1512599 - [Youtube] Going back to an original video that was minimized (minivideo) will not display from top page

Status: RESOLVED WONTFIX

(Web Compatibility :: Site Reports, defect, P1)

Description

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

Attachment: Screencast showing the issue

[Affected versions]:
- RC 64.0-build3
- DevEdition 65.0b2-build1 
- Latest Nightly 65.0a1

[Affected platforms]:
- macOS 10.13
- Windows 7 32bit
- Ubuntu 18.04 64bit

[Steps to reproduce]:
1. Start Firefox
2. Open any youtube video
3. Scroll in the page so a part of the video is hidden
4. Click the minivideo button inside the video
5. Click the minivideo video so it will get maximized

[Expected result]:
- When maximized, user has the top of the page displayed.

[Actual result]:
- Portion of the top video is cut off, the page is maximized but scrolled.

[Regression range]:
- Not a regression since most certainly this is something from youtube side. (60 nightly was also affected).

[Additional notes]:
- Chrome does not have this issue, when maximizing page, it will be always displayed from the top.

Comment 1

[Mike Taylor [:miketaylr]]

Tom, can you take a look? Chrome does scroll the document so the video is displayed (though not entirely to the top?) while Firefox doesn't.

Comment 2

[Thomas Wisniewski [:twisniewski]]

It doesn't seem as though they bother to change the scroll position at all in Firefox. The video is just shifted back into place, but the scroll position is kept as-is (no matter how far down the page I scroll before clicking the mini-video).

Unfortunately, I can't tell what's causing the scrolling in Chrome. It doesn't seem to be setting Element.prototype.scrollTop or calling Element.scrollIntoView or window.scroll/scrollTo/scrollBy. It's also not using the new picture-in-picture APIs.

I think we might just have to contact Google to get more insight here.

Comment 3

[Mike Taylor [:miketaylr]]

Thanks Tom. I sent an email to our YT partner mailing list.

Comment 4

[Thomas Wisniewski [:twisniewski]]

According to YouTube's response, they actually want Firefox's behavior in this case; that is, to retain your scroll position, not jump to the top. They don't seem to feel they can make it work 100% reliably, though. Based on that we might as well close this as a WONTFIX, since it's intended (or at least expected) behavior.