1986166 - Visible borders when firefox is first time in fullscreen (error occuring again after it was fixed in the past)

Status: UNCONFIRMED

(Core :: Widget: Win32, defect)

Description

[Milo Wagnitz]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:142.0) Gecko/20100101 Firefox/142.0

Steps to reproduce:

I've opened Firefox and then entered full screen mode (doesn't matter if it's YouTube or a streaming website like Netflix, Paramount, etc.)

Firefox has to be fully closed and then be opened.

Actual results:

When entering full screen mode for the first time after opening Firefox, on the left side and at the top of the screen, there are visible borders where I can see my desktop wallpaper trough.

After leaving full screen and entering again, the error disappears until Firefox is fully closed and then opened again. Then it's occurring again for the first full screen and after that, it's gone.

I've already discovered the error in earlier versions of Firefox on Windows 11 a few years ago. The error was fixed back then but is now occurring again. In the past, it was only happening on Windows 11, not on Windows 10. It was when Windows 11 was new. I'm not sure if it's happening also on Windows 10 because I'm only using Windows 11.

Expected results:

When entering full screen, the full screen should be covered by the video. The wallpaper should not be visible anymore.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Firefox::New Tab Page' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Greg Stoll :gstoll]

If you’re able to reproduce this reliably, running mozregression ( https://mozilla.github.io/mozregression/ ) would help a lot in tracking this down.