From 8ef2b18e51cc38ad3f4d61befb6987939d3b2ac0 Mon Sep 17 00:00:00 2001
From: Charles Haley <>
Date: Mon, 10 Jan 2011 13:23:07 +0000
Subject: [PATCH] Fix for #8266: exception when book has no author.

---
 src/calibre/library/sqlite.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/calibre/library/sqlite.py b/src/calibre/library/sqlite.py
index 75856dd0f6..bd5a1f8ab9 100644
--- a/src/calibre/library/sqlite.py
+++ b/src/calibre/library/sqlite.py
@@ -99,7 +99,7 @@ class AumSortedConcatenate(object):
     def finalize(self):
         keys = self.ans.keys()
         if len(keys) == 0:
-            return None
+            return 'Unknown:::Unknown'
         if len(keys) == 1:
             return self.ans[keys[0]]
         return ':#:'.join([self.ans[v] for v in sorted(keys)])