fix crasher w/ old APE files (#159)

NEWS

@@ -41,6 +41,7 @@
 * Fix a bug where some files would be erroneously interpreted as MP4.
 * Fix permission bits applied to album art files.
 * Fix malformed MusicBrainz queries caused by null characters.
+# Fix a bug with old versions of the Monkey's Audio format.
 * Retry in more cases when MusicBrainz servers are slow/overloaded.
 * The old "albumify" plugin for upgrading databases was removed.
 

beets/mediafile.py

@@ -715,10 +715,14 @@ class MediaFile(object):
     @property
     def bitrate(self):
         if self.type in ('flac', 'ape'):
+            if hasattr(self.mgfile.info, 'bits_per_sample'):
                 # Simulate bitrate for lossless formats.
                 #fixme: The utility of this guess is questionable.
                 return self.mgfile.info.sample_rate * \
                        self.mgfile.info.bits_per_sample
+            else:
+                # Old APE file format.
+                return 0
         elif self.type == 'wv':
             # Mutagen doesn't provide enough information.
             return 0

test/test_mediafile.py

@@ -63,6 +63,10 @@ class EdgeTest(unittest.TestCase):
         self.assertEqual(f.disc, 4)
         self.assertEqual(f.disctotal, 5)
 
+    def test_old_ape_version_bitrate(self):
+        f = beets.mediafile.MediaFile(os.path.join('rsrc', 'oldape.ape'))
+        self.assertEqual(f.bitrate, 0)
+
 _sc = beets.mediafile._safe_cast
 class InvalidValueToleranceTest(unittest.TestCase):
     def test_packed_integer_with_extra_chars(self):