Allow calibredb list to output only book ids

Merge branch 'master' of https://github.com/cbhaley/calibre

src/calibre/library/caches.py

@@ -921,7 +921,7 @@ class ResultCache(SearchQueryParser):  # {{{
     def remove(self, id):
         try:
             self._uuid_map.pop(self._data[id][self._uuid_column_index], None)
-        except IndexError:
+        except (IndexError, TypeError):
             pass  # id is out of bounds -- no uuid in the map to remove
         try:
             self._data[id] = None

src/calibre/library/cli.py

@@ -199,6 +199,7 @@ def command_list(args, dbpath):
             afields.add('*'+f)
             if data['datatype'] == 'series':
                 afields.add('*'+f+'_index')
+    if opts.fields.strip():
         fields = [str(f.strip().lower()) for f in opts.fields.split(',')]
         if 'all' in fields:
             fields = sorted(list(afields))
@@ -208,6 +209,8 @@ def command_list(args, dbpath):
             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()