Found in

• Firefox Nightly 114.0a1 (2023-05-04)

Affected versions

• Firefox Nightly 114.0a1
• Firefox 113.0 RC

Affected platforms

• macOS 12 (both x86 and aarch64)
• Windows 10/11
• Windows 7
• Ubuntu 22.04

Steps to reproduce

1. Open: http://tinyurl.com/zdxp4lu.
2. Double-click on a free spot of the player (e.g. on the time counter)
3. Double-click on the same spot or press Esc
4. Observe the player

Expected result

• The player should still be visible

Actual result

• The player becomes invisible when entering full-screen and stays so until refreshing the page
• Not sure if the audio player should have a full-screen function. Other audio players do not have (e.g. Google Chrome audio player).

Regression range
I will check for the regression range ASAP. The issue is also reproducible on Firefox 110.0 RC.

Notes

• This issue happens on audio files that can be played through the browser (aac, ogg, mp3, flac etc.)

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=9a6fed87ccdb08caa98520bc8cbafba2ef1ccf1e&tochange=ab533ecb02432dbb8dc5353879dac56b21ee1943

Set release status flags based on info from the regressing bug 1793889

Set release status flags based on info from the regressing bug 1793889

Mike, do you know what's up here - or why we even allow full screen for poster-less audio-only files? I tried to figure this out previously in bug 1799092 but didn't really get anywhere, and at the time decided it wasn't worth pursuing... to me, the comments in that bug read like the media folks felt it was up to frontend to decide whether this should be supported, so I'm not sure wontfix was the right decision there.

I mean, tbf, I also don't understand why the player would be hidden after returning from fullscreen... perhaps we're hitting https://searchfox.org/mozilla-central/rev/1f0f0e29a7bcb6d6dc82fe628861bccc2066a98e/toolkit/content/widgets/videocontrols.js#1754-1756 and isVideoInFullScreen is 'wrong' and still true?

or why we even allow full screen for poster-less audio-only files?

Pretty odd. I can imagine someone might want to maybe pip an audio player to get always-available-controls for it, but fullscreening doesn't make a whole lot of sense to me.

So yeah, I think this is a bug.

Bug 1776222 is actually remarkably similar to this, and this is one that was fixed by the patch the caused the regression bug 1793889, which is reported as the regression for this bug. The difference being that that first bug (bug 1776222) was about fullscreening an <audio> element, which thankfully hasn't regressed.

So I suspect what we have here is just a case that we didn't test properly - an audio-only <video> tag.