From 05cf311555df62c4a2191617e0bc6e0e42e5373d Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 29 Sep 2010 18:48:17 -0600
Subject: [PATCH] Cleanup ISBNdb metadata plugin

---
 src/calibre/ebooks/metadata/isbndb.py | 38 ++++++++++++++++++---------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/calibre/ebooks/metadata/isbndb.py b/src/calibre/ebooks/metadata/isbndb.py
index 6c321bf9d3..6416dcdc39 100644
--- a/src/calibre/ebooks/metadata/isbndb.py
+++ b/src/calibre/ebooks/metadata/isbndb.py
@@ -47,29 +47,43 @@ class ISBNDBMetadata(Metadata):
     def __init__(self, book):
         Metadata.__init__(self, None, [])
 
+        def tostring(e):
+            if not hasattr(e, 'string'):
+                return None
+            ans = e.string
+            if ans is not None:
+                ans = unicode(ans).strip()
+            if not ans:
+                ans = None
+            return ans
+
         self.isbn = unicode(book.get('isbn13', book.get('isbn')))
-        self.title = unicode(book.find('titlelong').string)
+        self.title = tostring(book.find('titlelong'))
         if not self.title:
-            self.title = unicode(book.find('title').string)
+            self.title = tostring(book.find('title'))
+        if not self.title:
+            self.title = _('Unknown')
         self.title = unicode(self.title).strip()
-        au = unicode(book.find('authorstext').string).strip()
-        temp = au.split(',')
         self.authors = []
-        for au in temp:
-            if not au: continue
-            self.authors.extend([a.strip() for a in au.split('&amp;')])
+        au = tostring(book.find('authorstext'))
+        if au:
+            au = au.strip()
+            temp = au.split(',')
+            for au in temp:
+                if not au: continue
+                self.authors.extend([a.strip() for a in au.split('&amp;')])
 
         try:
-            self.author_sort = book.find('authors').find('person').string
+            self.author_sort = tostring(book.find('authors').find('person'))
             if self.authors and self.author_sort == self.authors[0]:
                 self.author_sort = None
         except:
             pass
-        self.publisher = unicode(book.find('publishertext').string)
+        self.publisher = tostring(book.find('publishertext'))
 
-        summ = book.find('summary')
-        if summ and hasattr(summ, 'string') and summ.string:
-            self.comments = 'SUMMARY:\n'+unicode(summ.string)
+        summ = tostring(book.find('summary'))
+        if summ:
+            self.comments = 'SUMMARY:\n'+summ.string
 
 
 def build_isbn(base_url, opts):