1975807 - Firefox forgets new tabs that began as new windows

Status: NEW

(Firefox :: Session Restore, defect, P2)

Description

[G.T.B.]

Steps to reproduce:

For over a year, I have had a window full of tabs to YouTube channels, and I open new videos with "Open Link in New Window", then drag the new window into a tab in a kind of "new videos" window; the result is I then have a window with tabs just to new videos, which I can watch back to back without searching for new content. When I restart Firefox, all these tabs would be restored until a recent update (I think the latest update?), when all the windows-that-were-dragged-into-tabs are now forgotten on restart.

1. Make sure "Open previous windows and tabs" is selected.
2. Open a link from a web page with "Open Link in New Window".
3. Open another link from a web page with "Open Link in New Window".
4. Drag the new window from step 3 into a tab of the window from step 2.
5. Repeat steps 3 and 4 as many times as you like.
6. Restart Firefox.

Actual results:

Only the tab from the step 2 link is restored; all the other step 3 and 4 tabs are forgotten!

Expected results:

Firefox should have remembered and restored the actual tabs, regardless of how they came to be in the window.

Comment 1

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

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

Comment 2

[Stephen Thompson [:sthompson]]

Confirmed on macOS by opening a link in a new window and then dragging the tab from the new window back into the original window. After closing Firefox and reopening with a restored session, the tab in question was not present.

Comment 3

[Monica Chiorean]

I was able to reproduce the issue on Win11x64 using Firefox 140.0.4 and steps from description, tab from step3 is not restored. Marking issue as New.