1655950 - Firefox scrolls down when clicking to play a video on old Facebook

Status: RESOLVED DUPLICATE of bug 1655398

(Core :: DOM: CSS Object Model, defect)

Description

[Alexandru Trif, Desktop QA [:atrif]]

Attachment: fb_video_issue.gif

Affected versions

• 80.0b1 (20200728204253)

Affected platforms

• Windows 10x64
• macOs 10.12
• Ubuntu 18.04

Steps to reproduce

1. Open Firefox and go to https://www.facebook.com/ and scroll down (old Facebook).
2. Click Play on a random video.

Expected result

• Video plays as expected.

Actual result

• Firefox scrolls down.

Regression range

• I will search for one ASAP.

Notes

• Attached a screen recording.
• I cannot reproduce the issue using the latest Firefox Nightly 81.0a1 (20200728213249) or Firefox 79.0 (20200720193547).
• On the unaffected version, the video starts with autoplay but on the affected version they don’t start automatically.
• Also the scroll bar sometimes jumps by itself when moving the mouse.

Suggested Severity: S3

Comment 1

[Darkspirit]

https://hg.mozilla.org/integration/autoland/shortlog/1fa3c63f82d2
Last bad: mozregression --repo autoland --launch 51da3f1e63df8830d3d1149b9ded1159b53aef3e --pref gfx.webrender.all:true -a https://www.facebook.com/pg/failarmy/posts/
First good: mozregression --repo autoland --launch 1fa3c63f82d2 --pref gfx.webrender.all:true -a https://www.facebook.com/pg/failarmy/posts/