2012314 - When dragging a tab out of window, sometimes the wrong window is focused

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, defect)

Description

[Apples]

Attachment: A video demonstrating the behavior with various other apps

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Steps to reproduce:

• Open a Firefox window
• Drag a tab out of the window to make it its own window
• Release the tab on top of another window

Actual results:

Sometimes the new window that is created is spawned behind the existing window under the cursor when the mouse button was released.

Also, when dragging a tab from a window with multiple tabs, the newly created window appears at the end of the window list in the Alt+Tab menu.

This appears to only happen with Electron apps, but not all Electron apps. I found that this happens with Spotify, GitHub Desktop, Visual Studio Code, and Logseq, but not in Discord or Slack or native apps like Google Chrome, File Explorer, or Paint.

This behavior was observed on Windows 10 22H2 and Windows 11 23H2. Did not appear to happen on macOS Sequoia 15.7.3.

Expected results:

The newly created window is focused.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Tabbed Browser' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.