From dd3e52df27f03b14357e25bd35592250474afeb8 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 5 Sep 2014 10:41:00 +0530
Subject: [PATCH] Also clear languages when updating metadata in EPUB

---
 src/calibre/ebooks/metadata/opf2.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 10ac69ac73..6139dea6cf 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -1262,8 +1262,10 @@ class OPF(object):  # {{{
             else:
                 setattr(self, attr, val)
         langs = getattr(mi, 'languages', [])
-        if langs and langs != ['und']:
-            self.languages = langs
+        if langs == ['und']:
+            langs = []
+        if apply_null or langs:
+            self.languages = langs or []
         temp = self.to_book_metadata()
         temp.smart_update(mi, replace_metadata=replace_metadata)
         if not replace_metadata and callable(getattr(temp, 'custom_field_keys', None)):