1419649 - When I close one of several tabs, after the tab closes, the wrong existing tab is opened as the current tab

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, enhancement, P3)

Description

[publicly.visible]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171112125346

Steps to reproduce:

If I have several tabs open, and I close one of them, I expect the tab that I'd been viewing just prior to the closed tab (the most recently viewed tab) to reopen.

Hopefully this example will make it clearer:

1. open a new Firefox window
2. go to 'www.bbc.co.uk'
3. at the top of the page is a menu, ctrl+click on 'News'.  This opens 'www.bbc.co.uk/news' in a new tab
4. ctrl+tab to go back to 'www.bbc.co.uk'
5. ctrl+click on 'Sport'.  This opens 'www.bbc.co.uk/sport' in a new tab

Now have 3 tabs open, in order of most recently viewed to oldest viewed, they are:
  www.bbc.co.uk/sport
  www.bbc.co.uk
  www.bbc.co.uk/news

6. ctrl+W to close 'www.bbc.co.uk/sport'

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Environment
-----------

Windows 7 Home Premium SP 1

Firefox 57.0 (64-bit)
No Add-ons or Extensions
3 Plugins: OpenH264 Video Codec, Widevine Content Decryption Module, Shockwave Flash
4 Legacy Extensions, all deactivated

'Tabs' options:
  yes  Ctrl+Tab cycles through tabs in recently used order
  yes  Open new windows in a new tab instead
  yes  When you open a link in a new tab, switch to it immediately
  no   Show tab previews in the Windows taskbar



Actual results:

The 'www.bbc.co.uk/news' tab opens (the oldest viewed tab)



Expected results:

The 'www.bbc.co.uk' tab should open as it is now the most recently viewed tab.

Comment 1

[publicly.visible]

This might be a better summary:
ctrl+W (after closing the current tab) does not switch to the most recently used tab.

FYI I get the expected behaviour by following the ctrl+W with ctrl+tab

Comment 2

[100の人]

This was not a problem until Firefox 118, but now this problem occurs in Firefox 119.0.

The replacement of gBrowser.selectedTab was done in the capturing phase of the select event fired when a tab is selected in Firefox 118, but in Firefox 119.0 it was done in the bubbling phase, so there may be a connection.

Comment 3

[100の人]

Attachment: The video recorded by reproducing the problem

I attach the video recorded by reproducing the problem.

Steps to reproduce

1. Open a new tab on the far right and open https://a.test/.
2. Open a new tab on the far right and open https://b.test/.
3. Open a new tab on the far right and open https://c.test/.
4. Select the tab https://a.test/, the first tab from the left.
5. Select the tab https://c.test/, the third tab from the left.
6. Close the current tab https://c.test/, the third tab from the left.

Expected result

The tab https://a.test/, first tab from the left, becomes the current tab.

Actual result

The tab https://c.test/, second tab from the left, becomes the current tab.

Comment 4

[100の人]

(In reply to 100の人 from comment #3)

Actual result

The tab https://c.test/, second tab from the left, becomes the current tab.

Typo. The correct is below.

Actual result

The tab https://b.test/, second tab from the left, becomes the current tab.

Comment 5

[Renato Spencer]

Hi Triage Owner [:niklas] and all,

I am triaging this UNCONFIRMED enhancement (1419649) to check its status in the latest Firefox Beta build. The bug relates to tab selection order upon closing the current tab.

TEST ENVIRONMENT:

• OS: Windows 10 (22H2)
• Firefox Version: 146.0b5 (64-bit)
• Configuration: Clean Profile (Default Settings)

ANALYSIS AND REPRODUCTION ATTEMPT (Testing MRU vs. Neighbor Tab Logic):

• STEPS TO REPRODUCE (MRU Test):

  1. Open four tabs: [Tab A | Tab B | Tab C | Tab D].
  2. Set MRU: Activate Tab A (MRU = A).
  3. Activate Tab D (D is current).
  4. Close Tab D (Ctrl+W).

• ACTUAL RESULTS: The active tab is Tab C (the immediate neighbor of the closed tab D).

• EXPECTED RESULTS (Based on reporter's request): The active tab should have been Tab A (the MRU tab).

Scenario Conclusion:
The current behavior of Firefox 146.0b5 is consistent across tests: upon closing the active tab, focus shifts to the immediate neighboring tab (following tab index) rather than the Most Recently Used (MRU) tab.

CONCLUSION AND RECOMMENDATION:

The issue is NOT reproducible as a defect/regression in the latest Beta build. The observed behavior appears to follow a different design logic (Neighbor Tab) than the reporter expected (MRU Tab).

Therefore, I recommend marking this UNCONFIRMED issue as RESOLVED/WORKSFORME, unless there is documentation confirming that the MRU logic is the intended default behavior for the latest Firefox builds.

Thank you.