Treat only really new episodes as new after an update

Make PodcastChannel.update() return a list of new episodes. Add a new
config variable ui.gtk.only_added_are_new. If this variable is True,
download, queue or show (depending on the value of config var
auto_download) only these new episodes, instead of all episodes marked
as new, after an update.

src/gpodder/config.py

@@ -154,6 +154,7 @@ defaults = {
 
             'toolbar': False,
             'new_episodes': 'show',  # ignore, show, queue, download
+            'only_added_are_new': False,  # Only just added episodes are considered new after an update
             'live_search_delay': 200,
             'search_always_visible': False,
             'find_as_you_type': True,

src/gpodder/gtkui/main.py

@@ -2842,6 +2842,7 @@ class gPodder(BuilderWidget, dbus.service.Object):
         def update_feed_cache_proc():
             updated_channels = []
             nr_update_errors = 0
+            new_episodes = []
             for updated, channel in enumerate(channels):
                 if self.feed_cache_update_cancelled:
                     break
@@ -2855,7 +2856,7 @@ class gPodder(BuilderWidget, dbus.service.Object):
                 try:
                     channel._update_error = None
                     util.idle_add(indicate_updating_podcast, channel)
-                    channel.update(max_episodes=self.config.limit.episodes)
+                    new_episodes.extend(channel.update(max_episodes=self.config.limit.episodes))
                     self._update_cover(channel)
                 except Exception as e:
                     message = str(e)
@@ -2899,7 +2900,7 @@ class gPodder(BuilderWidget, dbus.service.Object):
                        nr_update_errors) % {'count': nr_update_errors},
                     _('Error while updating feeds'), widget=self.treeChannels)
 
-            def update_feed_cache_finish_callback():
+            def update_feed_cache_finish_callback(new_episodes):
                 # Process received episode actions for all updated URLs
                 self.process_received_episode_actions()
 
@@ -2912,9 +2913,11 @@ class gPodder(BuilderWidget, dbus.service.Object):
                     # The user decided to abort the feed update
                     self.show_update_feeds_buttons()
 
-                # Only search for new episodes in podcasts that have been
-                # updated, not in other podcasts (for single-feed updates)
-                episodes = self.get_new_episodes([c for c in updated_channels])
+                # The filter extension can mark newly added episodes as old,
+                # so take only episodes marked as new.
+                episodes = ((e for e in new_episodes if e.check_is_new())
+                            if self.config.ui.gtk.only_added_are_new
+                            else self.get_new_episodes([c for c in updated_channels]))
 
                 if self.config.downloads.chronological_order:
                     # download older episodes first
@@ -2965,7 +2968,7 @@ class gPodder(BuilderWidget, dbus.service.Object):
 
                     self.show_update_feeds_buttons()
 
-            util.idle_add(update_feed_cache_finish_callback)
+            util.idle_add(update_feed_cache_finish_callback, new_episodes)
 
     def on_gPodder_delete_event(self, *args):
         """Called when the GUI wants to close the window

src/gpodder/model.py

@@ -1222,7 +1222,7 @@ class PodcastChannel(PodcastModelObject):
                 next_feed = None
 
         # mark episodes not new
-        real_new_episode_count = 0
+        real_new_episodes = []
         # Search all entries for new episodes
         for episode in new_episodes:
             # Workaround for bug 340: If the episode has been
@@ -1234,17 +1234,18 @@ class PodcastChannel(PodcastModelObject):
                 episode.save()
 
             if episode.is_new:
-                real_new_episode_count += 1
+                real_new_episodes.append(episode)
 
             # Only allow a certain number of new episodes per update
             if (self.download_strategy == PodcastChannel.STRATEGY_LATEST
-                    and real_new_episode_count > 1):
+                    and len(real_new_episodes) > 1):
                 episode.is_new = False
                 episode.save()
 
         self.children.extend(new_episodes)
 
         self.remove_unreachable_episodes(existing, seen_guids, max_episodes)
+        return real_new_episodes
 
     def remove_unreachable_episodes(self, existing, seen_guids, max_episodes):
         # Remove "unreachable" episodes - episodes that have not been
@@ -1276,11 +1277,12 @@ class PodcastChannel(PodcastModelObject):
 
     def update(self, max_episodes=0):
         max_episodes = int(max_episodes)
+        new_episodes = []
         try:
             result = self.feed_fetcher.fetch_channel(self, max_episodes)
 
             if result.status == feedcore.UPDATED_FEED:
-                self._consume_updated_feed(result.feed, max_episodes)
+                new_episodes = self._consume_updated_feed(result.feed, max_episodes)
             elif result.status == feedcore.NEW_LOCATION:
                 # FIXME: could return the feed because in autodiscovery it is parsed already
                 url = result.feed
@@ -1290,7 +1292,7 @@ class PodcastChannel(PodcastModelObject):
                 self.url = url
                 # With the updated URL, fetch the feed again
                 self.update(max_episodes)
-                return
+                return new_episodes
             elif result.status == feedcore.NOT_MODIFIED:
                 pass
 
@@ -1317,6 +1319,7 @@ class PodcastChannel(PodcastModelObject):
         self._determine_common_prefix()
 
         self.db.commit()
+        return new_episodes
 
     def delete(self):
         self.db.delete_podcast(self)