1654225 - [scroll-anchoring] Page is shaking while loading on CNN Travel

Status: NEW

(Core :: Layout: Scrolling and Overflow, enhancement, P3)

Description

[Alexandru Trif, QA [:atrif]]

Attachment: cnn_travel_shaking.gif

Affected versions

• 80.0a1 (20200720214226)
• 79.0 (20200720193547)
• 78.0.2 (20200708170202)

Affected platforms

• Windows 10x64
• macOs 10.12
• Ubuntu 18.04

Steps to reproduce

1. Open Firefox and access/reload a random CNN travel article (e.g: link)
2. Scroll down and wait for the page to load.

Expected result

• The page is correctly loaded.

Actual result

• Page is shaking after being loaded.

Regression range

• Reproducible with Firefox 74.0a1 (20200202214642). I will search for one ASAP.

Notes

• Attached a screen recording.
  Severity S3

Comment 1

[Alexandru Trif, QA [:atrif]]

Attaching regression range:
Last good revision: ed68c008e5d8db0940a1fbc31bfc24efccba6c26 (2019-01-10)
First bad revision: c1894cbb4e7150a3a4a16e5d0702e038e7bd466f (2019-01-11)
Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=ed68c008e5d8db0940a1fbc31bfc24efccba6c26&tochange=c1894cbb4e7150a3a4a16e5d0702e038e7bd466f

Note that on the good build the scroll is shifted up after loading like seen in the video: link.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

So, to be clear, it shakes a bit while it loads, right? But once loaded it stays stable doesn't it?

That regression range includes bug 1305957 which implemented scroll anchoring which is what causes the giggling, but it seems better than jumping back up.

Comment 3

[Alexandru Trif, QA [:atrif]]

(In reply to Emilio Cobos Álvarez (:emilio) from comment #2)

So, to be clear, it shakes a bit while it loads, right? But once loaded it stays stable doesn't it?

Yes, after the page is loaded the scroll is stable.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Thanks for checking!

I think this is mostly working as expected then. There are some issues (it shouldn't shake), but the behavior is better than our previous behavior.