1969925 - `TabUngrouped` not fired if a tab group moves between windows, and it the group is the only thing on the tab strip

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, defect, P1)

Description

[Jeremy Swinarton (PTO until 2026-04-06)]

STR:

1. Open two windows.
2. In the second window, create a tab group, and remove all other tabs in the window.
3. Drag the tab group into the first window.

Expected result:

• A TabUngrouped and TabGrouped event is fired for each tab in the tab group. This is the current behaviour when there are other tabs in the window (and thus the window does not close when the group is moved).

Actual result:

• Only the TabGrouped events fire and the TabUngrouped events do not fire.

Comment 1

[Jeremy Swinarton (PTO until 2026-04-06)]

Attachment: Bug 1969925: Dispatch TabGrouped when adopting tab group and it is the last thing on the tab strip r?dwalker,sthompson

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d51d008ac7b7
https://hg.mozilla.org/integration/autoland/rev/d3beeb6bbbec
Dispatch TabGrouped when adopting tab group and it is the last thing on the tab strip r=sthompson,tabbrowser-reviewers

Comment 3

[amarc]

https://hg.mozilla.org/mozilla-central/rev/d3beeb6bbbec