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 1/2] 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:

From d47603bdacfe7fc92b552de59e763b52ef800cb8 Mon Sep 17 00:00:00 2001
From: Charles Haley <cbhaley@i.wont.say.com>
Date: Sat, 27 Jul 2013 10:33:14 +0200
Subject: [PATCH 2/2] Allow an empty field specifier in calibredb, permitting
 one to get a list of ids

---
 src/calibre/library/cli.py | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/calibre/library/cli.py b/src/calibre/library/cli.py
index 012d88dace..a6ecca3721 100644
--- a/src/calibre/library/cli.py
+++ b/src/calibre/library/cli.py
@@ -199,15 +199,18 @@ def command_list(args, dbpath):
             afields.add('*'+f)
             if data['datatype'] == 'series':
                 afields.add('*'+f+'_index')
-    fields = [str(f.strip().lower()) for f in opts.fields.split(',')]
-    if 'all' in fields:
-        fields = sorted(list(afields))
-    if not set(fields).issubset(afields):
-        parser.print_help()
-        print
-        prints(_('Invalid fields. Available fields:'),
-                ','.join(sorted(afields)), file=sys.stderr)
-        return 1
+    if opts.fields.strip():
+        fields = [str(f.strip().lower()) for f in opts.fields.split(',')]
+        if 'all' in fields:
+            fields = sorted(list(afields))
+        if not set(fields).issubset(afields):
+            parser.print_help()
+            print
+            prints(_('Invalid fields. Available fields:'),
+                    ','.join(sorted(afields)), file=sys.stderr)
+            return 1
+    else:
+        fields = []
 
     if not opts.sort_by in afields and opts.sort_by is not None:
         parser.print_help()