loadfile: discard prefetched files if demuxer options changed

When using --prefetch-playlist, if demuxer options are changed in the
time window between the start of prefetching and the playback of the
next file, the old values are used. This includes setting demuxer
options in legacy extension auto profiles.

Fix this by setting a flag when demuxer options change and not using the
prefetched data when that flag is true.

UPDATE_DEMUXER is not added to demux.c's options because those already
support updates while playing.

demux/cache.c

@@ -50,6 +50,7 @@ const struct m_sub_options demux_cache_conf = {
     .defaults = &(const struct demux_cache_opts){
         .unlink_files = 2,
     },
+    .change_flags = UPDATE_DEMUXER,
 };
 
 struct demux_cache {

demux/demux_lavf.c

@@ -121,6 +121,7 @@ const struct m_sub_options demux_lavf_conf = {
         .linearize_ts = -1,
         .propagate_opts = true,
     },
+    .change_flags = UPDATE_DEMUXER,
 };
 
 struct format_hack {

demux/demux_libarchive.c

@@ -116,5 +116,6 @@ const struct demuxer_desc demuxer_desc_libarchive = {
             {0}
         },
         .size = sizeof(OPT_BASE_STRUCT),
+        .change_flags = UPDATE_DEMUXER,
     },
 };

demux/demux_mkv.c

@@ -257,6 +257,7 @@ const struct m_sub_options demux_mkv_conf = {
         .subtitle_preroll_secs_index = 10.0,
         .probe_start_time = true,
     },
+    .change_flags = UPDATE_DEMUXER,
 };
 
 #define REALHEADER_SIZE    16

demux/demux_playlist.c

@@ -77,6 +77,7 @@ struct m_sub_options demux_playlist_conf = {
             "video", "audio", "image", "archive", "playlist", NULL
         },
     },
+    .change_flags = UPDATE_DEMUXER,
 };
 
 static bool check_mimetype(struct stream *s, const char *const *list)

demux/demux_raw.c

@@ -85,6 +85,7 @@ const struct m_sub_options demux_rawaudio_conf = {
         .samplerate = 44100,
         .aformat = PCM(1, 0, 16, 0), // s16le
     },
+    .change_flags = UPDATE_DEMUXER,
 };
 
 #undef PCM

options/m_option.h

@@ -443,7 +443,8 @@ char *format_file_size(int64_t size);
 #define UPDATE_VIDEO            (1 << 15)  // force redraw if needed
 #define UPDATE_VO               (1 << 16)  // reinit the VO
 #define UPDATE_CLIPBOARD        (1 << 17)  // reinit the clipboard
-#define UPDATE_OPT_LAST         (1 << 17)
+#define UPDATE_DEMUXER          (1 << 18)  // invalidate --prefetch-playlist's data
+#define UPDATE_OPT_LAST         (1 << 18)
 
 // All bits between of UPDATE_ flags
 #define UPDATE_OPTS_MASK        ((UPDATE_OPT_LAST << 1) - 1)

options/options.c

@@ -627,7 +627,7 @@ static const m_option_t mp_opts[] = {
 #endif
 
     // demuxer.c - select audio/sub file/demuxer
-    {"demuxer", OPT_STRING(demuxer_name), .help = demuxer_help},
+    {"demuxer", OPT_STRING(demuxer_name), .help = demuxer_help, .flags = UPDATE_DEMUXER},
     {"audio-demuxer", OPT_STRING(audio_demuxer_name), .help = demuxer_help},
     {"sub-demuxer", OPT_STRING(sub_demuxer_name), .help = demuxer_help},
     {"demuxer-thread", OPT_BOOL(demuxer_thread)},

player/command.c

@@ -7741,6 +7741,9 @@ void mp_option_change_callback(void *ctx, struct m_config_option *co, int flags,
             mpctx->stop_play = PT_CURRENT_ENTRY;
     }
 
+    if (flags & UPDATE_DEMUXER)
+        mpctx->demuxer_changed = true;
+
     if (opt_ptr == &opts->vo->android_surface_size) {
         if (mpctx->video_out)
             vo_control(mpctx->video_out, VOCTRL_EXTERNAL_RESIZE, NULL);

player/core.h

@@ -463,6 +463,7 @@ typedef struct MPContext {
     char *open_format;
     int open_url_flags;
     bool open_for_prefetch;
+    bool demuxer_changed;
     // --- All fields below are owned by open_thread, unless open_done was set
     //     to true.
     struct demuxer *open_res_demuxer;

player/loadfile.c

@@ -1180,6 +1180,7 @@ static void start_open(struct MPContext *mpctx, char *url, int url_flags,
     mpctx->open_format = talloc_strdup(NULL, mpctx->opts->demuxer_name);
     mpctx->open_url_flags = url_flags;
     mpctx->open_for_prefetch = for_prefetch && mpctx->opts->demuxer_thread;
+    mpctx->demuxer_changed = false;
 
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     // Don't allow to open local paths or stdin during fuzzing
@@ -1210,16 +1211,23 @@ static void open_demux_reentrant(struct MPContext *mpctx)
         bool failed = done && !mpctx->open_res_demuxer;
         bool correct_url = strcmp(mpctx->open_url, url) == 0;
 
-        if (correct_url && !failed) {
+        if (correct_url && !mpctx->demuxer_changed && !failed) {
             MP_VERBOSE(mpctx, "Using prefetched/prefetching URL.\n");
-        } else if (correct_url && failed) {
-            MP_VERBOSE(mpctx, "Prefetched URL failed, retrying.\n");
-            cancel_open(mpctx);
         } else {
-            if (done) {
-                MP_VERBOSE(mpctx, "Dropping finished prefetch of wrong URL.\n");
+            if (correct_url && failed) {
+                MP_VERBOSE(mpctx, "Prefetched URL failed, retrying.\n");
+            } else if (mpctx->demuxer_changed) {
+                if (done) {
+                    MP_VERBOSE(mpctx, "Dropping finished prefetch because demuxer options changed.\n");
+                } else {
+                    MP_VERBOSE(mpctx, "Aborting ongoing prefetch because demuxer options changed.\n");
+                }
             } else {
-                MP_VERBOSE(mpctx, "Aborting ongoing prefetch of wrong URL.\n");
+                if (done) {
+                    MP_VERBOSE(mpctx, "Dropping finished prefetch of wrong URL.\n");
+                } else {
+                    MP_VERBOSE(mpctx, "Aborting ongoing prefetch of wrong URL.\n");
+                }
             }
             cancel_open(mpctx);
         }