Don't call lookup on backends with uris they don't support

mopidy/frontends/mpd/protocol/current_playlist.py

@@ -11,11 +11,15 @@ def add(frontend, uri):
         Adds the file ``URI`` to the playlist (directories add recursively).
         ``URI`` can also be a single file.
     """
-    track = frontend.backend.library.lookup(uri)
-    if track is None:
-        raise MpdNoExistError(
-            u'directory or file not found', command=u'add')
-    frontend.backend.current_playlist.add(track)
+    for handler_prefix in frontend.backend.uri_handlers:
+        if uri.startswith(handler_prefix):
+            track = frontend.backend.library.lookup(uri)
+            if track is not None:
+                frontend.backend.current_playlist.add(track)
+                return
+
+    raise MpdNoExistError(
+        u'directory or file not found', command=u'add')
 
 @handle_pattern(r'^addid "(?P<uri>[^"]*)"( "(?P<songpos>\d+)")*$')
 def addid(frontend, uri, songpos=None):

tests/frontends/mpd/current_playlist_test.py

@@ -22,6 +22,12 @@ class CurrentPlaylistHandlerTest(unittest.TestCase):
         self.assertEqual(len(result), 1)
         self.assert_(u'OK' in result)
 
+    def test_add_with_uri_not_found_in_library_should_not_call_lookup(self):
+        self.b.library.lookup = lambda uri: self.fail("Shouldn't run")
+        result = self.h.handle_request(u'add "foo"')
+        self.assertEqual(result[0],
+            u'ACK [50@0] {add} directory or file not found')
+
     def test_add_with_uri_not_found_in_library_should_ack(self):
         result = self.h.handle_request(u'add "dummy://foo"')
         self.assertEqual(result[0],