1939518 - Hairline doesn't move in vertical tab groups when moving tabs

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect, P1)

Description

[Amy Lee [:amylee] UX]

Attachment: Vertica tab group.mov

Steps to reproduce [can add screenshots or video recordings for reference]:

1. Enable vertical tabs
2. Create a tab group
3. Drag an ungrouped tab that is above or below the tab group

Expected behavior [What should have happened?]:
Tab group repositions as you drag a tab past the opened tab group

Actual behavior [What actually happened?]:

Tab label and tabs shift but hairline is fixed in place

Comment 1

[Dão Gottwald [:dao]]

Attachment: Bug 1939518 - Reimplement vertical tab group line to be more consistent with horizontal tabs, and move container tab line to the end of the tab. r?jswinarton,sthompson,dwalker

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a741f9b130df
Reimplement vertical tab group line to be more consistent with horizontal tabs, and move container tab line to the end of the tab. r=sthompson,tabbrowser-reviewers

Comment 4

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/a741f9b130df

Comment 5

[Dianna Smith [:diannaS]]

Hi Dao! There are three regressions for this bug. Should we back this out of beta for 138 or are those bugs going to be prioritized so that we can uplift them? Please advise.

Comment 6

[Daniel Bodea [:danibodea]]

It appears that the regressions have been fixed and verified and the current report was fixed as well so the NI can be removed.

Furthermore, I can reproduce this issue in Nightly v138.0a1 from 2025-03-27 and I can confirm the fix in Nightrly v138.0a1 from 2025-03-29, Nightly v139.0a1 from 2024-04-24 and Beta v138.0 (RC). The "hairline" (the colored line/segment that determines which tabs are included in the group) is now dynamic when a user drags an ungrouped tab over the grouped tabs. Verified in Windows 10, MacOS 11 and Ubuntu 22.