From 748eb921c5294e5f3a2558f968d7684fed0e1d5c Mon Sep 17 00:00:00 2001
From: Charles Haley <cbhaley@i.wont.say.com>
Date: Sat, 27 Jul 2013 10:32:49 +0200
Subject: [PATCH] Prevent exception when deleting a non-existent book.

---
 src/calibre/library/caches.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index e552ead591..022ba9402e 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -920,7 +920,8 @@ class ResultCache(SearchQueryParser):  # {{{
 
     def remove(self, id):
         try:
-            self._uuid_map.pop(self._data[id][self._uuid_column_index], None)
+            if self._data[id] is not None:
+                self._uuid_map.pop(self._data[id][self._uuid_column_index], None)
         except IndexError:
             pass  # id is out of bounds -- no uuid in the map to remove
         try: