Moving "other tabs" into current window broke all open windows with tab groups; windows had invisible tabs from other groups

[mlncn]

Describe the bug

(Running into #960 i mistakenly thought the the problem might be in the mysterious list of hidden tabs… and the real trouble began.)

From the Simple Tab Groups toolbar icon dropbown, the "show other tabs" indicated "Found hidden unsynchronized tabs" and a large number, 80+, were there.

From a new, non-group window i choose "Move all of these tabs into the current group/window"

All four open groups get blown up somehow, they are now windows with no tabs at all. And there is still 85 items under "show other tabs". (Not sure how anything got there in the first place; when starting with Simple Tab Groups i chose the close all option. I have tested closing non-group windows and tabs from them do not go to 'other tabs', they are just gone as expected.)

The blanked-out windows persist through quitting and re-starting Firefox.

It appears there are invisible tabs in these blanked-out windows, see attached video.

To Reproduce Steps to reproduce the behavior:

1. Somehow end up with a lot of things in "see other tabs"
2. Have four or more groups open
3. Open a new non-group window
4. Click the STG toolbar icon and select "Move all of these tabs into the current group/window"

Expected behavior

Currently open groups remain working.

Screenshots

The mouse cursor does not show, but all i am doing is closing the one empty tab, hich reveals a secret non-empty tab that very quickly disappears, but if i click fast enough will also close, revealing the next tab:

simple-tab-groups-broken-edited.webm

Looking at these hidden tabs, they belong to groups, groups that were and are currently closed.

But closing the ghost tab here in this non-group window (that has no truly visible tabs) removes the tab from the group. It's all very bad. :frowning_face:

Desktop (please complete the following information):

• Debian GNU/Linux bookworm/sid
• Gnome 42.2 and the Wayland windowing system
• Firefox version: 102.0
• Simple Tab Groups version: 4.7.2.1

Additional context

Is there a way to export my STG configuration?

[mlncn]

Restarted computer and 80 pages that were in "Show other tabs" is gone, but if i open a new (non-group) window i can see for an instant it loading a bunch of tabs, and then when i close the single empty tab it does the momentary appearance of a tab from one of my groups as shown in the video above. Yikes.