Found in

• Firefox 108.0b2

Affected versions

• Firefox 108.0b2
• Nightly 109.0a1
• Firefox 107.0

Tested platforms

• Windows 10
• macOS13 Ventura
• Ubuntu 22.04

Preconditions

• Firefox installed

Steps to reproduce

1. Launch Firefox
2. Open several windows with tabs
3. Load in each tabs some random websites
4. Go to about:support
5. Click on "Refresh Firefox..." button and again "Refresh Firefox" in the pop-up that appears on screen
6. On the Success page, select "Restore only the ones you want"

Expected result

• Under "Restore only the ones you want" there should be the previous opened windows and corresponding tabs.

Actual result

• Under "Restore only the ones you want" no previous windows and tabs are displayed.

Regression range

I checked manually the regression for this issue and noticed that the first affected Nightly build is from 17-10-2022 while the issue can not be reproduced in the previous build from 16-10-2022.
We searched through the pushlogs from this time range and a possible culprit might be Bug 1169529.
Maybe this might help when looking into this.

• Potentially regressed by: https://bugzilla.mozilla.org/show_bug.cgi?id=1169529

:epopescu, if you think that's a regression, could you try to find a regression range using for example mozregression?

:itiel_yn8, since you are the author of the regressor, bug 1169529, could you take a look?

For more information, please visit auto_nag documentation.

Backed out for causing failures on browser_aboutSessionRestore.js

• backout: https://hg.mozilla.org/integration/autoland/rev/8fbf049af8e1c8df65ce825ddcd07d69129cdc75
• push: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&revision=5998b7a73bd9f458695b9a8e02290ffddd188e88&selectedTaskRun=MvUNImcGTveVDzz5mvRV2w.0
• failure log: https://treeherder.mozilla.org/logviewer?job_id=397786475&repo=autoland&lineNumber=2945

20:09:02 INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_590563.js | Uncaught exception in test - undefined - threw exception: TypeError: Window.getComputedStyle: Argument 1 is not an object.
20:09:45 INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_aboutSessionRestore.js | Uncaught exception in test - at chrome://mochitests/content/browser/browser/components/sessionstore/test/browser_aboutSessionRestore.js:31 - TypeError: can't access property "isContainer", view is null
20:09:46 INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_aboutSessionRestore.js | Found an unexpected tab at the end of test run: about:sessionrestore -

Backed out for causing bc failures on browser_aboutSessionRestore.js.

Push with failures

Failure log

Backout link

[task 2022-11-29T18:53:43.711Z] 18:53:43     INFO - TEST-START | browser/components/sessionstore/test/browser_aboutSessionRestore.js
[task 2022-11-29T18:53:43.764Z] 18:53:43     INFO - TEST-INFO | started process screencapture
[task 2022-11-29T18:53:43.888Z] 18:53:43     INFO - TEST-INFO | screencapture: exit 0
[task 2022-11-29T18:53:43.888Z] 18:53:43     INFO - Buffered messages logged at 18:53:43
[task 2022-11-29T18:53:43.888Z] 18:53:43     INFO - Entering test bound 
[task 2022-11-29T18:53:43.889Z] 18:53:43     INFO - TEST-PASS | browser/components/sessionstore/test/browser_aboutSessionRestore.js | we have more than one tab - 
[task 2022-11-29T18:53:43.889Z] 18:53:43     INFO - Buffered messages finished
[task 2022-11-29T18:53:43.890Z] 18:53:43     INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_aboutSessionRestore.js | Uncaught exception in test - at chrome://mochitests/content/browser/browser/components/sessionstore/test/browser_aboutSessionRestore.js:31 - TypeError: can't access property "isContainer", view is null
[task 2022-11-29T18:53:43.890Z] 18:53:43     INFO - Stack trace:
[task 2022-11-29T18:53:43.890Z] 18:53:43     INFO - @chrome://mochitests/content/browser/browser/components/sessionstore/test/browser_aboutSessionRestore.js:31:3
[task 2022-11-29T18:53:43.891Z] 18:53:43     INFO - Leaving test bound 
[task 2022-11-29T18:53:44.216Z] 18:53:44     INFO - GECKO(2230) | MEMORY STAT | vsize 16549MB | residentFast 519MB | heapAllocated 140MB
[task 2022-11-29T18:53:44.217Z] 18:53:44     INFO - TEST-OK | browser/components/sessionstore/test/browser_aboutSessionRestore.js | took 506ms
[task 2022-11-29T18:53:44.218Z] 18:53:44     INFO - Not taking screenshot here: see the one that was previously logged
[task 2022-11-29T18:53:44.218Z] 18:53:44     INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_aboutSessionRestore.js | Found an unexpected tab at the end of test run: about:sessionrestore - 
[task 2022-11-29T18:53:44.229Z] 18:53:44     INFO - checking window state
[task 2022-11-29T18:53:44.236Z] 18:53:44     INFO - TEST-START | browser/components/sessionstore/test/browser_async_duplicate_tab.js

https://hg.mozilla.org/mozilla-central/rev/39352facd261

The patch landed in nightly and beta is affected.
:itiel_yn8, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox108 to wontfix.

For more information, please visit auto_nag documentation.

[Tracking Requested - why for this release]:
This regression has a data-loss impact, when users refresh the profile via about:support.

I would want to request uplift for this but I don't feel confident about the safety of the patch without some QE testing, but this could take a while.
OTOH, this patch alone is a pure improvement over the status quo...
Gijs, what do you think?

(moving tracking request to 108 given that this is about uplifts)

(In reply to Itiel from comment #11)

This regression has a data-loss impact, when users refresh the profile via about:support.

I would want to request uplift for this but I don't feel confident about the safety of the patch without some QE testing, but this could take a while.
OTOH, this patch alone is a pure improvement over the status quo...
Gijs, what do you think?

I feel similarly. Unfortunately we're out of betas - https://whattrainisitnow.com/release/?version=beta .

The patch reorganizes enough that it's not entirely risk-free. Is there a more minimal fix we could apply for beta/rc/108?

The best I can think of is to add this to aboutWelcomeBack.css:

.container.restore-chosen {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  justify-content: center;
}

... but I don't have mozilla-unified set up over here to make a patch and it could take a while until it does...

Is a revert of https://hg.mozilla.org/mozilla-central/rev/72161d401731 for 108 an option otherwise?

(In reply to Ryan VanderMeulen [:RyanVM] from comment #14)

Is a revert of https://hg.mozilla.org/mozilla-central/rev/72161d401731 for 108 an option otherwise?

Yes.

Fixed on 108 by backing out the regressor: https://hg.mozilla.org/releases/mozilla-beta/rev/d49c937bc2e046430bb9468a57ad5151b49bd8ed

I have reproduced this issue using Firefox 108.0b2 on Win 10 x64.
I can confirm this issue is fixed, I verified using Firefox 108.0.1, Fx 109.0.1 and on Fx 110.0 on Win 10, macOS 12 and Ubuntu 22.