2015866 - Users can Drag and Drop a New tab / Homepage from the Smart Window into a Classic Window

Status: VERIFIED FIXED

(Core :: Machine Learning: Frontend, defect, P1)

Description

[Rares Doghi, Desktop QA]

Attachment: DragandDrop.mp4

Found in

• Nightly 149.0a1 (2026-02-10)

Affected versions

• Nightly 149.0a1 (2026-02-10)

Affected platforms

• All

Steps to reproduce

1. Open a new tab in a New Smart Window.
2. Drag that New Tab into a Classic Window.
3. Continue the conversation.

Expected result

• Users should not be able to drag a New Smart Window Tab into a Classic Firefox window.

Actual result

• Users can Drag the Home page tab into a Classic Firefox Window.

Regression range
N/A

Comment 1

[Ed Lee :Mardak]

not necessarily a bug as titled as people can switch from smart to classic with a conversation already but the page should reflect that the conversation needs to be in a smart window

Comment 2

[Giulia Cardieri (:gcardieri)]

Attachment: Bug 2015866: Update smart tab state when it is adopted by a classic window

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/f1a7553b589a
https://hg.mozilla.org/integration/autoland/rev/ce69ad4f40fb
Update smart tab state when it is adopted by a classic window r=ai-frontend-reviewers,pdahiya,yjamora

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/ce69ad4f40fb

Comment 5

[Rares Doghi, Desktop QA]

Verified as fixed in our latest Nightly 151.0a1 (2026-03-24)