1565138 - Aero glass border flickers frequently, when interacting with the browser UI

Status: RESOLVED DUPLICATE of bug 1562184

(Core :: Web Painting, defect)

Description

[Stuart Cook]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:69.0) Gecko/20100101 Firefox/69.0

Steps to reproduce:

• Update to Firefox 69
• Make sure the browser window is not maximised
• Interact with the browser UI (open a tab, switch tabs, hover over a tab, hover over the URL bar, open the menu, etc.)

Actual results:

Part of the window's Aero glass border flickers during the UI interaction, and then stops flickering shortly after.

Expected results:

The Aero glass border should remain stable, and not flicker.

Comment 1

[Stuart Cook]

Attachment: flicker-off.png

Comment 2

[Stuart Cook]

Attachment: flicker-on.png

Comment 3

[Stuart Cook]

The exact effect is hard to describe, but it's very obvious (and disruptive) in practice.

After immediately running into this issue on my main profile, I created a fresh profile and reproduced the issue there as well.

Comment 4

[Stuart Cook]

Turning on gfx.webrender.all (and restarting the browser) seems to get rid of the flashing, and turning it back off (and restarting) restores the flashing.

So there appears to be some kind of problem in the non-WebRender UI painting.

Comment 5

[[:philipp]]

hi, thank you for the report - i think it's the same issue that's getting investigated in bug 1562184, so i'll dupe it over.