2c6a3cb1f2 originally added this struct
member and then 1be863afdb later added
some more logic to loadfile that uses this. There's been more changes
since then of course, but bits using playback_short and playback_start
have mostly stayed the same. It's a bit strange it's worked this way for
so long since it makes an assumption on how long files should be and
leads to weird, broken behavior on playlists with shorter videos. The
main reason for playlist_short, as far as I can tell, is to deal with
some fringe cases with short videos and trying to go back in the
playlist. More specifically, if you use --loop=inf on a very short video
(say less than 1 second) and try to go back in the playlist, you won't
be able to without any of this special logic that deals with it. But the
current approach has several side effects like going back multiple items
in the playlist instead of just one if the video is less than one
second. This is just bad so delete everything related to playlist_short
and playlist_start.
Instead, let's handle this by keeping track of playlist-prev attempts.
Going forward in the playlist doesn't require any special handling since
a bad/broken file will just advance to the next one. So it's only going
backwards that requires some special consideration. If we're going
backwards and the user isn't using force, then mark the playlist entry
with a special flag. If the file loads successfully in
play_current_file, we can just clear the flag and not worry about it.
However if there's a failure, then we set a bool telling
play_current_file that it should go back one more item in the playlist
if possible and try again. This way, we avoid the previously mentioned
--loop=inf edgecase and the user can still attempt to retry previously
failed items in the playlist (like a url or such).
Fixes#6576, fixes#12548.