2019925 - Using the `Move tab to Split View` option on a Split View that is not in a group will not displaye the Split View as expected

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser: Split View, defect, P1)

Description

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: split_7.gif

Found in

• 149.0b1

Affected versions

• 150.0a1 (2025-01-26)
• 149.0b1

Tested platforms

• Affected platforms: Ubuntu 24, Windows 11, macOS 14
• Unaffected platforms: none

Steps to reproduce

1. Create a Split View with YouTube and Reddit and add it to a group.
2. Outside the group, create another Split View and use move tab to Split View option on Reddit or YouTube.

Expected result

• The Split View is displayed as expected.

Actual result

• The Split View is not displayed as expected.

Regression range

• Not a regression. Happens after implementation of the option (bug 2003892)

Additional notes

• Attached a screen recording.

Comment 1

[Kelly Cochrane [:kcochrane]]

Attachment: Bug 2019925 - Ensure split view tab panels are displayed properly when moving a tab from one split view to another split view

Comment 2

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined: Split view panels may be displayed unexpectedly when moving a tab from one split view to another using the urlbar 'Move tab to split view' action.
• Code covered by automated testing: yes
• Fix verified in Nightly: no
• Needs manual QE test: yes
• Steps to reproduce for manual QE testing: Create a split view
  Right click a tab outside of the split view and select "Add Split View"
  In the urlbar for the new split view, select one of the tabs from the first split view ensuring the "Move tab to split view" indicator is shown for that item in the urlbar results
  Ensure both panels are displayed at roughly 50% width after the tab has moved to the new split view
• Risk associated with taking this patch: low
• Explanation of risk level: 6 line change in tabsplitview.js covered by automated tests
• String changes made/needed: N/A
• Is Android affected?: no

Comment 3

[Kelly Cochrane [:kcochrane]]

Attachment: Bug 2019925 - Ensure split view tab panels are displayed properly when moving a tab from one split view to another split view

Original Revision: https://phabricator.services.mozilla.com/D286149

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/3e5bcbb12ff1
https://hg.mozilla.org/integration/autoland/rev/788374ba3539
Ensure split view tab panels are displayed properly when moving a tab from one split view to another split view r=tabbrowser-reviewers,jsudiaman

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/6aa2db43ecc8
https://hg.mozilla.org/integration/autoland/rev/f7d32736fa46
Revert "Bug 2019925 - Ensure split view tab panels are displayed properly when moving a tab from one split view to another split view r=tabbrowser-reviewers,jsudiaman" for causing failures at browser_switchTab_override.js.

Comment 6

[Atila Butkovits]

Backed out for causing failures at browser_switchTab_override.js.

Backout link: https://hg-edge.mozilla.org/integration/autoland/rev/f7d32736fa460fa96eba8df42fba2938a351e989

Push where failures started: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=f71f4765256fb08f4c4dae597181e79bc182b435&selectedTaskRun=QUx_X0RcS3eZz7KLnP4WxQ.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=551963472&repo=autoland&task=QUx_X0RcS3eZz7KLnP4WxQ.0&lineNumber=8395

Comment 7

[Sarah Clements [:sclements]]

Lets have QA verify this first before uplifting as there are a lot of overlapping changes landing atm.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/256cc51a809f
https://hg.mozilla.org/integration/autoland/rev/4e97fa600829
Ensure split view tab panels are displayed properly when moving a tab from one split view to another split view r=tabbrowser-reviewers,jsudiaman

Comment 9

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/4e97fa600829

Comment 10

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Verified fixed with Firefox 150.0a1 (2026-03-05) on Windows 11, macOS 26 and Ubuntu 24. The Split View is correctly displayed after following the steps from comment 0.

Comment 11

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/11605c945054
https://hg.mozilla.org/releases/mozilla-beta/rev/b4b41f1384a6

Comment 12

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Verified fixed with Firefox 149.0b6 (20260309091903) on Windows 11, macOS 26 and Ubuntu 24. The Split View is correctly displayed after following the steps from comment 0.