1959751 - Unable to scroll through open windows of Firefox in Windows taskbar

Status: UNCONFIRMED

(Core :: Widget: Win32, defect)

Description

[s.knudsen]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0

Steps to reproduce:

I am no longer given the option of being able to scroll through my open instances of Firefox. Being that I have over 60 instances (Not Tabs) of Firefox open at a time there should be a little arrow at the bottom of them that helps me scroll down, and then one should appear up at the top if I want to scroll back up.

Actual results:

The scrolling arrow does not appear.

When using my primary smaller horizontal monitor, it only shows 28 open instances. When making my larger vertical monitor the primary monitor, I can see 62 open instances (Not Tabs). Either way, the little arrow no longer pops up under the open instances list allowing me to be able to scroll to what instance I want to view.

Expected results:

Arrow should appear for scrolling but no longer does. I am not sure if it happened after a Firefox or Windows upgrade. No new add-ons were added. No new software was added. Firefox is up to date. Restarting it, restarting Windows, emptying cache, and starting Firefox in troubleshooting mode, nothing helps.

Comment 1

[Francesco Lodolo [:flod]]

Being that I have over 60 instances (Not Tabs) of Firefox open at a time there should be a little arrow at the bottom of them that helps me scroll down, and then one should appear up at the top if I want to scroll back up.

Can you clarify what an instance is? Do you mean a window?
Do you have a screenshot of the arrow you mention?

Comment 2

[s.knudsen]

Yes, when I say instances I am referring to a Window. I have 60+ Windows open, and god knows how many tabs.

There is no way of me taking a screenshot of something that is not showing up.

When I go to my taskbar and hover over the Firefox icon, all the open Windows of Firefox will pop up. If there is more than fits on the screen, a scrolling arrow on a horizontal bar should appear at the bottom of them.

Comment 3

[David Parks [:handyman]]

Thanks s.knudsen, there has been some work involving bugs with the taskbar recently and your problem sounds like one that may already be fixed. Can you download and try Firefox Nightly (at the bottom of the page)? That build of Firefox includes the latest fixes. If that works, just let us know here.

If that doesn't work then maybe you can help us isolate the cause by running mozregression. There is a short video at that link explaining what it is and how it works but the idea is very simple -- you start by choosing the most recent version of Firefox that you are convinced did not have the bug. Then, mozregression will download and run a series of builds where you run your bug reproducing steps and tell it whether the bug was present or not. When it's done, it will basically tell you which code introduced the bug, in the form of a "push log URL" that you would then paste into a comment here. That would help us to know where to focus. One major caveat: as you mention in comment 0, this could be due to a Firefox change or a Windows change. If Windows is the cause then mozregression won't help -- all Firefox builds would obviously reproduce the error. Of course, knowing this would also be a huge help.

Thanks again for the thorough bug report!

Comment 4

[s.knudsen]

Firefox shows open Windows by their name, stacked vertically from bottom to top of the screen.

Firefox Nightly shows open Windows by a small thumbnail image of the open WIndow and they are arranged horizontally across the screen.

Unless there is a way for me to change this in Firefox Nightly (which I can't figure out), this will not help me.

Comment 5

[David Parks [:handyman]]

(In reply to s.knudsen from comment #4)

Firefox shows open Windows by their name, stacked vertically from bottom to top of the screen.

Firefox Nightly shows open Windows by a small thumbnail image of the open WIndow and they are arranged horizontally across the screen.

Ah, I see this now. The confusion was because most users probably haven't seen it before. The issue is that, when you have a lot of Windows open (for me on this laptop I need at least 19 windows open) and you mouse over the icon for the application in the taskbar, instead of the usual thumbnail previews of the windows of the application, you will get a list of textboxes showing the window titles. I'd take a picture but Snipping Tool is currently not allowing delayed fullscreen images, so getting a picture of the mouseover isn't possible. But to reproduce, just hammer Ctrl+N until this happens.

I don't see any scrollbar, so I assume it is normally there and that is the bug. This is probably about WS_SYSMENU but that can be answered by mozregression.

Comment 6

[David Parks [:handyman]]

To be clear, I see the vertical list of window names in the latest Nightly when I have enough windows. I assume from comment 4 that the reporter doesn't see the vertical list in Nightly.