From be977db0d94ba1e4c3146fc65a4c939a62d98069 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 5 Mar 2013 09:51:36 +0530
Subject: [PATCH] Fix updating the calibre application id in EPUBs that also
 use the application id as the package id.

---
 src/calibre/ebooks/metadata/opf2.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 1950ee4621..b36d2363d3 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -941,9 +941,19 @@ class OPF(object): # {{{
                 return self.get_text(match) or None
 
         def fset(self, val):
+            removed_ids = set()
             for x in tuple(self.application_id_path(self.metadata)):
+                removed_ids.add(x.get('id', None))
                 x.getparent().remove(x)
+
+            uuid_id = None
+            for attr in self.root.attrib:
+                if attr.endswith('unique-identifier'):
+                    uuid_id = self.root.attrib[attr]
+                    break
             attrib = {'{%s}scheme'%self.NAMESPACES['opf']: 'calibre'}
+            if uuid_id and uuid_id in removed_ids:
+                attrib['id'] = uuid_id
             self.set_text(self.create_metadata_element(
                 'identifier', attrib=attrib), unicode(val))