DBus control: do not query index of item if known

The track index is sometimes known when serialising a track's metadata.
This moves the index query outside the metadata serialisation function
when necessary.

modules/control/dbus/dbus.c

@@ -1311,7 +1311,7 @@ int DemarshalSetPropertyValue( DBusMessage *p_msg, void *p_arg )
         free( psz ); \
     }
 
-int GetInputMeta(vlc_playlist_t *playlist, vlc_playlist_item_t *item, DBusMessageIter *args)
+int GetInputMeta(size_t index, vlc_playlist_item_t *item, DBusMessageIter *args)
 {
     input_item_t *p_input = vlc_playlist_item_GetMedia(item);
     DBusMessageIter dict, dict_entry, variant, list;
@@ -1322,8 +1322,7 @@ int GetInputMeta(vlc_playlist_t *playlist, vlc_playlist_item_t *item, DBusMessag
     dbus_int64_t i_length = i_mtime / 1000;
     char *psz_trackid;
 
-    if (asprintf(&psz_trackid, MPRIS_TRACKID_FORMAT,
-                 vlc_playlist_IndexOf(playlist, item)) == -1)
+    if (asprintf(&psz_trackid, MPRIS_TRACKID_FORMAT, index) == -1)
         return VLC_ENOMEM;
 
     const char* ppsz_meta_items[] =

modules/control/dbus/dbus_common.h

@@ -144,7 +144,7 @@ enum
 };
 
 int DemarshalSetPropertyValue( DBusMessage *p_msg, void *p_arg );
-int GetInputMeta( vlc_playlist_t *, vlc_playlist_item_t *,
+int GetInputMeta( size_t index, vlc_playlist_item_t *,
                   DBusMessageIter *args );
 int AddProperty ( intf_thread_t *p_intf,
                   DBusMessageIter *p_container,

modules/control/dbus/dbus_player.c

@@ -525,13 +525,20 @@ static int
 MarshalMetadata( intf_thread_t *p_intf, DBusMessageIter *container )
 {
     int result = VLC_SUCCESS;
+
+    vlc_playlist_item_t *plitem = NULL;
     vlc_playlist_t *playlist = p_intf->p_sys->playlist;
     vlc_playlist_Lock(playlist);
     ssize_t id = vlc_playlist_GetCurrentIndex(playlist);
-    if(id != -1)
+    if (id != -1) {
+        plitem = vlc_playlist_Get(playlist, id);
+        vlc_playlist_item_Hold(plitem);
+    }
+    vlc_playlist_Unlock(playlist);
+    if(plitem)
     {
-        vlc_playlist_item_t *plitem = vlc_playlist_Get(playlist, id);
-        result = GetInputMeta(playlist, plitem, container);
+        result = GetInputMeta(id, plitem, container);
+        vlc_playlist_item_Release(plitem);
     }
     else
     {   // avoid breaking the type marshalling
@@ -541,7 +548,6 @@ MarshalMetadata( intf_thread_t *p_intf, DBusMessageIter *container )
             !dbus_message_iter_close_container( container, &a ) )
             result = VLC_ENOMEM;
     }
-    vlc_playlist_Unlock(playlist);
     return result;
 }
 

modules/control/dbus/dbus_tracklist.c

@@ -132,13 +132,20 @@ DBUS_METHOD( GetTracksMetadata )
 
         vlc_playlist_Lock(playlist);
         bool id_valid = i_track_id < vlc_playlist_Count(playlist);
+        vlc_playlist_item_t *item = NULL;
         if (id_valid)
         {
-            vlc_playlist_item_t *item = vlc_playlist_Get(playlist, i_track_id);
-            GetInputMeta(playlist, item, &meta);
+            item = vlc_playlist_Get(playlist, i_track_id);
+            vlc_playlist_item_Hold(item);
         }
         vlc_playlist_Unlock(playlist);
-        if (!id_valid)
+
+        if (id_valid)
+        {
+            GetInputMeta(i_track_id, item, &meta);
+            vlc_playlist_item_Release(item);
+        }
+        else
         {
 invalid_track_id:
             msg_Err( (vlc_object_t*) p_this, "Invalid track id: %s",