trackdb: Register the save functions after loading

We replace each object after unpickling, so we need to make sure we
listen to the new ones when they tell us they've changed.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

test_trackdb.py

@@ -130,6 +130,10 @@ class TestTrackDB(unittest.TestCase):
         self.assertEqual(len(trackdb.tags.Decade), 2)
         self.assertEqual(len(trackdb.tags.Year), 2)
 
+        self.assertIn(trackdb.save, trackdb.Library.Added.subscribers)
+        self.assertIn(trackdb.save, trackdb.Tracks.Added.subscribers)
+        self.assertIn(trackdb.save, trackdb.tags.User.Added.subscribers)
+
     def test_trackdb_stress(self):
         lib = trackdb.Library.add(pathlib.Path("./trier/Test Library/"))
         lib.scan().join()

trackdb/__init__.py

@@ -81,6 +81,7 @@ def load():
             tags.set_state(*tagstate)
             Tracks.load_tags()
             Library.fix_tracks()
+            __register_callbacks()
 
 def __register_callbacks():
     for store in [ Library, tags.User, Tracks ]: