options: add --playlist-inherit-options option

This allows controlling whether the files in a playlist inherit the
per-file options of the playlist file itself. For playlists created
by --autocreate-playlist, --playlist-inherit-options=current allows
inheriting only for the item the playlist is created from.

Author: na-na-hi

DOCS/interface-changes/playlist-inherit-options.txt

@@ -0,0 +1 @@
+add `--playlist-inherit-options` option

DOCS/man/options.rst

@@ -335,6 +335,12 @@ Playback Control
         local files, such as special protocols like ``avdevice://`` (which are
         inherently unsafe).
 
+``--playlist-inherit-options=<yes|no|current>``
+    Whether the per-file options of a playlist file are inherited by its items
+    when the playlist file is resolved and expanded (default: no). The value
+    ``current`` means that for playlists created by ``--autocreate-playlist``,
+    only the file from which the playlist is created inherits the options.
+
 ``--chapter-merge-threshold=<number>``
     Threshold for merging almost consecutive ordered chapter parts in
     milliseconds (default: 100). Some Matroska files with ordered chapters

options/options.c

@@ -617,6 +617,8 @@ static const m_option_t mp_opts[] = {
 
     {"playlist-start", OPT_CHOICE(playlist_pos, {"auto", -1}, {"no", -1}),
         M_RANGE(0, INT_MAX)},
+    {"playlist-inherit-options", OPT_CHOICE(playlist_inherit_options,
+        {"no", 0}, {"yes", 1}, {"current", 2})},
 
     {"pause", OPT_BOOL(pause)},
     {"keep-open", OPT_CHOICE(keep_open,

options/options.h

@@ -283,6 +283,7 @@ typedef struct MPOpts {
     char **input_commands;
     bool consolecontrols;
     int playlist_pos;
+    int playlist_inherit_options;
     struct m_rel_time play_start;
     struct m_rel_time play_end;
     struct m_rel_time play_length;

player/loadfile.c

@@ -1142,8 +1142,10 @@ static void transfer_playlist(struct MPContext *mpctx, struct playlist *pl,
         struct playlist_entry *new = pl->current;
         struct playlist_entry *current = mpctx->playlist->current;
         *num_new_entries = pl->num_entries;
-        if (current)
+        if (current && mpctx->opts->playlist_inherit_options == 1)
             playlist_set_params(pl, current->params, current->num_params);
+        else if (current && new && mpctx->opts->playlist_inherit_options == 2)
+            playlist_entry_add_params(new, current->params, current->num_params);
         *start_id = playlist_transfer_entries(mpctx->playlist, pl);
         // current entry is replaced
         if (current)