1854118 - Upon restart, order of window-items in taskbar is not restored

Status: RESOLVED DUPLICATE of bug 1235231

(Core :: Widget: Win32, enhancement, P5)

Description

[Lucas Resch]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/117.0

Steps to reproduce:

I use three screens both at work and at home. On each of them I have a dedicated Firefox window open at all times. The first window is on my left screen, the second on my middle, and the third on my right screen. When I restart my computer the second and third window always switch their order. To fix this I need to close the one that is not in the correct order and restore it via History > Recently Closed Windows. I have to do this twice a day, once for each computer. One is using Windows 10 the other Windows 11.

Actual results:

Upon a restart of Firefox the order of Firefox windows changes.

Expected results:

No matter how I restart Firefox the order of its windows should stay the same.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Win32' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Ray Kraesig [:rkraesig]]

This may end up being a Firefox :: Session Restore bug instead... but if closing and reopening the windows puts them where they should be, rather than where they just were, it probably is a Widget bug.

• Does this only happen when restarting the computer, or does just exiting (Ctrl+Shift+Q) and reopening Firefox also reproduce the issue?
• If you create a new profile, start Firefox within it, and set up some windows accordingly, can you reproduce the bug in that new profile?
• What are the resolutions of your monitors?
• If you change which monitor is considered the "primary" monitor by Windows itself (which doesn't need to involve changing their relative effective positions), does this affect which Firefox windows get swapped?
• If you manually swap the windows by dragging them to their desired positions, rather than by closing and reopening them, does this change anything on subsequent Firefox startups?

Comment 3

[Lucas Resch]

(In reply to Ray Kraesig [:rkraesig] from comment #2)

This may end up being a Firefox :: Session Restore bug instead... but if closing and reopening the windows puts them where they should be, rather than where they just were, it probably is a Widget bug.

1. Does this only happen when restarting the computer, or does just exiting (Ctrl+Shift+Q) and reopening Firefox also reproduce the issue?
2. If you create a new profile, start Firefox within it, and set up some windows accordingly, can you reproduce the bug in that new profile?
3. What are the resolutions of your monitors?
4. If you change which monitor is considered the "primary" monitor by Windows itself (which doesn't need to involve changing their relative effective positions), does this affect which Firefox windows get swapped?
5. If you manually swap the windows by dragging them to their desired positions, rather than by closing and reopening them, does this change anything on subsequent Firefox startups?

Hi, I'm currently travelling and unable to try out additional things to reproduce the issue. But I can answer some of your questions.

1. Sadly unable to reproduce until I get back home in about two weeks
2. Same as 1.
3. 1920x1080 on all three
4. Same as 1.
5. Same as 1, though I don't expect that to change anything about their order in the taskbar widget.

Maybe to clarify: The windows open on the correct screen but their order in the Windows taskbar widget is wrong.

Comment 4

[Ray Kraesig [:rkraesig]]

Maybe to clarify: The windows open on the correct screen but their order in the Windows taskbar widget is wrong.

Oh. Yes, that does clarify, thank you. That's not something we have much power over — Windows is ultimately free to reorder taskbar items however it pleases, and historically has. There isn't even a documented way to ask the taskbar what order it's showing the windows in, much less reorder them.

On the other hand, if you're consistently seeing the taskbar items appear in a particular order, there may be something we can do to at least make it more likely that windows are created in the same order between sessions. It can't be done perfectly without APIs that Microsoft doesn't provide, but we can probably do better than we are.

At any rate, you can disregard the other questions. I'll adjust this issue's title and metadata accordingly.