From dab89f6f791a0ecb10b47dbb3b82ddf0d53235c8 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 4 Jan 2011 08:53:57 -0700
Subject: [PATCH] Fix bug when using tags like custom column in the template
 language

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

diff --git a/src/calibre/library/save_to_disk.py b/src/calibre/library/save_to_disk.py
index 3179551b45..20c0a7e59c 100644
--- a/src/calibre/library/save_to_disk.py
+++ b/src/calibre/library/save_to_disk.py
@@ -131,6 +131,8 @@ class SafeFormat(TemplateFormatter):
                 return self.composite_values[key]
             if key in kwargs:
                 val = kwargs[key]
+                if isinstance(val, list):
+                    val = ','.join(val)
                 return val.replace('/', '_').replace('\\', '_')
             return ''
         except: