1921777 - Setting `display: none` on ::backdrop does not remove it

Status: NEW

(Core :: Web Painting, defect)

Description

[random_n0body]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:131.0) Gecko/20100101 Firefox/131.0

Steps to reproduce:

1. Visit https://codepen.io/depict_daniel/pen/OJKyoMY
2. Click "toggle backdrop visibility"

Actual results:

The backdrop gets more transparent but the background is still faded out

Expected results:

The backdrop gets removed entirely, as it does in both safari and chrome

Comment 1

[random_n0body]

Possible duplicate of https://bugzilla.mozilla.org/show_bug.cgi?id=1836560 But that one seems to be about a test failure and abandoned, thought I'd report this as this actually presents an issue on our website/app

Comment 2

[Francesco Lodolo [:flod] (OOO July 12–20)]

Not sure if this belongs in CSS Parsing and Computation. Please move if there's a better component.

Comment 3

[Boris Chiou [:boris]]

Attachment: testcase

I removed all stuff related to transitions (to make sure this is not related to the display:none animation), and this is still reproducible.

I expect this is a bug related to ::backdrop implementation with display:none.

Comment 4

[Boris Chiou [:boris]]

I set Web Painting based on Bug 1064843.
Please feel free to move back to layout if this is not belonging to Web Painting.

Comment 5

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

The severity field is not set for this bug.
:tnikkel, could you have a look please?

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