1473055 - Youtube scroll position is not correctly restored from a previous session

Status: RESOLVED WONTFIX

(Firefox :: Session Restore, defect)

Description

[Cristian Baica [:cbaica], Release Desktop QA]

Attachment: Youtube scroll position

[Affected versions]:
- Fx63.0a1
- Fx62.0b5
- Fx60.1.0ESR

[Affected platforms]:
- macOS 10.13
- Windows 10 x64
- ubuntu 16.04 LTS

[Steps to reproduce]:
1. Launch Firefox.
2. Open a new window and go to reddit.com and scroll down through the site.
3. Open another window and go to amazon.com and scroll down through the site.
4. Open another window and go to youtube.com and scroll down through the videos and video sections.
5. Open the Hamburger menu and close Firefox.
6. Re-launch firefox with the same profile.
7. Open the hamburger menu and click the 'Restore Previous Session' option.

[Expected result]:
- All windows should be restored and scrolled to the position before Firefox was closed.

[Actual result]:
- The window containing the youtube page does not have the scroll progression correctly restored.

[Regression range]:
- I am gonna look into the regression range as soon as possible.

[Additional notes]:
- The reddit and amazon pages have the scroll progression correctly restored.
- This could be a website loading related issue? (the content the user scrolled to is not loaded with the restore session option?)

Comment 1

[Cristian Baica [:cbaica], Release Desktop QA]

This does not look like a recent regression since I could reproduce this issue with Fx 34.0a1.

This looks like a website issue. Firefox attempts to restore the scroll progression, but reaches the bottom of the video list before the section that was previously viewed is loaded and remains stuck there. Is this fixable?

Comment 2

[Liz Henry (:lizzard Please n-i to RyanVM, jcristau, or pascal)]

Too late to fix in 61, we could still take a patch in 63 or possibly 62 early beta. 
This doesn't sound like a major issue, so I'll leave it for triage from the component owners.

Comment 3

[Mike de Boer [:mikedeboer]]

(In reply to Cristian Baica [:cbaica], Release Desktop QA from comment #1)
> This looks like a website issue. Firefox attempts to restore the scroll
> progression, but reaches the bottom of the video list before the section
> that was previously viewed is loaded and remains stuck there. Is this
> fixable?

This is indeed a dynamically loading list, which grows the page to a potentially infinite size. Since this relies heavily on many XHRs, dynamically inserting content, we can't reliably restore to this state.