demux: remove file_contents field

Only demux_cue and demux_edl used it. It's a weird field and doesn't
help with anything anymore - by now, it only saves a priv context in the
mentioned demuxers. Reducing the number of confusing things the demuxer
struct has is more important than minimizing the code.

(cherry picked from commit 082371a160)

demux/demux.c

@@ -755,7 +755,6 @@ static void demux_copy(struct demuxer *dst, struct demuxer *src)
         dst->attachments = src->attachments;
         dst->num_attachments = src->num_attachments;
         dst->matroska_data = src->matroska_data;
-        dst->file_contents = src->file_contents;
         dst->playlist = src->playlist;
         dst->seekable = src->seekable;
         dst->partially_seekable = src->partially_seekable;

demux/demux.h

@@ -212,8 +212,6 @@ typedef struct demuxer {
     int num_attachments;
 
     struct matroska_data matroska_data;
-    // for trivial demuxers which just read the whole file for codec to use
-    struct bstr file_contents;
 
     // If the file is a playlist file
     struct playlist *playlist;

demux/demux_cue.c

@@ -76,6 +76,10 @@ struct cue_track {
     struct bstr title;
 };
 
+struct priv {
+    bstr data;
+};
+
 static enum cue_command read_cmd(struct bstr *data, struct bstr *out_params)
 {
     struct bstr line = bstr_strip_linebreaks(bstr_getline(*data, data));
@@ -279,11 +283,13 @@ static double source_get_length(struct demuxer *demuxer)
 
 static void build_timeline(struct timeline *tl)
 {
+    struct priv *p = tl->demuxer->priv;
+
     void *ctx = talloc_new(NULL);
 
     add_source(tl, tl->demuxer);
 
-    struct bstr data = tl->demuxer->file_contents;
+    struct bstr data = p->data;
     data = skip_utf8_bom(data);
 
     struct cue_track *tracks = NULL;
@@ -425,8 +431,10 @@ static int try_open_file(struct demuxer *demuxer, enum demux_check check)
         if (d.len < 1 || !mp_probe_cue(d))
             return -1;
     }
-    demuxer->file_contents = stream_read_complete(s, demuxer, 1000000);
-    if (demuxer->file_contents.start == NULL)
+    struct priv *p = talloc_zero(demuxer, struct priv);
+    demuxer->priv = p;
+    p->data = stream_read_complete(s, demuxer, 1000000);
+    if (p->data.start == NULL)
         return -1;
     return 0;
 }

demux/demux_edl.c

@@ -50,6 +50,10 @@ struct tl_parts {
     int num_parts;
 };
 
+struct priv {
+    bstr data;
+};
+
 // Parse a time (absolute file time or duration). Currently equivalent to a
 // number. Return false on failure.
 static bool parse_time(bstr str, double *out_time)
@@ -288,7 +292,9 @@ static void fix_filenames(struct tl_parts *parts, char *source_path)
 
 static void build_mpv_edl_timeline(struct timeline *tl)
 {
-    struct tl_parts *parts = parse_edl(tl->demuxer->file_contents);
+    struct priv *p = tl->demuxer->priv;
+
+    struct tl_parts *parts = parse_edl(p->data);
     if (!parts) {
         MP_ERR(tl, "Error in EDL.\n");
         return;
@@ -303,19 +309,22 @@ static void build_mpv_edl_timeline(struct timeline *tl)
 
 static int try_open_file(struct demuxer *demuxer, enum demux_check check)
 {
+    struct priv *p = talloc_zero(demuxer, struct priv);
+    demuxer->priv = p;
+
     struct stream *s = demuxer->stream;
     if (s->uncached_type == STREAMTYPE_EDL) {
-        demuxer->file_contents = bstr0(s->path);
+        p->data = bstr0(s->path);
         return 0;
     }
     if (check >= DEMUX_CHECK_UNSAFE) {
         if (!bstr_equals0(stream_peek(s, strlen(HEADER)), HEADER))
             return -1;
     }
-    demuxer->file_contents = stream_read_complete(s, demuxer, 1000000);
-    if (demuxer->file_contents.start == NULL)
+    p->data = stream_read_complete(s, demuxer, 1000000);
+    if (p->data.start == NULL)
         return -1;
-    bstr_eatstart0(&demuxer->file_contents, HEADER);
+    bstr_eatstart0(&p->data, HEADER);
     return 0;
 }