mpd: Compile protocol matching regexpes

This caused a single test failure, which was fixed.

mopidy/frontends/mpd/protocol/__init__.py

@@ -56,10 +56,11 @@ def handle_request(pattern, auth_required=True):
         if match is not None:
             mpd_commands.add(
                 MpdCommand(name=match.group(), auth_required=auth_required))
-        if pattern in request_handlers:
+        compiled_pattern = re.compile(pattern)
+        if compiled_pattern in request_handlers:
             raise ValueError('Tried to redefine handler for %s with %s' % (
                 pattern, func))
-        request_handlers[pattern] = func
+        request_handlers[compiled_pattern] = func
         func.__doc__ = '    - *Pattern:* ``%s``\n\n%s' % (
             pattern, func.__doc__ or '')
         return func

mopidy/frontends/mpd/protocol/current_playlist.py

@@ -232,7 +232,6 @@ def playlistid(context, tlid=None):
 
 
 @handle_request(r'^playlistinfo$')
-@handle_request(r'^playlistinfo "-1"$')
 @handle_request(r'^playlistinfo "(?P<songpos>-?\d+)"$')
 @handle_request(r'^playlistinfo "(?P<start>\d+):(?P<end>\d+)*"$')
 def playlistinfo(context, songpos=None, start=None, end=None):
@@ -250,6 +249,8 @@ def playlistinfo(context, songpos=None, start=None, end=None):
     - uses negative indexes, like ``playlistinfo "-1"``, to request
       the entire playlist
     """
+    if songpos == '-1':
+        songpos = None
     if songpos is not None:
         songpos = int(songpos)
         tl_track = context.core.tracklist.tl_tracks.get()[songpos]