From cef604bda215820823da4e6b20bf609a291b49f4 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 8 Nov 2011 13:32:12 +0530
Subject: [PATCH] Treat author_sort = _('Unknown') as null

---
 src/calibre/ebooks/metadata/book/base.py | 1 +
 src/calibre/library/save_to_disk.py      | 2 --
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/calibre/ebooks/metadata/book/base.py b/src/calibre/ebooks/metadata/book/base.py
index 58f28af01f..53d336a23d 100644
--- a/src/calibre/ebooks/metadata/book/base.py
+++ b/src/calibre/ebooks/metadata/book/base.py
@@ -32,6 +32,7 @@ NULL_VALUES = {
                 'device_collections': [],
                 'author_sort_map': {},
                 'authors'      : [_('Unknown')],
+                'author_sort'  : _('Unknown'),
                 'title'        : _('Unknown'),
                 'user_categories' : {},
                 'author_link_map' : {},
diff --git a/src/calibre/library/save_to_disk.py b/src/calibre/library/save_to_disk.py
index c8ac28a01f..69565e07d7 100644
--- a/src/calibre/library/save_to_disk.py
+++ b/src/calibre/library/save_to_disk.py
@@ -173,8 +173,6 @@ def get_components(template, mi, id, timefmt='%b %Y', length=250,
     tsorder = tweaks['save_template_title_series_sorting']
     format_args = FORMAT_ARGS.copy()
     format_args.update(mi.all_non_none_fields())
-    if mi.author_sort == _('Unknown'):
-        format_args['author_sort'] = _('Unknown')
     if mi.title:
         if tsorder == 'strictly_alphabetic':
             v = mi.title