Modify get_cover to allow it to download episode art

Author: E.S. Rosenberg a.k.a. Keeper of the Keys

src/gpodder/coverart.py

@@ -44,9 +44,20 @@ class CoverDownloader(object):
     def __init__(self, core):
         self.core = core
 
-    def get_cover(self, podcast, download=False):
-        filename = podcast.cover_file
-        cover_url = podcast.cover_url
+    def get_cover(self, podcast, download=False, episode = None):
+        if episode != None:
+            # Get episode art.
+            filename = episode.art_file
+            cover_url = episode.episode_art_url
+            if cover_url is None:
+                return None
+        else:
+            # Get podcast cover.
+            filename = podcast.cover_file
+            cover_url = podcast.cover_url
+
+        username = podcast.auth_username
+        password = podcast.auth_password
 
         # Return already existing files
         for extension in self.EXTENSIONS:
@@ -62,8 +73,7 @@ def get_cover(self, podcast, download=False):
 
             # We have to add username/password, because password-protected
             # feeds might keep their cover art also protected (bug 1521)
-            cover_url = util.url_add_authentication(cover_url, podcast.auth_username,
-                                                    podcast.auth_password)
+            cover_url = util.url_add_authentication(cover_url, username, password)
 
             try:
                 logger.info('Downloading cover art: %s', cover_url)