1680933 - `:not` with type and class causes CSS rule to be discarded

Status: RESOLVED DUPLICATE of bug 933562

(Core :: CSS Parsing and Computation, defect)

Description

[jake]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0

Steps to reproduce:

:not(div.some-class),
body {
  color: green
}

<p>Hello World.</p>

Actual results:

Text is default black.

"Ruleset ignored due to bad selector" is seen in the console log.

Expected results:

Text should be green. No error should be reported in the console log (this is a valid selector).

Does not matter if the CSS is via a style element or separate CSS resource.

Without both type and class, the problem is not seen (i.e. with just :not(div), body or :not(.some-class), body as the selector it works as expected).

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[jake]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Bugbug is wrong. Please revert the change. This is a bug with Firefox CSS parsing.

Comment 3

[Emilio Cobos Álvarez [:emilio]]

This was how it was specified back in the day. Bug 933562 updated Firefox to the new spec.