From e79ef640becb4b59dba11c1dfcce0ea87000919b Mon Sep 17 00:00:00 2001
From: Jan Szejko <janek37@gmail.com>
Date: Tue, 5 Jun 2018 17:26:04 +0200
Subject: [PATCH] fix to pass tests

---
 src/catalogue/models/book.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/catalogue/models/book.py b/src/catalogue/models/book.py
index 004c27e89..7cd6386ba 100644
--- a/src/catalogue/models/book.py
+++ b/src/catalogue/models/book.py
@@ -233,7 +233,7 @@ class Book(models.Model):
     def get_audio_length(self):
         from mutagen.mp3 import MP3
         total = 0
-        for media in self.get_mp3():
+        for media in self.get_mp3() or ():
             audio = MP3(media.file.path)
             total += audio.info.length
         return int(total)
-- 
2.20.1