Found in

• 109.0a1 (2022-12-08)

Affected versions

• 109.0a1 (2022-12-08)
• 108.0b9

Tested platforms

• Affected platforms: Windows 10x64, Ubuntu 20.04
• Unaffected platforms: macOS 11

Steps to reproduce

1. Open Firefox and https://www.mozilla-anti-tracking.com/test/dfpi/storage_access_api.html.
2. On the latest iFrame to the right scroll down to Storage Access API.
3. Click requestStorageAccess() and allow it.
4. Open the permission panel and observe it the cookies icon.

Expected result

• The icon is not moved after the panel is opened.

Actual result

• The icon is slightly moving after the panel is opened.

Regression range

• Last good revision: 8108291015f4419be14591ead2d59d6235e7e601
  First bad revision: 73dd9b390b9a0712ea44b2345966c54ebc83c492
  Pushlog:
  https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=8108291015f4419be14591ead2d59d6235e7e601&tochange=73dd9b390b9a0712ea44b2345966c54ebc83c492
• Unfortunately I don't know which of the issues is the regressor.

Additional notes

• Attached a screen recording of the issue.
• On Ubuntu the issue is not so visible.

Adding NI since all three bugs in the possible regression range are assigned to :emilio

Those landed in 108, how can it affect 107?

(In reply to Emilio Cobos Álvarez (:emilio) from comment #2)

Those landed in 108, how can it affect 107?

Sorry for the confusion, I mistakenly left that there from my previous bug. I will edit the description. Firefox 107.0.1 is not affected.

I couldn't repro this on Windows unfortunately... This seems rather minor tho, it's probably a WebRender snapping issue or somesuch.

Is this still an issue?

(In reply to Glenn Watson [:gw] from comment #5)

Is this still an issue?

Yes, the issue is still reproducible with Firefox 126.0a1 (2024-04-01).