Fix #856: album dirty tracking

beets/dbcore/db.py

@@ -129,6 +129,12 @@ class Model(object):
     are subclasses of `Sort`.
     """
 
+    _always_dirty = False
+    """By default, fields only become "dirty" when their value actually
+    changes. Enabling this flag marks fields as dirty even when the new
+    value is the same as the old value (e.g., `o.f = o.f`).
+    """
+
     @classmethod
     def _getters(cls):
         """Return a mapping from field names to getter functions.
@@ -235,7 +241,7 @@ class Model(object):
         # Assign value and possibly mark as dirty.
         old_value = source.get(key)
         source[key] = value
-        if old_value != value:
+        if self._always_dirty or old_value != value:
             self._dirty.add(key)
 
     def __delitem__(self, key):

beets/library.py

@@ -702,6 +702,7 @@ class Album(LibModel):
     """
     _table = 'albums'
     _flex_table = 'album_attributes'
+    _always_dirty = True
     _fields = {
         'id':      types.PRIMARY_ID,
         'artpath': PathType(),

docs/changelog.rst

@@ -88,6 +88,9 @@ Fixes:
 * :doc:`/plugins/chroma`: Limit the number of releases and recordings fetched
   as the result of an Acoustid match to avoid extremely long processing times
   for very popular music. :bug:`1068`
+* Fix an issue where modifying an album's field without actually changing it
+  would not update the corresponding tracks to bring differing tracks back in
+  line with the album. :bug:`856`
 
 
 1.3.8 (September 17, 2014)

test/test_library.py

@@ -836,6 +836,16 @@ class AlbumInfoTest(_common.TestCase):
         self.i.remove()
         self.assertEqual(len(self.lib.albums()), 0)
 
+    def test_noop_albuminfo_changes_affect_items(self):
+        i = self.lib.items()[0]
+        i.album = 'foobar'
+        i.store()
+        ai = self.lib.get_album(self.i)
+        ai.album = ai.album
+        ai.store()
+        i = self.lib.items()[0]
+        self.assertEqual(i.album, ai.album)
+
 
 class ArtDestinationTest(_common.TestCase):
     def setUp(self):