1707930 - Category button gradients are broken when scrolling the Youtube category bar.

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Alice0775 White]

Attachment: screenshot

From Bug 1707456 comment #3

Steps to reproduce:

1. Open https://www.youtube.com/
2. Scroll the category bar (Click < or > button at the right side of the category bar)

Actual Results:
Category button gradients are broken

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=2174903818ae542d463979cd70134789e4ffdc80&tochange=f733b37f9626548ae83564a3fd43ddfa972977d9

Suspect: Bug 1702638 and Bug 1702228

Additional info:
Bug 1707460 (autoland change set d789290b3a2b) did not fix this problem.

Comment 2

[Nicolas Silva [:nical]]

Attachment: Bug 1707930 - Account for reversed stops in the gradient cache key. r=#gfx-reviewers

WebRender internally reverses gradient stops when they are ordered from right to left. This is done while building the GPU data and the gradient cache key stored the reversed stops without sepcifying if they were revered or originally in that order. This meant that if a page had two similar gradients with the only difference being that on was reversed but not the other, they could end up using the same cache key and one of the two would not be rendered properly.

This patch includes a boolean in the cache key to make sure reversed gradients don't accidentally use the same key as similar non-reversed gradients.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5f829807fded
Account for reversed stops in the gradient cache key. r=gfx-reviewers,lsalzman

Comment 4

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/5f829807fded

Comment 5

[Maria Berlinger [:mberlinger], Fxa/Subplat]

Hello,
I’ve managed to reproduce this issue using Firefox 90.0a1 (2021-04-27) on Ubuntu 20.04x64 by following the STR from Comment 0.
This is verified fixed using Firefox 90.0b4 on the following OSes: Windows 10x64, Ubuntu 20.04x64 and macOS 11.3.