fix broken symlink crash (#157)

NEWS

@@ -41,7 +41,8 @@
 * 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.
+* Fix a bug with old versions of the Monkey's Audio format.
+* Fix a crash on broken symbolic links.
 * Retry in more cases when MusicBrainz servers are slow/overloaded.
 * The old "albumify" plugin for upgrading databases was removed.
 

beets/mediafile.py

@@ -495,6 +495,8 @@ class MediaFile(object):
             self.mgfile = mutagen.File(path)
         except unreadable_exc:
             raise UnreadableFileError('Mutagen could not read file')
+        except IOError:
+            raise UnreadableFileError('could not read file')
 
         if self.mgfile is None: # Mutagen couldn't guess the type
             raise FileTypeError('file type unsupported by Mutagen')

test/test_mediafile.py

@@ -130,6 +130,15 @@ class SafetyTest(unittest.TestCase):
         self._exccheck('nothing.xml', beets.mediafile.UnreadableFileError,
                        "ftyp")
 
+    def test_broken_symlink(self):
+        fn = os.path.join('rsrc', 'brokenlink')
+        os.symlink('does_not_exist', fn)
+        try:
+            self.assertRaises(beets.mediafile.UnreadableFileError,
+                              beets.mediafile.MediaFile, fn)
+        finally:
+            os.unlink(fn)
+
 class SideEffectsTest(unittest.TestCase):
     def setUp(self):
         self.empty = os.path.join('rsrc', 'empty.mp3')