Affected versions

• macOS 10.14
• Ubuntu 18.04 x64
  *Windows 10 x64

Affected platforms

• ESR 60.9
• Firefox 68.0.2
• Nightly 70.0a1

Steps to reproduce

1. Go to Hulu and login with a valid account.
2. Watch a video with subtitles.
3. Open the video in Fullscreen using the context menu.

Expected result

• The subtitles are displayed.

Actual result

• The subtitles are missing.

Regression range

• I will try to fin one as soon as possible, if there is one.

Additional notes

• If you enter fullscreen via the "Fullscreen" button this issue is not reproducing.

:drno, do you know who should look at this?

I don't think this is fixable unless we just remove the fullscreen menu.

Although I haven't really tried to reproduce (I don't have Hulu account), but my guess is that, the context menu is the browser context menu for the <video> element, and it would only fullscreen the <video> element. However, the subtitle is usually a separate element outside the <video>. If you ask browser to just fullscreen the <video> element, then any other element on the page would not be visible.

If you use the fullscreen button provide by the website, on the other hand, the website would ensure fullscreening an element which contains both the video and all its controls as well as the subtitles.

There is no way browser context menu can be aware of what element to fullscreen other than the video element.

So I would say this is either an INVALID, or it should be a bug of Toolkit :: Video/Audio Controls to remove such menu item (to avoid confusing user if we decide so).

I tried to find a regression for this issue but I didn't manage to reproduce it under Fx 69.0a1 (20190520) and 68.0 RC versions. Due to the fact that Hulu requests newer Fx versions to run the player I am unable to check if this is a regression or not.

We could disable a bunch of options from the context menu when built-in controls are disabled as Xidorn says, but it sounds slightly user-hostile. Input from UX or product would help here. Adam, if you want to have a look at this? I've had luck reproducing with this video that happens to have voice and generated subtitles (shortcut is "c" otherwise it's in the controls on right right).

I'll note that Chrome doesn't seem to offer those options in a context menu, so the problem doesn't exist there. Safari however is closer to what Firefox does, and has the same bug. Sometimes websites catch the right click to offer their own menu, mitigating the problem (YouTube in particular does this.

This probably is also an issue with PiP.