From b14e8904032da55f9408bc7846faa7c7c2edb8e8 Mon Sep 17 00:00:00 2001
From: Charles Haley <>
Date: Sat, 23 Apr 2011 13:02:20 +0100
Subject: [PATCH] Improve error handling when sorting date-subtype composite
 columns

---
 src/calibre/library/caches.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index 663b2b71ab..16661056e8 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -1005,9 +1005,9 @@ class SortKeyGenerator(object):
                 if sb == 'date':
                     try:
                         val = parse_date(val)
-                        dt = 'datetime'
                     except:
-                        pass
+                        val = UNDEFINED_DATE
+                    dt = 'datetime'
                 elif sb == 'number':
                     try:
                         val = float(val)