This is what the spec mandates. The spec doesn't say anything about
updating duration when it had been previously set, even if the new
init segment says that the duration is growing.
This fixes MSE YTTV 2018 69.MediaSourceDurationVP9.
Original patch by Enrique Ocaña González.
Created attachment 350462 [details]
Link to the spec: https://www.w3.org/TR/media-source/#sourcebuffer-init-segment-received
Comment on attachment 350462 [details]
Clearing flags on attachment: 350462
Committed r236395: <https://trac.webkit.org/changeset/236395>
All reviewed patches have been landed. Closing bug.