av9ash/GitBugs huggingface dataset:
Bug: Address bar retains focused appearance if Unified Search Button had keyboard focus when leaving
Status: VERIFIED
Priority: --
Resolution: FIXED
Created: 2024-11-26 13:31:12+00:00
Resolved: 2024-12-17 13:50:36+00:00

STR:
1. Focus the address bar (Ctrl+L).
2. Type something.
3. Press Shift+Tab to move focus to the Unified Search Button.
4. Click the page content.

Expected:
Address bar no longer has focused appearance.

Actual:
Address bar retains highlighted outline as if it has keyboard focus when it does not.


Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=480c30b779eab3d6ce7237fcbaec69f465f5d053&tochange=d40618764e0c7dbd85ebf103edfb5b602f0bede6

Regressed by Bug 1921174.
Bug: Unified Search Button menu background color does not use theme color like other popup panels
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2024-11-26 13:37:32+00:00
Resolved: 2024-11-27 08:34:20+00:00

STR:
1. Enable the Alpenglow theme.
2. Click the Unified Search Button in the address bar.

Expected:
Search list background is purple like other popup panels.

Actual:
Search list background is dark.
Bug: TPS fails if `identity.fxaccounts.oauth.enabled` is true
Status: NEW
Priority: P2
Created: 2024-11-26 16:25:30+00:00
Resolved: 2024-11-28 06:04:34+00:00

The Firefox iOS sync integration tests could not sync to the stage server starting on Nov 23:

https://storage.googleapis.com/mobile-reports/public/firefox-ios-M1/result_928/firefox-ios/firefox-ios-tests/Tests/SyncIntegrationTests/results/index.html?sort=result

The TPS log indicated that the login has been successful but stop at `CROSSWEAVE INFO: Setting up wait for weave:service:setup-complete...`:
https://storage.googleapis.com/mobile-reports/public/firefox-ios-M1/result_928/firefox-ios/firefox-ios-tests/Tests/SyncIntegrationTests/results/assets/test_integration.py__test_sync_bookmark_from_desktop_1_0.txt

This is the TPS log for the same test during last known successful test run:
https://storage.googleapis.com/mobile-reports/public/firefox-ios-M1/result_927/firefox-ios/firefox-ios-tests/Tests/SyncIntegrationTests/results/assets/test_integration.py__test_sync_bookmark_from_desktop_3_0.txt

The source code for sync integration tests is found here: https://github.com/mozilla-mobile/firefox-ios/tree/main/firefox-ios/firefox-ios-tests/Tests/SyncIntegrationTests. The test_*.js files are the `profiles` used in FirefoxRunner (see tps.py https://github.com/mozilla-mobile/firefox-ios/blob/main/firefox-ios/firefox-ios-tests/Tests/SyncIntegrationTests/tps.py#L36). The content of the `profiles` are supposed to be synced with the stage Mozilla Accounts server.
Bug: List all tabs button re-appears by itself
Status: NEW
Priority: P3
Created: 2024-11-26 17:44:55+00:00
Resolved: 2025-02-21 11:21:39+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

Remove the "List all tabs" button by right clicking, remove from toolbar

I'm using the latest Firefox Flatpack (133.0) on the latest KDE Neon (6.2.3)


Actual results:

List all tabs button is removed from toolbar, but after awhile it re-appears. I'm unable to figure out exactly when this happens (it doesn't seem to consistently happen after restarting Firefox or the device, or even after updates), but since the ability to remove the button was added a little over a month ago - https://bugzilla.mozilla.org/show_bug.cgi?id=1918681 - I've had the button re-appear for me around 20 times, each time removing it again.


Expected results:

List all tabs button does not re-add itself to the toolbar
Bug: [Section Expt] Card UI tweaks v2.0
Status: RESOLVED
Priority: --
Resolution: FIXED
Created: 2024-11-26 18:26:52+00:00
Resolved: 2024-11-28 15:23:20+00:00

Notes from meeting with Tati and Bryan:

- Large Card
    - 220 x 220 px
- Smaller space between publisher and title
- reducing size of small images to 120x120 px
Bug: Firefox opens a new tab along with remembered pinned tabs
Status: RESOLVED
Priority: --
Resolution: WONTFIX
Created: 2024-11-26 19:36:10+00:00
Resolved: 2024-11-26 19:58:08+00:00

Steps to reproduce:

* Make sure `Open previous windows and tabs` is enabled in your settings
* Pin two tabs
* Restart Firefox


Actual results:

Firefox opens a new tab along with your remembered pinned tabs.


Expected results:

It should open only your pinned tabs.
Bug: NimbusTelemetry feature does not shut off metrics upon experiment end
Status: RESOLVED
Priority: P1
Resolution: FIXED
Created: 2024-11-26 22:10:39+00:00
Resolved: 2024-12-13 09:45:36+00:00

When an experiment ends, the NimbusTelemetry feature will call [Services.fog.applyServerKnobsConfig with an empty payload](https://searchfox.org/mozilla-central/rev/dfaf02d68a7cb018b6cad7e189f450352e2cde04/toolkit/components/nimbus/lib/ExperimentManager.sys.mjs#2210), but that does not disable the metrics that would have been turned on in that feature.

We should have a defaults object that we merge the feature value into and then call into fog with that value so that metrics are properly reset upon experiment end.
Bug: Hide the sidebar if its button is removed from the toolbar
Status: VERIFIED
Priority: P2
Resolution: FIXED
Created: 2024-11-26 22:52:27+00:00
Resolved: 2025-01-13 13:32:55+00:00

**User story**
As a user, I want to be able to remove the sidebar with one click if I do not need it. 

**Current result**
If a user removes the sidebar button when the sidebar is set to the expanded state, they cannot get rid of it until:
- they return the sidebar button through the *Customize toolbar* menu, 
- collapse the sidebar, 
- remove the button from the toolbar via the right-click one more time. 

**Acceptance criteria**
1. The sidebar is hidden from view entirely (no collapsed or expanded state is visible on the screen) once a user removes the sidebar button from the toolbar.
Bug: Sidebar can't be disabled
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2024-11-27 01:14:51+00:00
Resolved: 2024-11-27 09:56:45+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

I opened my firefox and now i see sidebar, but i can't disable it, console give me so much errors


Actual results:

So much errors: Uncaught (in promise) TypeError: this.contextMenuTarget is null
    removeExtension chrome://browser/content/sidebar/sidebar-main.mjs:153
    handleEvent chrome://browser/content/sidebar/sidebar-main.mjs:212



Expected results:

No more sidebar, cuz it's so annoying
Bug: Fix bad test testRecentlyClosedTabGroupsSingleTab
Status: RESOLVED
Priority: P1
Resolution: FIXED
Created: 2024-11-27 02:39:06+00:00
Resolved: 2024-11-27 16:54:50+00:00

bug 1834559 showed an uptick in failures after merging bug 1927774

The test failure is `browser/components/customizableui/test/browser_history_recently_closed.js | Opened the first URL - Got "about:logo", expected "about:mozilla"`

This is from a new test that I wrote and added in that patch. The test is not a good test because it closes a tab group with two tabs and then uses the recently closed tabs menu to reopen whichever tab is listed first inside of the closed tab group. Since the tabs inside the group are closed at the same time, I think it's possible for either tab to be listed first in the menu.

The test needs to set expectation(s) that are stable across all test runs.
Bug: When I drag and drop a pdf file from my explorer to firefox, it opens a completely different image from the cache
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2024-11-27 10:29:29+00:00
Resolved: 2024-12-20 10:28:34+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:132.0) Gecko/20100101 Firefox/132.0

Steps to reproduce:

Opened Firefox, opened the Dolphin explorer, dragged and dropped a pdf file generated by Google Docs into a tab.


Actual results:

An image that appeared while I was looking for a different one yesterday on a DuckDuckGo search appeared on the tab (same as when you click to "open in a new tab"). I did not save this image anywhere in my computer and did not have it open at the time the bug happened, I assume it was in my browser's cache.


Expected results:

I'm not sure what is the expected behavior, I would assume it's opening the pdf file. At the time the bug happened I was trying to send the file through moodle, but it wasn't recognizing it.
Bug: www.youtube.com - The tooltip bar stays open when opening a video
Status: NEW
Priority: --
Created: 2024-11-27 11:04:31+00:00
Resolved: 2025-01-10 19:51:46+00:00

**Environment:**
Operating system: Windows 10
Firefox version: Firefox 132.0

**Steps to reproduce:**
1. Navigate to: https://www.youtube.com/watch?v=dbjPnXaacAU
2. Play the video and observe the bottom of the page

**Expected Behavior:**
The tooltip bar hides

**Actual Behavior:**
The tooltip bar stays open

**Notes:**
- Reproduces regardless of the status of ETP
- Reproduces in firefox-nightly, and firefox-release
- Does not reproduce in chrome
- Hovering over the link or over videos seems to fix the issue

Created from https://github.com/webcompat/web-bugs/issues/144325
Bug: Este es un problema de prueba (This is a test bug, will close when completed testing)
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2024-11-27 11:41:30+00:00
Resolved: 2024-11-27 12:43:25+00:00

El artículo, en morfología lingüística, es un tipo de determinante actualizador, una categoría morfológica que emplean algunas lenguas para actualizar o precisar la referencia de un sustantivo, transformándolo de desconocido y abstracto («un libro») a conocido y concreto («el libro»). Es un indicador que sitúa lo que se dice en el contexto común al que lo dice y al que lo oye, o sea, en el mutuo acuerdo de los interlocutores.1​

En gramática tradicional, se llama artículo tanto a los determinantes definidos como al determinante indefinido relacionado con el significado de '1'. En gramática generativa en general se considera que el artículo es el núcleo sintáctico del sintagma determinante.
Bug: Since the last update I always have a page from mozilla that opens to ask for a donation, it's very unpleasant!
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2024-11-27 14:11:14+00:00
Resolved: 2024-12-18 13:03:18+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

Just applied the last update


Actual results:

 I always have a page from mozilla that opens to ask for a donation


Expected results:

Don't have this very unpleasant page to appear!
Bug: [Experiment] The “Show less frequently” cap cannot be reached after the feature is enabled and the browser is NOT restarted
Status: NEW
Priority: P3
Created: 2024-11-27 14:11:17+00:00
Resolved: 2024-11-28 01:06:45+00:00

**[Notes:]**
- The issue is also reproducible with the Weather results. 
- The issue is NOT reproducible if the browser is restarted after the feature is enabled.

**[Affected versions]:**
- Firefox Beta 134.0b1 - Build ID: 20241125200000 (changed channel in Release)
- Firefox Nightly 135.0a1 - Build ID: 20241127095617 


**[Affected Platforms]:**
- Windows 11 x64
- macOS Sequoia 15.0.1
- Ubuntu 22.04 x64


**[Prerequisites]:**
Have following prefs set:
- browser.search.region = US
- browser.urlbar.yelp.mlEnabled = true
- browser.urlbar.quicksuggest.mlEnabled = true
- browser.ml.enable = true

**[Steps to reproduce]:**
1. Open the browser using the profile from the prerequisites.
2. Open a new tab and trigger an ML Yelp result (eg: build).
3. Click the Feedback menu button and click the "Show less frequently" option.
4. Dismiss and focus on the address bar.
5. Type one more character to the typed keyword (e.g. "build + space").
6. Click the Feedback menu button and click the "Show less frequently" option.
7. Dismiss and focus on the address bar.
8. Type one more character to the typed keyword (e.g. "buildi").
9. Click the Feedback menu button and click the "Show less frequently" option.
10. Dismiss and focus on the address bar.
11. Type one more character to the typed keyword (e.g. "buildin").
12. Click on the “Feedback” button and observe the options.


**[Expected result]:**
-  The “Show less frequently” option doesn’t appear if the cap has been reached.

**[Actual result]:**
- The “Show less frequently” option appears even if the cap has been reached.

**[Additional Notes]:**
- A video of this issue is attached [here](https://drive.google.com/file/d/1kd3Bj-htjcdli8tPlxeXnYxYKDpcUaZv/view?usp=drive_link).
Bug: When a link is dragged onto the History menu in the menubar, the History menu opens
Status: VERIFIED
Priority: --
Resolution: DUPLICATE
Created: 2024-11-27 17:44:24+00:00
Resolved: 2025-01-16 01:57:43+00:00

Steps to reproduce:
1. Enable menubar
2. Open any web page
3. Drag a link onto History menu on menubar

Actual results:
The History menu will open

Expected results:
Nothing happens.
Mouse cursor should indicate as 'not-allowed'

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=1631a4d2ffc43099bb6e9ae202667fb97a4aaebe&tochange=dbca11d5cd9149d05b62400ac3821b64641cd0cf
Bug: When a link is dragged onto the  menu(File Edit View.... ) except Bookmarks in the menubar,  Mouse pointer should be changed to 'not-allowed'
Status: VERIFIED
Priority: P3
Resolution: FIXED
Created: 2024-11-27 17:56:06+00:00
Resolved: 2024-12-04 14:54:37+00:00

Steps to reproduce:
1. Enable menubar
2. Open any web page
3. Drag a link onto menu such as File Edit View... except Bookmarks on menubar

Actual results:
Mouse cursor indicates as 'default'(arrow)

Expected results:
Mouse cursor should indicate as 'not-allowed'

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=1631a4d2ffc43099bb6e9ae202667fb97a4aaebe&tochange=dbca11d5cd9149d05b62400ac3821b64641cd0cf
Bug: Inconsistent sidebar button background between "Show and hide sidebar" and "Expand and collapse sidebar" when panel is open.
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2024-11-27 20:18:08+00:00
Resolved: 2024-11-27 21:07:53+00:00

:danibodeo wrote in bug 1914452:
> When the Sidebar button is set to "Show and hide sidebar" and the user clicks the "Show sidebar" button in order to open it, he will notice that the button's background does not change to a darker one to show that the sidebar is opened. This behavior is not observed in Nightly v133.0a1 (2024-10-02) with the old icon. This issue does not occur if the Sidebar button is set to "Expand and collapse sidebar".

I don't think this is a regression caused by bug 1914452 but rather related to state management intricacies. Its possible this will be resolved with the introduction of a state api in Bug 1930199. :jsudiaman, do you know if this is the case?
Bug: "Close other tabs" should save and close groups, including collpased groups
Status: RESOLVED
Priority: P2
Resolution: FIXED
Created: 2024-11-27 20:47:57+00:00
Resolved: 2025-01-27 13:07:40+00:00

**Steps to reproduce [can add screenshots or video recordings for reference]:**

1. Create a tab group with several tabs inside it
2. Collapse the tab group
3. Open several ungrouped tabs
4. Right-click on an ungrouped tab and select "Close all other tabs" from the context menu

**Expected behavior [What should have happened?]:**

The collapsed tab group disappears along with all other tabs

**Actual behavior [What actually happened?]:**

All ungrouped tabs close but the collapsed tab group stays opened

See video for reference https://drive.google.com/file/d/1M8Az4oXB5v5pv3m69aziCFOD3ydWOmLu/view?usp=drive_link
Bug: With Show/Hide set, Ctrl+B and Ctrl+H should hide rather than collapse the sidebar
Status: RESOLVED
Priority: P2
Resolution: FIXED
Created: 2024-11-27 21:13:02+00:00
Resolved: 2024-12-14 10:00:50+00:00

For keyboard-oriented users, it is very inconvenient to change from toggling show/hide with a keyboard shortcut to being required to use a toolbar button to close the sidebar. If the user has changed from Expand/Collapse to Show/Hide, the legacy behavior of the keyboard shortcuts should be preserved.

SUMO thread: https://support.mozilla.org/questions/1476220 

(In bug 1897411, there is discussion of a shortcut to expand the sidebar, but not to close it, so this is not a duplicate request.)
Bug: [HiRes scroll] Tab-bar scrolling multiple tabs per click
Status: UNCONFIRMED
Priority: --
Created: 2024-11-27 23:14:14+00:00
Resolved: 2024-12-27 16:39:10+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

set toolkit.tabbox.switchByScrolling, use a high-resolution scroll wheel mouse on wayland. Logitech MX master series are one of the few mice with this feature


Actual results:

each click of the mouse wheel scrolls 3 tabs instead of 1. By scrolling less than a full detent, you can select specific tabs. Basically, the gain is incorrect.


Expected results:

scroll to the next/previous tab
Bug: Custom titlebar doesn't properly update on fullscreen windows when leaving fullscreen.
Status: NEW
Priority: --
Created: 2024-11-27 23:27:52+00:00
Resolved: 2025-01-16 02:30:06+00:00

As noted by Ray in https://phabricator.services.mozilla.com/D229765:

> given two windows A and B:
> With the titlebar on: if you enter fullscreen in B, turn off the titlebar in A, and exit fullscreen in B, B will still have its titlebar. ❌
> With the titlebar off: if you enter fullscreen in B, turn on the titlebar in A, and exit fullscreen in B, B will now have its titlebar. ✔
> With the titlebar off: if you enter fullscreen in B, turn on the titlebar in A, turn off the titlebar in A, and exit fullscreen in B, B will now have a titlebar. ❌

This is because on fullscreen windows the customtitlebar attribute gets removed every time it changes, and doesn't get updated when leaving fullscreen (both things changed by bug 1499706).
Bug: Add ability to move toolbar buttons into vertical tabs sidebar
Status: NEW
Priority: P3
Created: 2024-11-28 04:49:15+00:00
Resolved: 2024-12-13 15:25:10+00:00

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

I enabled vertical tabs (on the right, with the collapsed sidebar, not the large sidebar). I right-clicked the top and clicked 'customise toolbar'. I could drag the downloads button out of the top toolbar, but there was no place on the right to drop the downloads button in the sidebar. I tried dragging it to the side anyway.


Actual results:

There was no place on the side to put the button, and when I dropped it where there should be a space, it went to the list of buttons in the middle of the customise screen


Expected results:

There should have been the vertical tabs toolbar on the side, and I should have been able to put the downloads button there.
Bug: SVG shortcut favicon on new tab page is cropped on the top and bottom
Status: NEW
Priority: P3
Created: 2024-11-28 09:27:35+00:00
Resolved: 2025-01-24 14:49:57+00:00

STR:
1. Pin https://www.cbsnews.com to the new tab page shortcuts.

Expected:
CBS icon is fully visible with a circular outer perimeter.

Actual:
CBS icon has a flat top and bottom indicating it is being cropped.

Occurs at all zoom levels. The image was previously PNG but recently changed to SVG. 

Also occurs on `about:firefoxview` but requires zooming to notice and mostly affects the bottom edge.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=47b1ae23989b8389b90ec9fed715d9eae6455ad7&tochange=ec6364b47f312809587d58ec8fe38e02d7f78976

Regressed by Bug 1494016.
Bug: Blank tab name if Firefox is restarted when tabs are loading
Status: NEW
Priority: P3
Created: 2024-11-28 10:06:34+00:00
Resolved: 2025-02-24 16:51:03+00:00

**Found in**
* 135.0a1 (2024-11-27)

**Affected versions**
* 135.0a1 (2024-11-27)
* 134.0b2
* 133.0
* 128.5.0esr


**Tested platforms**
* Affected platforms:  Windows 10x64, macOS 12, Ubuntu 24
* Unaffected platforms: none


**Steps to reproduce**
1. Open the bug 1913100 in a new tab.
2. Open the browser console.
3. Click on the bug 1913100 link using the middle click multiple times.
4. Quickly select the console and restart Firefox.
5. Observe tab names.


****Expected result****
* For the tabs that are not loaded a `New tab` name is displayed  (this happens on Good builds)

**Actual result**
* Blank tabs names are displayed.



**Regression range**
* pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=d65395a2bd805a5e66ffe91ef622c195c7a652bb&tochange=e38643d52e3dd6e9144212d92be4a5d1e9e41fd5 
* unfortunately I don't know which one is the regressor from the above list and mozregression cannot bisect further due to builds being too old

**Additional notes**
* Attached a screen recording.
Bug: Data URI XSS triggers via Homepage and new windows settings
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2024-11-28 12:34:37+00:00
Resolved: 2024-11-30 00:25:41+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

Summary:
Firefox browser accepts data URI xss payload to be saved in homepage custom URLs options and triggers it whenever browser is opened.

Component: Firefox Browser Version 133

Steps:
1. Go into settings > Home.
2. Edit options "Homepage and new windows" and select "Custom URLs" options.
3. Now put XSS Data URI payload in that and save.
4. Now whenever you close and open the browser, data URI xss gets triggered.

Impact:
If attacker saves such custom URLs in public or any victim system browser, it will get triggered everytime victim tried to open it.


Actual results:

Actual Results:
1) Firefox browser allowed to save data URI XSS payload to be saved in custom URLs.
2) Every time browser is opened, browser triggers that Data URI xss.


Expected results:

Expected Results:
1) Firefox security should not allow Data URI to be saved under custom URLs, there must be filter to only put https or http URLs.
2) Also if someone puts Data URI in homepage custom URLs, Browser must check the setting and see if off domain data URI is not executed.
Bug: Der eingebundene LiveChat funktioniert nicht
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2024-11-28 13:11:05+00:00
Resolved: 2024-12-31 07:03:58+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Steps to reproduce:

Der eingebundene LiveChat von Userlike funktioniert nicht  wie gewünscht auf unserer Shopseite. Was können wir tun? Eingebunden ist es über java script.
Aufgrund des Proxy und virtual Machine. 


Actual results:

Nichts. es öffnet sich kein Chatfenster zum starten der Kommunikation.


Expected results:

das Chatfenster öffnet sich und man kann eine Kommunikation starten
Bug: empty group doesn't removed from closedGroups when closed tabs restored one at a time
Status: RESOLVED
Priority: P2
Resolution: FIXED
Created: 2024-11-28 13:13:01+00:00
Resolved: 2025-01-16 15:01:28+00:00

Bug 1927774 add the ability to restore tabs form closed tab group.

After restoring all tabs from a deleted group `SessionStrore` does not remove the group from winData.closedGroups

The result of this 'ghost' group is that any attempt to reopen other closed tabs when there are other closed groups fails with this error

```shell
Uncaught NS_ERROR_ILLEGAL_VALUE: Invalid index: not in the closed tabs
    ssi_undoCloseTab resource:///modules/sessionstore/SessionStore.sys.mjs:4079
    ss_undoCloseTab resource:///modules/sessionstore/SessionStore.sys.mjs:449
    undoCloseTab chrome://browser/content/browser.js:6042
    oncommand chrome://browser/content/browser.xhtml:1
2 SessionStore.sys.mjs:4079
```
Steps to reproduce:

- open few tabs
- create group
- delete the group
- go to `History > Recently Closed Tabs` and restore each tab from that group.
- create another group and delete it.

Result:
- any call to `undoCloseTab()` will fail with the above error