...

src/calibre/ebooks/metadata/sources/covers.py

@@ -76,6 +76,11 @@ def run_download(log, results, abort,
         (plugin, width, height, fmt, bytes)
 
     '''
+    if title == _('Unknown'):
+        title = None
+    if authors == [_('Unknown')]:
+        authors = None
+
     plugins = [p for p in metadata_plugins(['cover']) if p.is_configured()]
 
     rq = Queue()

src/calibre/ebooks/metadata/sources/identify.py

@@ -253,6 +253,10 @@ def merge_identify_results(result_map, log):
 
 def identify(log, abort, # {{{
         title=None, authors=None, identifiers={}, timeout=30):
+    if title == _('Unknown'):
+        title = None
+    if authors == [_('Unknown')]:
+        authors = None
     start_time = time.time()
     plugins = [p for p in metadata_plugins(['identify']) if p.is_configured()]
 

src/calibre/ebooks/metadata/sources/isbndb.py

@@ -7,7 +7,13 @@ __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-from calibre.ebooks.metadata.sources.base import Source
+from urllib import quote
+
+from calibre.ebooks.metadata import check_isbn
+from calibre.ebooks.metadata.sources.base import Source, Option
+
+BASE_URL = 'http://isbndb.com/api/books.xml?access_key=%s&page_number=1&results=subjects,authors,texts&'
+
 
 class ISBNDB(Source):
 
@@ -18,6 +24,14 @@ class ISBNDB(Source):
     touched_fields = frozenset(['title', 'authors',
         'identifier:isbn', 'comments', 'publisher'])
     supports_gzip_transfer_encoding = True
+    # Shortcut, since we have no cached cover URLS
+    cached_cover_url_is_reliable = False
+
+    options = (
+            Option('isbndb_key', 'string', None, _('IsbnDB key:'),
+                _('To use isbndb.com you have to sign up for a free account'
+                    'at isbndb.com and get an access key.')),
+            )
 
     def __init__(self, *args, **kwargs):
         Source.__init__(self, *args, **kwargs)
@@ -35,9 +49,33 @@ class ISBNDB(Source):
             except:
                 pass
 
-        self.isbndb_key = prefs['isbndb_key']
+    @property
+    def isbndb_key(self):
+        return self.prefs['isbndb_key']
 
     def is_configured(self):
         return self.isbndb_key is not None
 
+    def create_query(self, log, title=None, authors=None, identifiers={}): # {{{
+        base_url = BASE_URL%self.isbndb_key
+        isbn = check_isbn(identifiers.get('isbn', None))
+        q = ''
+        if isbn is not None:
+            q = 'index1=isbn&value1='+isbn
+        elif title or authors:
+            tokens = []
+            title_tokens = list(self.get_title_tokens(title))
+            tokens += title_tokens
+            author_tokens = self.get_author_tokens(authors,
+                    only_first_author=True)
+            tokens += author_tokens
+            tokens = [quote(t) for t in tokens]
+            q = '+'.join(tokens)
+            q = 'index1=combined&value1='+q
+
+        if not q:
+            return None
+        if isinstance(q, unicode):
+            q = q.encode('utf-8')
+        return base_url + q