[gnome-music/wip/jfelder/mpris-cleanup: 2/25] mpris: Only set trackNumber metadata when it's available

[Jean Felder <jfelder src gnome org>]

commit 065c5e5e63e82abd45757d832b162d7fae5b4ca9
Author: Jean Felder <jfelder src gnome org>
Date:   Fri Jun 14 09:21:50 2019 +0200

    mpris: Only set trackNumber metadata when it's available
    
    The get_track_number method from Grl.Media returns zero when the track
    number is unknown. In that case, the trackNumber metadata should not
    be sent.

 gnomemusic/mpris.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/gnomemusic/mpris.py b/gnomemusic/mpris.py
index af60ce57..86f5aa14 100644
--- a/gnomemusic/mpris.py
+++ b/gnomemusic/mpris.py
@@ -301,7 +301,6 @@ class MediaPlayer2Service(Server):
             'mpris:trackid': GLib.Variant('o', song_dbus_path),
             'xesam:url': GLib.Variant('s', media.get_url()),
             'mpris:length': GLib.Variant('x', length),
-            'xesam:trackNumber': GLib.Variant('i', media.get_track_number()),
             'xesam:useCount': GLib.Variant('i', media.get_play_count()),
             'xesam:userRating': GLib.Variant('d', user_rating),
             'xesam:title': GLib.Variant('s', utils.get_media_title(media)),
@@ -319,6 +318,10 @@ class MediaPlayer2Service(Server):
             last_played_str = last_played.format("%FT%T%:z")
             metadata['xesam:lastUsed'] = GLib.Variant('s', last_played_str)
 
+        track_nr = media.get_track_number()
+        if track_nr > 0:
+            metadata['xesam:trackNumber'] = GLib.Variant('i', track_nr)
+
         # If the media has already been part of an MPRIS playlist, its
         # thumbnail is already set. Otherwise, try to look for it in the
         # cache directory and set the media thumbnail for a future use.