1964923 - Tab groups still move vertically when using expand on hover with vertical tabs on Windows and Linux

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect, P1)

Description

[patrice.grundmann]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Steps to reproduce:

• Add some tabs in Firefox Nightly
• Add some containers (with Firefox Account Containers add-on)
• Add some tabs in containers created
• Add some tabs groups and put some tab into them

Actual results:

The hover effect since it appear (the 20 march) in Nightly is very disturbing. Visual focus is lost between the favicon (with the tab folded) and its unfolded version, when there's a hover effect on the favicon.

Expected results:

The expected behavior, if there is already the possibility of visually finding one's way around tabs, would be that the display should be identical and persist regardless of whether the tabs are “open” or “closed”. Take a look at Microsoft Edge to see for yourself.

Here is the bug in a image (two screencaps). I have drawn yellow dotted lines to visualise the problem.
Here is the gap example: https://ibb.co/xqBbYrbF
And https://ibb.co/NDDSbNV

The bug is releated to: https://bugzilla.mozilla.org/show_bug.cgi?id=1956394

Comment 1

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

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

Comment 2

[Dão Gottwald [:dao]]

I can reproduce on Linux as well. Might be harder to reproduce on macOS as it likely depends on the system font size.

Comment 3

[Dão Gottwald [:dao]]

Upgrading priority to match bug 1956394.

Comment 4

[Dão Gottwald [:dao]]

Attachment: Bug 1964923 - Make tab group label layout more consistent between collapsed and expanded vertical tabs so that things don't move around vertically when expanding on hover. r?sthompson

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/76e2e0a1877e
Make tab group label layout more consistent between collapsed and expanded vertical tabs so that things don't move around vertically when expanding on hover. r=sthompson,tabbrowser-reviewers

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/76e2e0a1877e

Comment 8

[Rares Doghi, Desktop QA]

This issue is Verified as fixed in our latest Nightly 140.0a1 (2025-05-12)

Comment 9

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

The patch landed in nightly and beta is affected.
:dao, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox139 to wontfix.

For more information, please visit BugBot documentation.

Comment 10

[Rares Doghi, Desktop QA]

Updating the remaining flags.