Bug 175434 – WebRTC MediaStream created without tracks does not update active state after tracks are added

• Component: WebRTC
• Status: RESOLVED FIXED

Created attachment 317827 [details]
javascript test to illustrate the bug

Summary:
When a new MediaStream is created manually, its "active" field is set to false (which is correct).  However, after adding an active track to the stream, its "active" field is not updated, and remains false.  It should update to reflect the state of its tracks.

Steps to Reproduce:
1) Create a MediaStream with a video track via getUserMedia ("ms1")
2) Create a new MediaStream manually (via something like "var ms2 = new MediaStream()"
3) Do: ms2.addTrack(ms1.getVideoTracks()[0]);

Expected Results:
ms2 should be active ("active: true")

Observed Results:
ms2 isn't active ("active: false")

Version:
Release 35 (Safari 11.0, WebKit 12604.1.29)

Notes:
Attached a simple example html file that reproduces the issue

Configuration:
This is running on a macbook, running Sierra 10.12.5 (16F73)

[youenn fablet]

rdar://problem/33358476

[youenn fablet]

Thanks for filing this bug.
So you only rely on the active attribute, not on any event that would be sent if the active attribute value is changing, right?

i don't think we rely on any event, what i was running into was tests on the 'active' member failing, so that would at least let me get past where i was stuck.

hey youenn, any idea when this will be fixed in tech preview?

[youenn fablet]

Created attachment 319204 [details]
Patch

[Eric Carlson]

Comment on attachment 319204 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=319204&action=review

> LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-clone-track-expected.txt:2
> +FAIL check clone track after captureStream() cloned_track.requestFrame is not a function. (In 'cloned_track.requestFrame()', 'cloned_track.requestFrame' is undefined)

This seems wrong.

[youenn fablet]

(In reply to Eric Carlson from comment #6)
> Comment on attachment 319204 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=319204&action=review
> 
> > LayoutTests/fast/mediacapturefromelement/CanvasCaptureMediaStream-clone-track-expected.txt:2
> > +FAIL check clone track after captureStream() cloned_track.requestFrame is not a function. (In 'cloned_track.requestFrame()', 'cloned_track.requestFrame' is undefined)
> 
> This seems wrong.

I filed https://bugs.webkit.org/show_bug.cgi?id=176036

[WebKit Commit Bot]

Comment on attachment 319204 [details]
Patch

Clearing flags on attachment: 319204

Committed r221277: <http://trac.webkit.org/changeset/221277>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.