1915796 - Revamped sidebar borders have become transparent with the System theme on Linux

Status: RESOLVED DUPLICATE of bug 1916004

(Firefox :: Sidebar, defect)

Description

[Kestrel]

Attachment: Transparent borders showing through to wallpaper with System theme on Ubuntu

STR:

1. Start with sidebar.revamp = true on Ubuntu 24.04.
2. Make sure the theme is set to "System theme" and the bookmarks toolbar is disabled.
3. Drag the window around and observe the page content borders.

The sidebar and top page border are transparent, showing the desktop behind the window.

Does not occur with the Light or Dark theme. The Alpenglow theme is also affected.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=112e5d8b6171cd6a545a51a759d04241ab2cd07c&tochange=0164bfc092727658b3d329a2b416dd1bb19c56b9

Regressed by Bug 1915306.

Comment 1

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

Set release status flags based on info from the regressing bug 1915306

:nsharpley, since you are the author of the regressor, bug 1915306, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Nikki Sharpley (:nikkis) (she/her)]

Attachment: WIP: Bug 1915796 - Revamped sidebar borders have become transparent with the System theme on Linux r=#sidebar-reviewers

I've updated the fallbacks to not have a transparency, based on the spec:
https://www.figma.com/design/ZFavpnAJee39j2mFf8U3D0/Sidebar-UX-Spec?node-id=10888-147899&node-type=FRAME&t=RT4VHtPdvI582HjL-0

Comment 3

[Kestrel]

Fixed by Bug 1916004.