”. 

Results in the value "unknown" for what? Does it make the `<media-feature>` unknown, or the closest parent `<media-condition>` unknown, or does it make the whole `<media-query>` unknown? Implementations currently differ here!

> A [<media-query>](https://andreubotella.com/csswg-auto-build/mediaqueries-4/#typedef-media-query) whose value is “unknown” must be replaced with not all.

But, as above, a media query is either true or false? What does it mean to "replace" a `<media-query>`?

It seems like we may well want to define the rewriting to `not all` in [Serializing Media Queries](https://andreubotella.com/csswg-auto-build/cssom-1/#serializing-media-queries) instead?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7595 using your GitHub account


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Received on Thursday, 11 August 2022 17:49:53 UTC