[css-values-5] *Replace an attr() function* doesn't handle `raw-string`

[AtkinsSJ]

Replace an attr() function doesn't handle raw-string as a value. Step 4 says:

If syntax is null, return a CSS whose value is attr value.
NOTE: No parsing or modification of any kind is performed on the value.

...and then subsequent steps require parsing the attr value into tokens. I believe step 4 should be something like:

If syntax is either null or raw-string, ...

This would agree with the earlier text explaining <attr-type>:

If given as the raw-string keyword, or omitted entirely, it causes the attribute’s literal value to be treated as the value of a CSS string, with no CSS parsing performed at all (including CSS escapes, whitespace removal, comments, etc).

cc: @tabatkins

I'm happy to PR this later, I just want to check I'm understanding correctly first.

[tabatkins]

Yup, just an accidental omission on my part. Omitting and raw-string should behave the same here. (Those two possibilities should only differ in behavior wrt the default fallback.)

[AtkinsSJ]

Great, thank you!