downloadbuffer: Deadlocks when handling non-flushing seek
Originally filed in https://bugs.webkit.org/show_bug.cgi?id=260796
In WebKit when the player is configured for looping videos, it performs a non-flushing segment seek back to position 0. This can lead to downloadbuffer waiting forever for a download to complete. There is code in place to unlock the getrange() (pull mode) when the element receives a flush-start, but that's not triggered when there's no flush.
So I think downloadbuffer should also unlock its getrange() when it receives segment seek on its src pad?