From 02dd1e9443944a2145ad386b6f4f60c4fbc42ca9 Mon Sep 17 00:00:00 2001
From: Mouse Reeve <mousereeve@riseup.net>
Date: Mon, 17 Jan 2022 12:45:32 -0800
Subject: [PATCH] Use False instead of None for test values

---
 bookwyrm/models/status.py              | 3 ++-
 bookwyrm/templatetags/bookwyrm_tags.py | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/bookwyrm/models/status.py b/bookwyrm/models/status.py
index 1368e05e..29b3ba9c 100644
--- a/bookwyrm/models/status.py
+++ b/bookwyrm/models/status.py
@@ -376,7 +376,8 @@ class Review(BookStatus):
 
     def save(self, *args, **kwargs):
         """clear rating caches"""
-        cache.delete(f"book-rating-{self.book.parent_work.id}-*")
+        if self.book.parent_work:
+            cache.delete(f"book-rating-{self.book.parent_work.id}-*")
         super().save(*args, **kwargs)
 
 
diff --git a/bookwyrm/templatetags/bookwyrm_tags.py b/bookwyrm/templatetags/bookwyrm_tags.py
index 6e4e8d84..9b4c507f 100644
--- a/bookwyrm/templatetags/bookwyrm_tags.py
+++ b/bookwyrm/templatetags/bookwyrm_tags.py
@@ -17,7 +17,7 @@ def get_rating(book, user):
         f"book-rating-{book.parent_work.id}-{user.id}",
         lambda u, b: models.Review.privacy_filter(u)
         .filter(book__parent_work__editions=b)
-        .aggregate(Avg("rating"))["rating__avg"],
+        .aggregate(Avg("rating"))["rating__avg"] or 0,
         user,
         book,
         timeout=15552000,
@@ -144,7 +144,7 @@ def active_shelf(context, book):
                 models.ShelfBook.objects.filter(
                     shelf__user=u,
                     book__parent_work__editions=b,
-                ).first()
+                ).first() or False
             ),
             user,
             book,
@@ -162,7 +162,7 @@ def latest_read_through(book, user):
         lambda u, b: (
             models.ReadThrough.objects.filter(user=u, book=b, is_active=True)
             .order_by("-start_date")
-            .first()
+            .first() or False
         ),
         user,
         book,