1779448 - Part of the page is not displayed for a while when scrolling in Settings

Status: NEW

(Core :: Graphics: WebRender, defect)

Description

[tgn-ff]

Attachment: bug_screen_recording.webm

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:104.0) Gecko/20100101 Firefox/104.0

Steps to reproduce:

1. Create a new profile. (The bug is sensitive to the selected preferences.)
2. Open about:preferences#privacy.
3. Make sure that Total Cookie Protection (TCP) is enabled by default in the Standard mode, which should display some explanatory text in the Settings.
4. Set a Primary Password.
5. Go to the top of the (settings>privacy) page and scroll down until the DNT setting are on top of your screen, then up. Repeat until you reproduce the bug.

Actual results:

See the attached video.

The size of the rectangle of missing content depends on the gfx.webrender.picture-tile-* preferences.

This was reproduced on Linux and W11.

Expected results:

Because the issue depends on what is displayed and selected in Settings, mozregression just points to Bug 1774739 which added the TCP text.

Comment 1

[Timothy Nikkel (:tnikkel)]

I can reproduce one square on the left about a quarter of the width not painting when scrolling up on mac.

Comment 2

[Timothy Nikkel (:tnikkel)]

It's always at the exact same spot. The text "Nightly blocks the following" is visible, but the background behind it is not drawn, and the text and background above that point is not drawn. So this doesn't feel like a checkerboarding related bug.

Comment 3

[Ashley Hale [:ahale]]

Triage - setting severity to S4, this appears to be an unpleasant UI issue but definitely cosmetic.