[Bug]: after force closed, and reopening does not collect all previously open tabs.

[whitevamp]

Pre-Submission Checklist

• [X] I have checked the existing/closed issues to ensure this issue has not already been reported.
• [X] I am using the latest supported version of the browser.
• [X] I have tried disabling all browser extensions/add-ons to rule out interference from these.
• [X] I have tried clearing the browser cache and cookies.
• [X] I have checked with a new profile and the issue still occurs.
• [X] I have provided detailed step-by-step instructions on how to reproduce the issue.
• [ ] I have included relevant screenshots or console outputs.
• [X] I have checked that this problem is not occurring in the latest version of Firefox ESR.
• [X] This issue is specific to this browser and does not occur in other browsers.

Bug Summary

Bug Summary:
When the browser is forced to close via Task Manager with a large number of tabs open, reopening it causes tabs to reset unexpectedly. Instead of restoring all previously open tabs, the browser opens only the home page on some or all tabs.

Steps to Reproduce:

1. Open the browser.
2. Open around 25 tabs.
3. Repeat step #two about 15 times (to reach a high tab count).
4. Open Task Manager and force close the browser.
5. Reopen the browser.

Expected Behavior:
All previously open tabs should be restored to their previous pages.

Actual Behavior:
Some or all tabs open to the home page instead of their previous pages, with many tabs missing entirely.

Notes:

• The issue only occurs with a large number of tabs, though the exact threshold is unclear.
• Tested on the latest Firefox version; previous versions did not exhibit this issue.

Reproduction Steps

1. open browser.
2. open, say, about 25 tabs.
3. repeat step #two say about 15 more times.
4. now open task manager, now close browser.
5. now reopen browser. (it does not matter how long you wait to reopen the browser.)
6. now notice some of the tabs are sitting at the home page and not where they were at previously, and that all the tabs are now gone, and only the home page is present. IE: if you had 25 tabs open, only the home page is there now, and none of the tabs.
7. NOTE: I have not nailed down how meany tabs and browser windows it takes to reproduce this issue. I just know it's quite a few. (yes, I usually have a metric tone of tabs and windows open at once.)
8. NOTE: I have the latest version of FF and this behavior is not present, including previous versions.

Expected Behavior

All previously open tabs should be restored to their previous pages.

Actual Behavior

Some or all tabs open to the home page instead of their previous pages, with many tabs missing entirely.

Screenshots

na

Browser Version

11.20.0 (64-bit)

Operating System

23H2 (22631.4317)

Additional Context

Notes:

• The issue only occurs with a large number of tabs, though the exact threshold is unclear.
• Tested on the latest Firefox version; previous versions did not exhibit this issue.

[CutterKnife]

You said you tested with the latest version of Firefox, does the same problem occur with ESR128?

[whitevamp]

You said you tested with the latest version of Firefox, does the same problem occur with ESR128?

not sure on that ver. will see about getting it downloaded and testing it out.

[whitevamp]

You said you tested with the latest version of Firefox, does the same problem occur with ESR128?

not sure on that ver. will see about getting it downloaded and testing it out.

Ok, just downloaded FF ESR128 and installed it, and did some testing with it, and here's what I had figured out.

1. works @ 5 windows with 58 tabs each. 290 tabs total.
2. works @ 10 windows with 58 tabs each. 580 tabs total.
3. works @15 windows with 58 tabs each. 870 tabs total.
4. works @20 windows with 58 tabs each. 1160 tabs total.
5. works @25 windows with 58 tabs each. 1470 tabs total.
6. it all worked as one would expect.
7. stopped where I did because that's way beyond what I normally have opened.
8. with FF no matter the version, it will always show, the restore session tab, but with Floorp, it does not show this tab and just opens all the tabs, back up. (or at least tries to.)

[whitevamp]

For Floorp 11.20.0 (64-bit) : After doing a bit more testing, I have figured out that after 5 windows open with 58 tabs in each window, it will not open any more tabs that were previously opened up. If I open the 6th window with 58 tabs, then it just opens the home page on that 6th and each window after that. I also noticed that Floorp seams to be using More CPU usage, and memory then FF 128.4.0esr (64-bit) : with the same tabs opened up. I forgot to get a screenshot of that usage, while I was testing things out, if you need that screenshot let me know. Also noticed another bug as well, will post a new bug report about that one.

EDITED: added a missing word.