Affected versions

• 83.0 (20201112153044)
• 84.0b4 (20201122152513)
• 85.0a1(20201123214551)

Affected platforms

• Windows 10x64
• macOS 10.15
• Ubuntu 18.0

Steps to reproduce

1. Open Firefox and https://bug1241394.bmoattachments.org/attachment.cgi?id=8710335.
2. Scroll using the mouse wheel.

Expected result

• The scroll on the page performs as expected.

Actual result

• Scrolling is not working or it’s working and stops after a few scrolls.

Regression range

• I will search for one ASAP.

Notes

• If the issue is not reproducible press up/ down arrow button from the keyboard or drag the scroll bar and then try to scroll.
• After using auto scrolling on the page the issue is not reproducible.

Suggested Severity: S3

It fails with webrender. Works without. With webrender forced on the behaviour changes several times, but this is one regression range

https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0d4e73bc2cd705d7a021c75a0e8aeb174ab4db59&tochange=317b91c1fbd51e48238d05bb3e90663245e751f3

thinking it could be

https://hg.mozilla.org/mozilla-central/rev/5fc179e245d51289f1f7bcaba0c29189d3336fbf

(In reply to Timothy Nikkel (:tnikkel) from comment #1)

It fails with webrender. Works without. With webrender forced on the behaviour changes several times, but this is one regression range

https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0d4e73bc2cd705d7a021c75a0e8aeb174ab4db59&tochange=317b91c1fbd51e48238d05bb3e90663245e751f3

thinking it could be

https://hg.mozilla.org/mozilla-central/rev/5fc179e245d51289f1f7bcaba0c29189d3336fbf

Thank you! Changing the flags based on the above.

Filling in bug 1421380 as the suspected regressor. Also updating severity to S3 as suggested in comment 0, and since we've been shipping this regression for 20+ releases with no user reports that I'm aware of.

Scroll doesn't work on Jetlag page on 87.0b4 under Ubuntu 20.04 as well.

(In reply to Catalin Sasca, QA [:csasca] from comment #4)

Scroll doesn't work on Jetlag page on 87.0b4 under Ubuntu 20.04 as well.

Is it the same issue as this bug though?

(In reply to Timothy Nikkel (:tnikkel) from comment #5)

(In reply to Catalin Sasca, QA [:csasca] from comment #4)

Scroll doesn't work on Jetlag page on 87.0b4 under Ubuntu 20.04 as well.

Is it the same issue as this bug though?

In case of jetlag.photos, dom.event.wheel-deltaMode-lines.always-disabled = true(default in Nightly) fixes.
So, I think it is a different bug.

So then should I file a new bug for jetlag?

Yes please.

Filled Bug 1696106 for the Jetlag page scrolling issue.

This does appear to be fixed by the patches in bug 1765204.

I am also unable to reproduce the issue with the fixes for bug 1765204

Thanks for checking, let's close this as a duplicate.