1985516 - Duplicate Taskbar Tab can be created if a tab is added to taskbar and removed from taskbar repeatedly

Status: NEW

(Firefox :: Web Apps, defect, P3)

Description

[Alex Cornestean]

Affected versions:

• Nightly (144.0a1/20250826095322)
• Beta (143.0b4/20250825091315)

Description:
A.
Repeatedly adding and removing a tab (4 actions in total) to/from taskbar, ending with the removal of the tab so it ends back in the main browser instance will prompt the user to pin the Taskbar Tab. Selecting to pin the Taskbar Tab to the taskbar will create a Taskbar Tab on the taskbar with the original tab still in the main browser instance.
Clicking the pinned Taskbar Tab will not open that item, but a duplicate Taskbar Tab item will be created and launched. The duplicate can be pinned as well, as a pinning notification is triggered for it. Returning the duplicate Taskbar Tab to the main browser instance via the pageAction will still keep the first Taskbar Tab on the taskbar which can only be removed via unpinning from the right click context menu.

B.
Repeatedly adding and removing a tab (9 actions in total) to/from taskbar, ending with the adding of the tab will trigger the notification multiple times. Selecting to pin the Taskbar Tab will also create a duplicate item on the taskbar keeping the same behavior as described above.

Steps to reproduce:

A.

1. Open https://www.wikipedia.org/ in a tab (make sure it’s not the only opened tab)
2. Click the pageAction to add the tab to taskbar
3. Once the Taskbar Tab window opens click the pageAction to remove it from taskbar
4. Repeat Steps 2 & 3 again so there are 4 actions of adding and removing a tab to/from taskbar and ending with the tab back in the main browser instance
5. A pinning notification will be displayed. Select to pin the Taskbar Tab to the taskbar
6. Notice a Taskbar Tab item appears on the taskbar
7. Click the Taskbar Tab item
8. Notice the original Taskbar Tab item does not launch, but instead a duplicate Taskbar Tab item is created which then launches
9. Notice that when the duplicate launches, a pinning notification is triggered for it as well
10. Return the duplicate Taskbar Tab back to the main browser instance via the pageAction
11. Click the original Taskbar Tab again and notice a duplicate is created and opened again

NOTE: This means that the original Taskbar Tab can be removed from the taskbar only by unpinning it via the right click context menu

B.

1. Open https://www.wikipedia.org/ in a tab (make sure it’s not the only opened tab)
2. Click the pageAction to add the tab to taskbar
3. Once the Taskbar Tab window opens click the pageAction to remove it from taskbar
4. Repeat Steps 2 & 3 again so there are 9 actions of adding and removing a tab to/from taskbar and ending with a Taskbar Tab on the taskbar
5. A pinning notification will be displayed. Select to pin the Taskbar Tab to the taskbar
6. Notice a duplicate taskbar item is created (this time the duplicate appears after the original opened Taskbar Tab and it behaves as the original tab from scenario A.)
7. Notice a second pinning notification is triggered
8. Click the duplicate taskbar item
9. Notice the duplicate Taskbar Tab item does not launch, but instead a new window of the original Taskbar Tab item is opened

NOTE: The original Taskbar Tab can be returned to the main browser instance, but the duplicate can only be removed from the taskbar by unpinning it via the right click context menu

NOTE for B: After performing Step 4, wait and do not select anything on the notification. Another notification will appear shortly, on top of the first one. Wait 10 seconds and then select Yes on the first notification and Yes on the second notification a few seconds later. As a result the issue with Scenario B will no longer occur.

Expected results:
Only one Taskbar Tab item should be created for one tab, regardless of the user adding/removing that tab to/from the taskbar.

Actual results:
Duplicate Taskbar Tabs can be created if a tab is added to taskbar and removed from taskbar repeatedly

Comment 1

[Alex Cornestean]

Attachment: A..mp4

Comment 2

[Alex Cornestean]

Attachment: B..mp4

Comment 3

[Alex Cornestean]

Attachment: B, but waiting a bit before pinning.mp4

Comment 4

[Nick Rishel [:nrishel]]

This is a combination of interactions between Bug 1975791 and Bug 1985658.