1928570 - Smooth scrolling option is broken on 132.0 for existing profiles

Status: UNCONFIRMED

(Core :: Panning and Zooming, defect)

Description

[hackerpcs]

Steps to reproduce:

Firefox automatically updated to v132.0. To work around the issue, I had to downgrade to 131.0.3, disable updates via group policy (HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox\\DisableAppUpdate=1) and launch Firefox 131.0.3 with "--allow-downgrade" to use my old profile and then on 131.0.3 it works as it should turning it on/off.

This was reported by another user too
https://forums.mozillazine.org/viewtopic.php?t=3126194

It does NOT happen on a clean profile ("%AppData%/Mozilla" folder renamed/moved), only on existing profiles

Actual results:

I noticed that smooth scrolling is on even though it's off in settings

Expected results:

Smooth scrolling should be turned off when the option is off.

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

[Hiroyuki Ikezoe (:hiro)]

Given that we've already cut off the relationship between Firefox Sync and the smooth scroll pref since Firefox 131 (bug 1851024), so Sync is unrelated I think.

Given that the issue happens on upgrading Firefox, there still remains an issue regressed by bug 1830103? Though I have no idea why it appeared on Firefox 132 upgrade. CCing Dan.

Or maybe Windows 11 24H2 update somehow changed the prefers-reduced-motion setting?

Comment 3

[hackerpcs]

It happened on a second different PC, both on Windows 10 22h2 (non-LTSC, general release) and I've never used Sync on both

Comment 4

[hackerpcs]

As user De52A found out, the problematic setting is "general.smoothScroll.mouseWheel"
https://forums.mozillazine.org/viewtopic.php?p=14987105#p14987105
if set to false, on v132.0 smooth scrolling is disabled (what I want and a workaround for me to use v132.0), what seems to be the problem is that "general.smoothScroll" ("Use smooth scrolling" on Settings UI) is ineffective, if set to false it doesn't disable smooth scrolling in general like it should and does in 131.0.3, it doesn't do anything.

All other general.smoothScroll.* for me are default and user.js removed or present doesn't fix the problem

Comment 5

[jg30]

Hey all, I'm De52A from MozillaZine, I just discovered another preference affected, it's general.smoothScroll.pages if set to false disables smoothscorlling in page up, page down, home and end buttons. On a non buggy profile disabling smooth scrolling disables it entirely, on a buggy profile individual preferences in about:config has to be modified in order to disable it.

Please, if you're able to test this, disable smooth scrolling in preferences (or general.smoothScroll in about:config), if the profile's buggy, it won't be disabled, if it's not buggy. it will be disabled properly.

Somebody else pointed out that https://bugzilla.mozilla.org/show_bug.cgi?id=1927094 might be related to this but I'm not entirely sure.

Comment 6

[Samuel Kalbfleisch]

I'm affected by this on Ubuntu 20.04 (Firefox package from the Ubuntu repo), so this doesn't appear Windows-related. After the upgrade to firefox-132.0+build1-0ubuntu0.20.04.1, mouse wheel smooth scroll appeared again despite being disabled in settings, and toggling the setting does not have any effect.
I can confirm that setting general.smoothScroll.mouseWheel to false disables smooth scrolling for me.
In case it's relevant, I launch Firefox using env -uGDK_CORE_DEVICE_EVENTS MOZ_USE_XINPUT2=1 firefox and am on XFCE.

Comment 7

[jg30]

I forgot to add modifying general.smoothScroll.other to false disabled it in home and end buttons too. Also, thank you Samuel, finally we're not alone! :D

Comment 8

[Botond Ballo [:botond]]

I did a quick check of this on Linux:

• downloaded Firefox 131 from https://archive.mozilla.org/pub/firefox/releases/131.0.3/linux-x86_64/en-US/
• unchecked "Use smooth scrolling in preferences"
• verified that scrolling is now instant (not smooth)
• upgraded to Firefox 132 (in Help --> About Firefox)
• checked whether scrolling is still instant

For me, scrolling was still instant (i.e. smooth scrolling is disabled) after the upgrade. So there's something more to it needed to trigger the issue that we need to figure out to reproduce.

Comment 9

[Botond Ballo [:botond]]

See also bug 1912246 for a similar report in an earlier version.