demux_mkv, stream: attempt to improve behavior in unseekable streams

stream_skip() semantics were kind of bad, especially after the recent
change to the stream code. Forward stream_skip() calls could still
trigger a seek and fail, even if it was supposed to actually skip data.
(Maybe the idea that stream_skip() should try to seek is worthless in
the first place.)

Rename it to stream_seek_skip() (takes absolute position now because I
think that's better), and make it always skip if the stream is marked as
forward.

While we're at it, make EOF detection more robust. I guess s->eof
shouldn't exist at all, since it's valid only "sometimes". It should be
removed... but not today. A 1-byte stream_read_peek() call is good to
get the s->eof flag set to a correct value.

1 files changed, 1 insertions, 1 deletions

diff --git a/demux/demux_playlist.c b/demux/demux_playlist.c
index a7650b2b69..b51edad86c 100644
--- a/demux/demux_playlist.c
+++ b/demux/demux_playlist.c
@@ -99,7 +99,7 @@ static int read_characters(stream_t *s, uint8_t *dst, int dstsize, int utf16)
         if (len > dstsize)
             return -1; // line too long
         memcpy(dst, buf, len);
-        stream_skip(s, len);
+        stream_seek_skip(s, len);
         return len;
     }
 }