loadfile: don't always accidentally always prefetching

demux_start_prefetch() was called unconditionally in two cases. This is
completely wrong. I'm not sure what part of my brain died off that
something this obviously wrong went in.

The prefetch case is a bit more complicated. It's a different thread, so
you can't access just access mpctx->opts there. So add an explicit field
for this, which is the simplest way to get this done. (Even if it's bad
factoring.)

Fixes: c1f1a0845e03885eebe63
Fixes: 556e204a112ee286972e5

1 files changed, 15 insertions, 11 deletions

diff --git a/player/loadfile.c b/player/loadfile.c
index 8f0d091b29..70fe0e42a7 100644
--- a/player/loadfile.c
+++ b/player/loadfile.c
@@ -983,13 +983,15 @@ static void *open_demux_thread(void *ctx)
     if (demux) {
         MP_VERBOSE(mpctx, "Opening done: %s\n", mpctx->open_url);
 
-        int num_streams = demux_get_num_stream(demux);
-        for (int n = 0; n < num_streams; n++) {
-            struct sh_stream *sh = demux_get_stream(demux, n);
-            demuxer_select_track(demux, sh, MP_NOPTS_VALUE, true);
-        }
+        if (mpctx->open_for_prefetch && !demux->fully_read) {
+            int num_streams = demux_get_num_stream(demux);
+            for (int n = 0; n < num_streams; n++) {
+                struct sh_stream *sh = demux_get_stream(demux, n);
+                demuxer_select_track(demux, sh, MP_NOPTS_VALUE, true);
+            }
 
-        demux_start_prefetch(demux);
+            demux_start_prefetch(demux);
+        }
     } else {
         MP_VERBOSE(mpctx, "Opening failed or was aborted: %s\n", mpctx->open_url);
 
@@ -1026,7 +1028,8 @@ static void cancel_open(struct MPContext *mpctx)
 }
 
 // Setup all the field to open this url, and make sure a thread is running.
-static void start_open(struct MPContext *mpctx, char *url, int url_flags)
+static void start_open(struct MPContext *mpctx, char *url, int url_flags,
+                       bool for_prefetch)
 {
     cancel_open(mpctx);
 
@@ -1039,6 +1042,7 @@ static void start_open(struct MPContext *mpctx, char *url, int url_flags)
     mpctx->open_url = talloc_strdup(NULL, url);
     mpctx->open_format = talloc_strdup(NULL, mpctx->opts->demuxer_name);
     mpctx->open_url_flags = url_flags;
+    mpctx->open_for_prefetch = for_prefetch;
     if (mpctx->opts->load_unsafe_playlists)
         mpctx->open_url_flags = 0;
 
@@ -1075,7 +1079,7 @@ static void open_demux_reentrant(struct MPContext *mpctx)
     }
 
     if (!mpctx->open_active)
-        start_open(mpctx, url, mpctx->playing->stream_flags);
+        start_open(mpctx, url, mpctx->playing->stream_flags, false);
 
     // User abort should cancel the opener now.
     mp_cancel_set_parent(mpctx->open_cancel, mpctx->playback_abort);
@@ -1106,7 +1110,7 @@ void prefetch_next(struct MPContext *mpctx)
     struct playlist_entry *new_entry = mp_next_file(mpctx, +1, false, false);
     if (new_entry && !mpctx->open_active && new_entry->filename) {
         MP_VERBOSE(mpctx, "Prefetching: %s\n", new_entry->filename);
-        start_open(mpctx, new_entry->filename, new_entry->stream_flags);
+        start_open(mpctx, new_entry->filename, new_entry->stream_flags, true);
     }
 }
 
@@ -1553,9 +1557,9 @@ static void play_current_file(struct MPContext *mpctx)
         goto terminate_playback;
     }
 
-    demux_start_prefetch(mpctx->demuxer);
-
     if (opts->demuxer_cache_wait) {
+        demux_start_prefetch(mpctx->demuxer);
+
         while (!mpctx->stop_play) {
             struct demux_reader_state s;
             demux_get_reader_state(mpctx->demuxer, &s);