1904149 - Smooth scrolling turns off for no reason

Status: UNCONFIRMED

(Core :: Panning and Zooming, defect, P3)

Description

[Łukasz]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:127.0) Gecko/20100101 Firefox/127.0

Steps to reproduce:

I'm using Firefox with general.smoothScroll enabled and:

general.smoothScroll.mouseWheel.durationMaxMS	120	
general.smoothScroll.mouseWheel.durationMinMS	120	
mousewheel.min_line_scroll_amount	39	
mousewheel.system_scroll_override.vertical.factor	100	
general.smoothScroll.currentVelocityWeighting	0	
general.smoothScroll.durationToIntervalRatio	50	
general.smoothScroll.lines.durationMaxMS	50	
general.smoothScroll.lines.durationMinMS	50	
general.smoothScroll.other.durationMaxMS	50	
general.smoothScroll.other.durationMinMS	50	
general.smoothScroll.pages.durationMaxMS	50	
general.smoothScroll.pages.durationMinMS	50	
general.smoothScroll.pixels.durationMaxMS	50	
general.smoothScroll.pixels.durationMinMS	50	
general.smoothScroll.scrollbars.durationMaxMS	50	
general.smoothScroll.scrollbars.durationMinMS	50

Actual results:

At random times when using Firefox, scrolling stops being smooth.
The general.smoothScroll option is still enabled, but scrolling is no longer smooth.
Gdy wyłączę i włączę Firefox, to scrollowanie znów jest płynne.

I have no idea why this is happening, I can't recreate it. This has happened many times before.
This always happened when I had my extensions enabled, and I can't test it without extensions because it happens spontaneously and I need my extensions on a daily basis.

Expected results:

Scrolling doesn't stop being smooth for no reason.

Comment 1

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

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

Comment 2

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

The severity field is not set for this bug.
:botond, could you have a look please?

For more information, please visit BugBot documentation.

Comment 3

[Alex Jakobi [:ajakobi]]

Hi, thank you for your report. Could you please try for a while with default values to the settings you have posted and let us know if the problem keeps occurring?

Comment 4

[Łukasz]

Alex Jakobi Hard topic. This doesn't happen every day, just from time to time.
And I don't want to have a different scrolling speed set every day, because it's inconvenient for me. And I would have to test for many days, with no guarantee of observing anything. :|(In reply to Alex Jakobi [:ajakobi] from comment #3)

Hi, thank you for your report. Could you please try for a while with default values to the settings you have posted and let us know if the problem keeps occurring?

Hard topic. This doesn't happen every day, but every now and then. I would have to set the default scrolling speed and use it for many days with no guarantee that I would notice anything. And a different scrolling speed is not comfortable for me. :|

Comment 5

[Alex Jakobi [:ajakobi]]

Would it be acceptable for you to reset the following settings to their defaults?

general.smoothScroll.currentVelocityWeighting	0	
general.smoothScroll.durationToIntervalRatio	50

These are the most interesting ones from our current understanding.

Comment 6

[Dan Robertson (:dlrobertson)]

Do you happen to have a reduced motion OS level setting on? E.g. gtk-enable-animations

Comment 7

[Łukasz]

(In reply to Alex Jakobi [:ajakobi] from comment #5)

Would it be acceptable for you to reset the following settings to their defaults?

general.smoothScroll.currentVelocityWeighting	0	
general.smoothScroll.durationToIntervalRatio	50

These are the most interesting ones from our current understanding.

Ok, I've restored these values ​​to their defaults, as you wanted.
It works just as well, so maybe these settings weren't necessary for me.

Now all you have to do is wait, and if it never happens again, it means that the problem no longer exists... or the problem exists, but in those settings. :D

(In reply to Dan Robertson (:dlrobertson) from comment #6)

Do you happen to have a reduced motion OS level setting on? E.g. gtk-enable-animations

No I do not have. I have animations turned on.

Comment 8

[Łukasz]

It just happened again. Smooth scrolling disabled itself.
What should I do?

I visited messenger.com, wykop.pl, discord.com, x.com.

My extensions are enabled because I use them.

Comment 9

[Łukasz]

Attachment: scroll-bug.mp4

Comment 10

[Łukasz]

It seems important: When I open a new Private Window now, smooth scrolling is also disabled in it. And in the Private Window, no extensions are enabled; I haven't granted permission for any extension to work in the private window.

Comment 11

[Botond Ballo [:botond]]

Maybe the modified preferences are a red herring, and the issue is actually related to bug 1851024.

Do you have Firefox Sync enabled? If so, this could be bug 1851024 (which was just recently fixed in Firefox 131).

Comment 12

[Łukasz]

Botond Ballo [:botond] Yes, I have Firefox Sync turned on.

Comment 13

[Łukasz]

For me, the smooth scrolling option is checked in the Firefox settings (as seen in the attached MP4), even when the scrolling is no longer smooth.

Comment 14

[Łukasz]

I discovered when smooth scrolling gets disabled—when I drag an image from Nautilus to Firefox.

I'm on Arch Linux with Cinnamon, and I'm using GNOME applications.

It's possible that dragging other files or doing so from a different program might cause something similar, but this is my initial finding. I'll probably test other environments as well.

---

(In reply to Alex Jakobi [:ajakobi] from comment #5)

(In reply to Botond Ballo [:botond] from comment #11)

(In reply to Dan Robertson (:dlrobertson) from comment #6)

Comment 15

[Łukasz]

Ah, I'm on X, not on Wayland.

Comment 16

[Botond Ballo [:botond]]

(In reply to Łukasz from comment #14)

I discovered when smooth scrolling gets disabled—when I drag an image from Nautilus to Firefox.

Thanks for the update. A few follow-up questions:

1. Can you trigger the bug reliably by dragging an image from Nautilus to Firefox, i.e. does it happen every time you do that?
2. Are you dragging the image to Firefox to open the image in a new Firefox tab (this is what I observe happening when I drop an image onto a tab with a random website open, which does not itself handle the drag-and-drop)? Or are you dragging it to a specific website which handles drag-and-drop (e.g. to upload the image somewhere)? In the latter case, could you give an example website/URL?

Comment 17

[Łukasz]

(In reply to Botond Ballo [:botond] from comment #16)

(In reply to Łukasz from comment #14)

I discovered when smooth scrolling gets disabled—when I drag an image from Nautilus to Firefox.

Thanks for the update. A few follow-up questions:

1. Can you trigger the bug reliably by dragging an image from Nautilus to Firefox, i.e. does it happen every time you do that?
2. Are you dragging the image to Firefox to open the image in a new Firefox tab (this is what I observe happening when I drop an image onto a tab with a random website open, which does not itself handle the drag-and-drop)? Or are you dragging it to a specific website which handles drag-and-drop (e.g. to upload the image somewhere)? In the latter case, could you give an example website/URL?

1. Yes, every time.
2. Yes, it works that way for a new tab as well. It also works for any current tab; it doesn’t need to be any specific site or a site with drag-and-drop support.

Comment 18

[Botond Ballo [:botond]]

Thanks. Unfortunately, I cannot reproduce the issue. However, we did have a recent report of an issue that has some similarity to this one (something related to scrolling goes wrong after a drag-and-drop): bug 1926830, and I'm expecting to get some more diagnostic information about that one soon. Let's see if perhaps it's the same underlying issue.

Comment 19

[Botond Ballo [:botond]]

(Also increasing the severity/priority here as based on the more recent developments, the issue is not likely to be related to customized preferences.)

Comment 20

[Łukasz]

This bug disappeared in 134.0b10 (64 bit).

Comment 21

[Łukasz]

Sorry, the error is back. I don't know why it disappeared, and I don't know why it came back.
But it's here again. :|