1617222 - [Fission] Full screen video on YouTube doesn't work

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Andrew McCreight [:mccr8]]

Steps to reproduce:

1. Have Fission enabled.
2. Open a new tab, paste https://www.youtube.com/watch?v=V9E43cCJHWU into the URL bar, hit enter to load the page.
3. Start the video playing, if it isn't already.
4. Hover the mouse over the video, so the video controls appear, and click on rightmost thing to go into full screen mode. Alternatively, just hit 'f'.

Expected behavior: The video should go into full screen mode.

Actual behavior: Nothing happens.

I used mozregression, and it says bug 1556627 is the cause of the regression.

Comment 1

[Andrew McCreight [:mccr8]]

I thought I originally was seeing the same issue (full screen mode not working) on Twitch, but in a Twitch tab I opened this morning it is working so I don't know.

It works just fine in a non-Fission window.

Comment 2

[Nika Layzell [:nika] (ni? for response)]

Marking as blocking M5 (fission dogfooding).

Henri, this appears to be regressed by your changes. Can you look into it?

Comment 3

[Chris Peterson [:cpeterson]]

YouTube's full screen button or pressing 'f' works for me in 75 Nightly (2020-02-21) on Windows 10.

Comment 4

[Andrew McCreight [:mccr8]]

It works for me if I shift-click the link in comment 0, but not if I copy and paste the link into a new tab and hit enter.

Comment 5

[Andrew McCreight [:mccr8]]

I updated the STR in comment 0.

Comment 6

[Danny Colin [:sdk]]

I can reproduce this bug on other websites/video players in 75.0a1 (2020-02-21) on Linux. This include the builtin player.

Comment 7

[Henri Sivonen (:hsivonen)]

This bug may or may not actually depend on bug 1614297 or bug 1615548, but those are the ones that have the most direct repro mechanics, so it doesn't make sense to pursue this one before those are fixed.

Comment 8

[Chris Peterson [:cpeterson]]

Andrew and Danny, can you share your about:support and any non-default pref values you're using?

Nika wonders if this bug is related to window focus problems.

Tracking for Fission Nightly (M6) because full screen YouTube works for some people.

Comment 9

[Andrew McCreight [:mccr8]]

I was able to reproduce it in a clean profile created by mozregression. Note that I had to paste the YouTube URL for full screen to not work. When I followed the link in comment 0, full screen worked.

Comment 10

[Andrew McCreight [:mccr8]]

I also reproduced the issue just now by creating a new profile, starting Firefox with the profile, setting the Fission pref to true, restarting, then following the steps in comment 0.

Comment 11

[Andrew McCreight [:mccr8]]

Chris, did you try my updated STR in comment 0 where the URL is copy and pasted?

Comment 12

[Andrew McCreight [:mccr8]]

I enabled WebRender via a pref, and I still can't enter full screen mode.

Comment 13

[Chris Peterson [:cpeterson]]

(In reply to Andrew McCreight [:mccr8] from comment #11)

Chris, did you try my updated STR in comment 0 where the URL is copy and pasted?

I did. Full screen still works for me (clicking the button or pressing the 'f' keyboard shortcut) if I copy/paste the YouTube URL.

Comment 14

[Chris Peterson [:cpeterson]]

Actually, I can reproduce the full screen problem now on both YouTube and Netflix. In a non-Fission window, full screen works for YouTube and Netflix.

Comment 15

[Danny Colin [:sdk]]

Attachment: ff-about-support.txt

(In reply to Chris Peterson [:cpeterson] from comment #8)

Danny, can you share your about:support and any non-default pref values you're using?

I tested in a fresh profile and I still has the issue (see attached file for about:support info).

Comment 16

[Andrew McCreight [:mccr8]]

(In reply to Chris Peterson [:cpeterson] from comment #14)

Actually, I can reproduce the full screen problem now on both YouTube and Netflix. In a non-Fission window, full screen works for YouTube and Netflix.

Thanks for checking again!

Full screen on the video player for the MoCo internal call also doesn't work. :)

Comment 17

[Henri Sivonen (:hsivonen)]

At the very least the "is this document is the active tab" check needs to be changed to work on BrowsingContext instead of DOM window.

Comment 18

[Henri Sivonen (:hsivonen)]

Bug 1618102 was enough to fix these steps to reproduce for me. Did it fix this for you? (I expect there still to be breakage around implicitly breaking out of the full-screen state.)

Comment 19

[Andrew McCreight [:mccr8]]

Yeah, it works for me now. Thanks.