From 06e4b9e49b92438e9b3882b444b76c2eb434f6cd Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 3 Apr 2010 12:04:43 +0530
Subject: [PATCH] ...

---
 src/calibre/ebooks/oeb/base.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index a77554062e..69b2d67b7a 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -1181,12 +1181,6 @@ class Manifest(object):
         :param:`href` are `None` then the corresponding item in the return
         tuple will also be `None`.
         """
-        def href_present(href):
-            for x in self.hrefs:
-                if x.lower() == href.lower():
-                    return True
-            return False
-
         if id is not None:
             base = id
             index = 1
@@ -1197,7 +1191,8 @@ class Manifest(object):
             href = urlnormalize(href)
             base, ext = os.path.splitext(href)
             index = 1
-            while href_present(href):
+            lhrefs = set([x.lower() for x in self.hrefs])
+            while href.lower() in lhrefs:
                 href = base + str(index) + ext
                 index += 1
         return id, href