2014963 - Dragging a Split View and a normal tab to an existing window will multiselect all the tabs on the left

Status: ASSIGNED

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

Description

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

Attachment: split_4.gif

Found in

• 149.0a1 (2026-02-05)

Affected versions

• 149.0a1 (2025-02-05)

Tested platforms

• Affected platforms: macOS 26, Windows 11, Ubuntu 24
• Unaffected platforms: none

Steps to reproduce

1. Create two windows and a Split View.
2. Open a normal tab and multi-select the Split View with the normal tab.
3. Drag the Split View to another window.

Expected result

• The initial Split View and normal tabs remain selected.

Actual result

• The tabs positioned on the left are selected as part of multiselection, and sometimes the Split View is unselected.

Regression range

• Not a regression. Happens after implementation on multiselection of multiple split views (bug 2003764).

Additional notes

• Attached a screen recording.

Comment 1

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

This will get fixed as part of bug 2014358

Comment 2

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

Attachment: Bug 2014963 - Fix multiselection range when splitview is included r=#tabbrowser-reviewers,sclements