Fix last.fm bug for users not listening to something.

The last.fm plugin previously worked only for users not listening to
anything, and then it was 'fixed' for users listening to something, but
broke for users not listening to something. See lastfm.py comments for
changes.

plugins/lastfm.py

@@ -20,12 +20,29 @@ def lastfm(inp, nick='', say=None):
         else:
             return "your nick is not a LastFM account. try '.lastfm username'."
 
-    track = response["recenttracks"]["track"]
+    tracks = response["recenttracks"]["track"]
+
+    if len(tracks) == 0:
+        return "no recent tracks for user %r found" % user
+
+    if type(tracks) == list:
+        # if the user is listening to something, the tracks entry is a list
+        # the first item is the current track
+        track = tracks[0]
+        status = 'current track'
+    elif type(tracks) == dict:
+        # otherwise, they aren't listening to anything right now, and
+        # the tracks entry is a dict representing the most recent track
+        track = tracks
+        status = 'last track'
+    else:
+        return "error parsing track listing"
+
     title = track["name"]
     album = track["album"]["#text"]
     artist = track["artist"]["#text"]
 
-    ret = "\x02%s\x0F's last track - \x02%s\x0f" % (user, title)
+    ret = "\x02%s\x0F's %s - \x02%s\x0f" % (user, status, title)
     if artist:
         ret += " by \x02%s\x0f" % artist
     if album: