Fix #1896 (bungled fix to #1895)

beets/mediafile.py

@@ -215,9 +215,9 @@ def _sc_decode(soundcheck):
     used by ReplayGain.
     """
     # We decode binary data. If one of the formats gives us a text
-    # string, guess that it's UTF-8.
+    # string, interpret it as UTF-8.
     if isinstance(soundcheck, unicode):
-        soundcheck = soundcheck.decode('utf8')
+        soundcheck = soundcheck.encode('utf8')
 
     # SoundCheck tags consist of 10 numbers, each represented by 8
     # characters of ASCII hex preceded by a space.

test/test_mediafile_edge.py

@@ -313,6 +313,13 @@ def test_special_characters(self):
         self.assertEqual(gain, 0.0)
         self.assertEqual(peak, 0.0)
 
+    def test_decode_handles_unicode(self):
+        # Most of the time, we expect to decode the raw bytes. But some formats
+        # might give us text strings, which we need to handle.
+        gain, peak = beets.mediafile._sc_decode(u'caf\xe9')
+        self.assertEqual(gain, 0.0)
+        self.assertEqual(peak, 0.0)
+
 
 class ID3v23Test(unittest.TestCase, TestHelper):
     def _make_test(self, ext='mp3', id3v23=False):