views/episode_detail: defaults to program page when unauthorized user calls unpublished episode

aircox/views/episode.py

@@ -40,6 +40,13 @@ class EpisodeDetailView(PageDetailView):
     def get_related_url(self):
         return reverse("episode-list", kwargs={"parent_slug": self.object.parent.slug})
 
+    def get_queryset(self):
+        episode = get_object_or_404(Episode, slug=self.kwargs["slug"])
+        qs = super().get_queryset()
+        if not qs:
+            return HttpResponseRedirect(reverse("program-detail", kwargs={"slug": episode.program.slug}))
+        return qs
+
 
 @attach
 class EpisodeListView(PageListView):