1704172 - Flickering window when multiple firefox windows are opened

Status: RESOLVED INCOMPLETE

(Core :: Graphics: WebRender, defect, P3)

Description

[Simon S]

Attachment: Here you can see the flickering during a WebGL game (I see 2 flickers)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0

Steps to reproduce:

1. Open Firefox (window 1)
2. Open at least two tabs
3. Drag one tab out to a second screen to create a second window (window 2)
4. Start some type of video (e.g. on YouTube; embedded WebGL games also cause the bug to happen) in both windows (They don't have to be the same video or be on the same platform).

Actual results:

The video/game in window 1 should now start flickering somewhat. It looks like small screen elements of window 1 appear very shortly randomly in window 1.

I attached a video where you can see the flickering during a WegGL game. But it happens on vidos too which is very distracting. You can pause the video and look how these "flickers" look like.

Sometimes it happens very frequently (many times a second), other times fthe flickering happens more rarely. Try changing the focus between window 1 and 2 if the flickering doesn't seem to start.

Expected results:

It should not flicker.

Comment 1

[Simon S]

The flickering just happend on a single tab in a single Firefox window. I have not yet seen that happen before. I can only reliably get the flickering to happen with the "two-window-technique".

Comment 2

[Simon S]

It also happens with no theme and no add-ons enabled. But it doesn't seem to happen when Firefox is started in safe mode.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Canvas: WebGL' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 4

[Andrei Purice]

Hey Simon,
I tried reproducing this issue on the latest versions of Firefox Nightly 99.0a1 (2022-03-07) , beta 98.0 and release 97.0.2 but it works for me.

Could you try testing with a fresh new profile? You can find more about creating a new profile here : https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems#w_6-create-a-new-firefox-profile .

Comment 5

[Sotaro Ikeda [:sotaro]]

The problem looks similar to Bug 1638709.

Hi Simon, can you attach about:support to this bug? Thank you.

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

A needinfo is requested from the reporter, however, the reporter is inactive on Bugzilla. Given that the bug is still UNCONFIRMED, closing the bug as incomplete.

For more information, please visit BugBot documentation.