1779437 - Google docs paints all black (with bug 1771374)

Status: VERIFIED FIXED

(Core :: Graphics: CanvasWebGL, defect, P1)

Description

[Ryan VanderMeulen [:RyanVM]]

Attachment: screenshot

Annoyingly, this didn't reproduce for me in mozregression unless I used my regular profile for it, but I was eventually able to bisect this to bug 1771374.

Comment 1

[Ryan VanderMeulen [:RyanVM]]

Attachment: relevant about:support info

Comment 2

[Ryan VanderMeulen [:RyanVM]]

Confirmed via local backout that bug 1771374 was the regressor.

Comment 3

[Jens Stutte [:jstutte]]

Attachment: JensAboutSupport.txt

about:support from another affected machine.

Comment 4

[Ryan VanderMeulen [:RyanVM]]

Looks like we're both on nVidia with the latest drivers.

Comment 5

[Ben Dean-Kawamura [:bdk]]

Maybe related: My google docs seems to be one change behind the current state. When I type, the page displays the N-1 change in the document (I type "dog" and see "do"). Clicking outside the document sometimes reveals the latest change.

I'm on Fedora with an nvidia card and the nouveau drivers.

Comment 6

[Ryan VanderMeulen [:RyanVM]]

That's bug 1779410 most likely.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

FWIW, the behavior reproduces already with https://hg.mozilla.org/mozilla-central/rev/ef52a6c462b6.

Comment 8

[Kelsey Gilbert [:jgilbert]]

Workaround: gfx.webrender.dcomp-video-overlay-win:false and restart browser

Testcase: https://jsfiddle.net/gspfr4x2/2/

It looks like alpha!=1.0 pixels from canvas (2d or webgl) with dcomp broke.

Comment 10

[Jens Stutte [:jstutte]]

I can confirm that the workaround works, thanks.

Comment 12

[Kelsey Gilbert [:jgilbert]]

This was fixed by reverting bug 1771374.

Comment 13

[Bogdan Maris, Desktop Test Engineering]

Reproduced the dark background in in Google doc and the dark areas from the demopage from comment 8, verified that using latest Firefox 104.0b5 on Windows 10 (Nvidia GTX1070 TI) the issue is no longer reproducible.