1817279 - [wpt-sync] Sync PR 38553 - [@scope] Set AffectedBy[Non]SubjectHas for @scope

Status: RESOLVED INVALID

(Core :: CSS Parsing and Computation, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 38553 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/38553
Details from upstream follow.

Anders Hartvoll Ruud <[e-mail]> wrote:

[@scope] Set AffectedBy[Non]SubjectHas for @scope

Invalidation of elements affected by scope selectors would not work
well for :has(), because we'd incorrectly set AffectedBySubjectHas
when we should have set AffectedByNonSubjectHas.

In terms of invalidation, the following:

@scope (.a:has(.c)) {
.b { ... }
}

should invalidate the same way as:

.a:has(.c) .b, .a:has(.c):is(.b)

Therefore we can fix this issue by setting in_rightmost_compound to
true or false depending on if we're matching the original subject
element or not. I.e. we're pretending to not be the rightmost compound
when matching non-subject elements.

Bug: 1280240
Change-Id: I7205924adb83fac405650c095d3edb8f582a054b
Reviewed-on: https://chromium-review.googlesource.com/4261470
WPT-Export-Revision: 810cb192391f84e0bdc0a104d4a9210a6d048e01