1841404 - When multiple windows with video players (e.g., YouTube windows) are fullscreened on MacOS Desktop with the MacOS fullscreen API enabled, un-fullscreening one window un-fullscreens all other fullscreened windows.

Status: RESOLVED DUPLICATE of bug 1621736

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

Description

[slayerdragon999999]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/114.0

Steps to reproduce:

1. Set the full-screen-api.macos-native-full-screen config to true.
2. Open a new window (Window A), pick a YouTube video, and fullscreen the window via YouTube's video player (i.e., not the window/browser fullscreen feature, though both yield the same result).
3. Open a second window (Window B), pick a YouTube video, and fullscreen the window via YouTube's video player (i.e., not the window/browser fullscreen feature, tough both yield the same result).
4. Close Window A's fullscreened video player via the Escape key.
5. Observe that Window B's fullscreened video player also closes. Additionally, when trying to re-fullscreen Window A, it does not adhere to the native MacOS fullscreen API, and instead fullscreens into a windowed mode of sorts.

Actual results:

When two windows each containing video players are fullscreened, and one window is un-fullscreened, the other window is also un-fullscreened.

Additionally, the first fullscreened window does not re-fullscreen the same way, and instead only fullscreens to a windowed fullscreen mode of sorts (different than that of the native MacOS fullscreen API).

Expected results:

When two windows each containing video players are fullscreened, and one window is un-fullscreened, the other window should remain in fullscreen. Additionally, the un-fullscreened window should be able to re-fullscreen via the native MacOS fullscreen API.

Comment 1

[slayerdragon999999]

Super quick follow-up! The user-agent in this report has Firefox 114.0, but I also tested this on the Beta build (115.0) and the Nightly build (116.0), all of which yielded the same output.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::DOM: Core & HTML' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 3

[slayerdragon999999]

Attachment: Firefox Fullscreen MacOS Bug 480 Shortened.mov

Video shows opening two windows each containing a YouTube video player, fullscreening each, un-fullscreening one, and demonstrating that the other window is also un-fullscreened. Finally, the video shows that the windows do not respond correctly to being re-fullscreened.

Comment 4

[slayerdragon999999]

One additional note I'd like to add is that on Google Chrome, this set of steps is handled correctly, whereby the entire window is brought into a separate space in Mission Control, and un-fullscreening one window leaves the others in Mission Control.

Similarly, in Safari, the fullscreen portion is brought into a separate space in Mission Control while the window itself remains visible/tabble/accessible.

Ideally, fixing this would adhere to Google Chrome's method as this bug is fixed, especially since Firefox already brings the full window into a separate space in Mission Control when a window is fullscreened via the MacOS native fullscreen API.