2019872 - Kaiser loading indicator (spinning circle) renders with graphical artifacts

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:

1. Load attached testcase (which appears briefly while https://mydoctor.kaiserpermanente.org/ncal/home/ is loading)

EXPECTED RESULTS:
Spinning circle.

ACTUAL RESULTS:
Graphical artifacts.

This regressed in the past few days. Regression range:
https://hg-edge.mozilla.org/integration/autoland/pushloghtml?fromchange=35a31279ee5330be6dd6cafe47bfb60e85f04e6d&tochange=3d8bc17e5a132d0615371d688e5360feafd37dd9

The element is a linear-gradient (background-image: linear-gradient(to right, #90CEF1, #94DFFF 40%, white 100%);) with a transform animation applied (_ngcontent-rbh-c30_rotate which is just to { transform: rotate(360deg); }) So I'm guessing the regression might be from
https://hg-edge.mozilla.org/integration/autoland/rev/669d87301401775275e7f7250ab0dbe1132f15ff

Bug 1978773 - Enable precise linear gradients (GPU-only). r=gfx-reviewers,lsalzman

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: about:support, Graphics section

I'm using Nightly 150.0a1 (2026-02-26) (64-bit) on Ubuntu 25.10.

I've attached my about:support "graphics" section in case that's needed.

Comment 3

[Daniel Holbert [:dholbert]]

I can reproduce in Nightly on macOS as well. (Haven't tested Windows yet, but I'm guessing it'll repro there too.)

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: screencast showing the bug in the wild at Kaiser website (with network throttling applied to make the throbber show for a little bit longer)

Comment 5

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1978773

Comment 6

[Nicolas Silva [:nical]]

Attachment: Bug 2019872 - Prevent (cached) indirect quads from accidentally showing previous contents of the target. r=gw

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/8d9792eaf080
https://hg.mozilla.org/integration/autoland/rev/d08c2c60a5b4
Prevent (cached) indirect quads from accidentally showing previous contents of the target. r=gw

Comment 8

[Silaghi Andreea]

https://hg.mozilla.org/mozilla-central/rev/d08c2c60a5b4

Comment 10

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Reproducible on a 2026-02-26 Firefox Nightly build on Windows 10.

Verified as fixed on Firefox Nightly 151.0a1 and Firefox 150.0b1 on Windows 10, Ubuntu 22, macOS 15.