1622549 - canvas linear gradient now works on linux but not on windows

Status: NEW

(Core :: Graphics, defect, P3)

Description

[Dusan Halicky]

Attachment: Demo code

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:74.0) Gecko/20100101 Firefox/74.0

Steps to reproduce:

I want to fill rectangle in HTML canvas using linear gradient from pure black rgba(0,0,0,1) to almost opaque red rgba(255,0,0,0.1). On linux this works but on windows it does not. The gradient is just gray. On chrome it works on both linux and windows so it seems it is not graphical driver issue.

Actual results:

Gray gradient instead of red gradient.

Here is image comparing all browsers: https://ghost.sk/54.png

Expected results:

Gradient should be red.

Comment 1

[Alice0775 White]

I can reproduce the issue on Nightly76.0a1 when HWA ebabled, However, I can not when HWA disabled.

Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=d9515d63a7cf34382ef0f3670084e7b77fa218c0&tochange=f212d89048ecdd6f15006f368322a2d2e156432b

Comment 2

[Miko Mynttinen]

Reproduced on Windows 10 with the latest Nightly, both WebRender enabled and disabled.

Bas, this looks like a regression from your patch for bug 1427063.
It is similar to bug 1509396, but for canvas element. Since the second bug has not changed since 2018, this is probably not urgent. Are there any plans to fix this?

Comment 3

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is P3 (Backlog,) indicating it has been triaged, the bug's Severity is being updated to S3 (normal.)