From e861c5b61a380252866cbe577609444756224652 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 7 Mar 2018 11:14:17 +0530
Subject: [PATCH] Ignore failure to unpickle stored conversion options

---
 src/calibre/db/backend.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/calibre/db/backend.py b/src/calibre/db/backend.py
index df3205510e..37328758d2 100644
--- a/src/calibre/db/backend.py
+++ b/src/calibre/db/backend.py
@@ -1695,7 +1695,11 @@ class DB(object):
     def conversion_options(self, book_id, fmt):
         for (data,) in self.conn.get('SELECT data FROM conversion_options WHERE book=? AND format=?', (book_id, fmt.upper())):
             if data:
-                return safe_pickle.loads(bytes(data))
+                try:
+                    return safe_pickle.loads(bytes(data))
+                except Exception:
+                    import traceback
+                    traceback.print_exc()
 
     def has_conversion_options(self, ids, fmt='PIPE'):
         ids = frozenset(ids)