demux: disable backward demuxing if it fatally fails

We don't care much about this case, because backward playback can fail
terribly without a good way to detect it, so this was fine.

However, this froze in certain situations. Reading from a subtitle file
for which backward demuxing failed could make it get stuck in
demux_read_packet_async() in unthreaded mode. (That we don't support
backwards subtitle decoding anyway doesn't matter for this.)

So aggressively disable backward demuxing to prevent worse in these
situations. The behavior will still be awful, because the frontend is
still in backwards playback mode, but at least it won't freeze.

0 files changed, 0 insertions, 0 deletions