From 4b3cc1ed54043defac2c62ca3cb170962e036545 Mon Sep 17 00:00:00 2001
From: Charles Haley <github@charles.haleys.org>
Date: Thu, 14 Jul 2016 11:01:37 +0200
Subject: [PATCH] Bug #1602908: csv catalog not formatting is_multiple custom
 columns correctly

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

diff --git a/src/calibre/library/catalogs/csv_xml.py b/src/calibre/library/catalogs/csv_xml.py
index fa64512f05..174558685b 100644
--- a/src/calibre/library/catalogs/csv_xml.py
+++ b/src/calibre/library/catalogs/csv_xml.py
@@ -116,6 +116,8 @@ class CSV_XML(CatalogPlugin):
                 for field in fields:
                     if field.startswith('#'):
                         item = db.get_field(entry['id'], field, index_is_id=True)
+                        if isinstance(item, (list, tuple)):
+                            item = ', '.join(item)
                     elif field == 'library_name':
                         item = current_library
                     elif field == 'title_sort':