get original release date for MB release group (#65)

beets/autotag/mb.py

@@ -68,6 +68,16 @@ def track_info(recording):
 
     return info
 
+def _set_date_str(info, date_str):
+    """Given a (possibly partial) YYYY-MM-DD string and an AlbumInfo
+    object, set the object's release date fields appropriately.
+    """
+    if date_str:
+        date_parts = date_str.split('-')
+        for key in ('year', 'month', 'day'):
+            if date_parts:
+                setattr(info, key, int(date_parts.pop(0)))
+
 def album_info(release):
     """Takes a MusicBrainz release result dictionary and returns a beets
     AlbumInfo object containing the interesting data about that release.
@@ -94,13 +104,12 @@ def album_info(release):
         info.albumtype = reltype.lower()
 
     # Release date.
-    if 'date' in release: # XXX: when is this not included?
-        date_str = release['date']
-        if date_str:
-            date_parts = date_str.split('-')
-            for key in ('year', 'month', 'day'):
-                if date_parts:
-                    setattr(info, key, int(date_parts.pop(0)))
+    if 'first-release-date' in release['release-group']:
+        # Try earliest release date for the entire group first.
+        _set_date_str(info, release['release-group']['first-release-date'])
+    elif 'date' in release:
+        # Fall back to release-specific date.
+        _set_date_str(info, release['date'])
 
     # Label name.
     if release.get('label-info-list'):

docs/changelog.rst

@@ -18,6 +18,8 @@ Changelog
 * The :doc:`/plugins/replaygain`, written by `Peter Brunner`_, has been merged
   into the core beets distribution. Use it to analyze audio and adjust playback
   levels in ReplayGain-aware music players.
+* Albums are now tagged with their *original* release date rather than the date
+  of any reissue, remaster, "special edition", or the like.
 * When entering an ID manually during tagging, beets now searches for anything
   that looks like an MBID in the entered string. This means that full
   MusicBrainz URLs now work as IDs at the prompt. (Thanks to derwin.)

test/test_mb.py

@@ -24,11 +24,14 @@ class MBAlbumInfoTest(unittest.TestCase):
         release = {
             'title': 'ALBUM TITLE',
             'id': 'ALBUM ID',
-            'release-group': {'type': 'Album'},
+            'release-group': {
+                'type': 'Album',
+                'first-release-date': date_str,
+            },
             'artist-credit': [
                 {'artist': {'name': 'ARTIST NAME', 'id': 'ARTIST ID'}}
             ],
-            'date': date_str,
+            'date': '3001',
             'medium-list': [],
         }
         if tracks: