1744398 - Media element load algorithm must fire 'emptied' BEFORE 'timeupdate'

Status: RESOLVED FIXED

(Core :: Audio/Video, defect, P4)

Description

[wofwca]

Steps to reproduce:

1. Make a media element play (e.g. https://www.w3schools.com/html/mov_bbb.mp4).
2. Attach 'emptied' and 'timeupdate' event listeners to it.

v = document.querySelector('video');
v.addEventListener('emptied', console.log);
v.addEventListener('timeupdate', console.log);

3. Change the source of the element.

v.src = '';

Actual results:

As you see in the console, 'timeupdate' event got fired before the 'emptied' event

Expected results:

'emptied' must have been fired before 'timeupdate', as the spec states.

Comment 1

[wofwca]

Here's what I believe to be the responsible code: https://github.com/mozilla/gecko-dev/blob/e24f563e9e5b9580dbcda1b114ceb202162026f2/dom/html/HTMLMediaElement.cpp#L2306-L2333

And I believe

Comment 2

[wofwca]

that fixing it is just a matter of moving the DispatchAsyncEvent(u"emptied"_ns); line to the top of the if block.
And I would like to try to fix this myself. As soon as I catch up to the contributing documentation.

Comment 3

[Jon Bauman [:jbauman:]]

Thanks for your interest, wofwca! Alastor, would you be a good person to advise on this?

Comment 4

[Alastor Wu [:alwu]]

Yes, according to the spec, it looks like you can simply move the empty to the top line of that if block. Feel free to set review flag on me, and feel free to NI me if you have any question about the contribution.

Thank you so much.

Comment 5

[az [:az]]

Attachment: Bug 1744398 - Media element load algorithm must fire 'emptied' before 'timeupdate' r=alwu

Comment 6

[az [:az]]

Attachment: Bug 1744398 - Test if media element receives 'emptied' before 'timeupdate' r=alwu

Depends on D142628

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/392a29b950a5
Media element load algorithm must fire 'emptied' before 'timeupdate' r=alwu
https://hg.mozilla.org/integration/autoland/rev/4e24b1d12558
Test if media element receives 'emptied' before 'timeupdate' r=alwu

Comment 8

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/33474 for changes under testing/web-platform/tests

Comment 9

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/392a29b950a5
https://hg.mozilla.org/mozilla-central/rev/4e24b1d12558

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot