From ee808594ca3df4dbbe0eb134da37eec6ad424a38 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 2 Apr 2012 16:25:58 +0530
Subject: [PATCH] EPUB metadata: Strip pointless urn:isbn: prefix from ISBN
 declaration when reading metadata

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

diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index c30545e6e1..d21727f3c3 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -883,6 +883,8 @@ class OPF(object): # {{{
                     val = etree.tostring(x, with_tail=False, encoding=unicode,
                             method='text').strip()
                     if val and typ not in ('calibre', 'uuid'):
+                        if typ == 'isbn' and val.lower().startswith('urn:isbn:'):
+                            val = val[len('urn:isbn:'):]
                         identifiers[typ] = val
                     found_scheme = True
                     break