1344342 - Regression Scrolling is not smooth when I click on scrollbar to scroll the page sometimes

Status: RESOLVED DUPLICATE of bug 1326686

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

Description

[684sigma]

I have a problem with Firefox Beta 52. I don't remember it on older versions like Firefox Release 45.
Sometimes scrolling is not smooth when I click on scrollbar to scroll the page sometimes.
It happens unpredictably, however, I noticed one specific scenario when it happens

1. Open https://bugzilla.mozilla.org/show_bug.cgi?id=1344309
2. Duplicate the tab
3. Switch to the new tab, click on the free space in scrollbar to scroll the page

Result: scrolling is not smooth
Expected: should be smooth

Comment 1

[Loic]

I can't replicate the issue, does it work better with a fresh profile?
https://support.mozilla.org/t5/Install-and-Update/Use-the-Profile-Manager-to-create-and-remove-Firefox-profiles/ta-p/2914

Comment 2

[684sigma]

(In reply to Loic from comment #1)
> I can't replicate the issue, does it work better with a fresh profile?
> https://support.mozilla.org/t5/Install-and-Update/Use-the-Profile-Manager-to-
> create-and-remove-Firefox-profiles/ta-p/2914

I used a new profile when reported the bug.

> I can't replicate the issue

It is unclear, what browser version did you test and how many times... I said that it happens sometimes, not always. About 7 of 10 times.
Try also a heavy/long page like https://en.wikipedia.org/wiki/Main_Page

Comment 3

[Loic]

As triager, I always test the current release (currently 51) and Nightly (currently 54).

Comment 4

[684sigma]

(In reply to Loic from comment #3)
> As triager, I always test the current release (currently 51) and Nightly
> (currently 54).

How many times? I said that it happens sometimes, not always. About 7 of 10 times.
Try also a heavy/long page like https://en.wikipedia.org/wiki/Main_Page
"Scrolling is not smooth" means that the page and scrollbar just teleport to new position, without animation.

Could you actually try it on reported version? Without that you can't distinguish 3 possibilities: (1) the bug was fixed, (2) you didn't do exactly what I reported, (3) the bug is specific to my machine.
By the way, if (3) is the case, then the bug is still valid, right? Then what do I do, report it again for somebody else to test it? Can you provide me with some logging to prove that it really happens?

Comment 5

[Justin [:JW_SoftvisionQA]]

I could not reproduce this issue, by going to https://en.wikipedia.org/wiki/Main_Page nor doing the steps in the description, on my machine  	Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0

1. Could you go to about:support and paste your User Agent?

2. Could you take a screencast of this happening?

Comment 6

[684sigma]

Attachment: bug 1344342 detailed, by reporter.webm

(In reply to Justin [:JW_SoftvisionQA] from comment #5)
> I could not reproduce this issue, by going to
> https://en.wikipedia.org/wiki/Main_Page nor doing the steps in the
> description, on my machine  	Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0)
> Gecko/20100101 Firefox/52.0
> 
> 1. Could you go to about:support and paste your User Agent?
> 
> 2. Could you take a screencast of this happening?

1. User Agent 	Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0
2. Attached video

If you did something differently than shown in the video, please tell me how I could improve description in the first comment. Pls notify me if there're any ways to log this or other reasonably short instructions that would speed up fixing this bug.

Comment 7

[Ryan Hunt [:rhunt]]

Bug 1326686 has a similar description but different steps to reproduce.

A possible fix for it was posted in that bug, would you be able to run a version with the fix and see if it solves your problem?

Use the installer here:
https://queue.taskcluster.net/v1/task/dN_3cefwTuSi3xqcATIazQ/runs/0/artifacts/public/build/install/sea/firefox-53.0a1.en-US.win32.installer.exe

Comment 8

[684sigma]

This bug doesn't happen in the "version with the fix" you provided.

Comment 9

[Kartikaya Gupta (email:[e-mail])]

Thanks. Let's mark this as a dependency for now. Once bug 1326686 lands we can dupe this over assuming it still fixes the problem.

Comment 10

[Botond Ballo [:botond] [away until Oct 19]]

684sigma, could you confirm that the issue is no longer present in the latest Nightly? Thanks!

Comment 11

[Kartikaya Gupta (email:[e-mail])]

Optimistically marking as a dupe since 684sigma hasn't responded. Leaving needinfo for now.

Comment 12

[Botond Ballo [:botond] [away until Oct 19]]

Clearing stale needinfo.