1647932 - WPT failure when backdrop-filter is enabled: willchange-fixedpos-cb-006

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Erik Nordin [:nordzilla]]

Attachment: Expected Behavior Reference

Description

The WPT for willchange-fixedpos-cb-006.html fails when backdrop-filter is enabled.

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Steps to Reproduce

1. Ensure that gfx.webrender.all and layout.css.backdrop-filter.enabled are enabled in about:config (browser restart required if required if you modified gfx.webrender.all)
2. View the test case in WPT live

or run the following command in your local build:

./mach wpt testing/web-platform/tests/css/css-will-change/will-change-fixedpos-cb-006.html --enable-webrender --setpref layout.css.backdrop-filter.enabled=true

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Expected Results
A single green square as depicted by the reference (see attachment html page).

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Actual Results
A green square and a red square.