playlists: Make move from/to same index a no-op

Fixes #175

docs/changelog.rst

@@ -2,6 +2,16 @@
 Changelog
 *********
 
+
+v2.0.3 (UNRELEASED)
+===================
+
+Bug fix release.
+
+- Make moving a playlist to its own location a no-op instead of causing an
+  error like libspotify does. (Fixes: :issue:`175`)
+
+
 v2.0.2 (2015-08-06)
 ===================
 

spotify/playlist_container.py

@@ -357,6 +357,8 @@ def move_playlist(self, from_index, to_index, dry_run=False):
         If ``dry_run`` is :class:`True` the move isn't actually done. It is
         only checked if the move is possible.
         """
+        if from_index == to_index:
+            return
         spotify.Error.maybe_raise(lib.sp_playlistcontainer_move_playlist(
             self._sp_playlistcontainer, from_index, to_index, int(dry_run)))
 

tests/test_playlist_container.py

@@ -1024,6 +1024,18 @@ def test_move_playlist_out_of_range_fails(self, lib_mock):
         with self.assertRaises(spotify.Error):
             playlist_container.move_playlist(5, 7)
 
+    def test_move_playlist_to_itself_is_a_noop(self, lib_mock):
+        lib_mock.sp_playlistcontainer_move_playlist.return_value = int(
+            spotify.ErrorType.INVALID_INDATA)
+        sp_playlistcontainer = spotify.ffi.cast('sp_playlistcontainer *', 42)
+        playlist_container = spotify.PlaylistContainer(
+            self.session, sp_playlistcontainer=sp_playlistcontainer)
+
+        playlist_container.move_playlist(5, 5)
+
+        self.assertEqual(
+            lib_mock.sp_playlistcontainer_move_playlist.call_count, 0)
+
     @mock.patch('spotify.User', spec=spotify.User)
     def test_owner(self, user_mock, lib_mock):
         user_mock.return_value = mock.sentinel.user