Check doi in usual info fields

src/calibre/ebooks/metadata/pdf.py

@@ -9,7 +9,8 @@ from functools import partial
 from calibre import prints
 from calibre.constants import iswindows
 from calibre.ptempfile import TemporaryDirectory
-from calibre.ebooks.metadata import MetaInformation, string_to_authors, check_isbn
+from calibre.ebooks.metadata import MetaInformation, string_to_authors, \
+                                    check_isbn, check_doi
 from calibre.utils.ipc.simple_worker import fork_job, WorkerError
 
 #_isbn_pat = re.compile(r'ISBN[: ]*([-0-9Xx]+)')
@@ -134,6 +135,15 @@ def get_metadata(stream, cover=True):
     if 'xmp_metadata' in info:
         from calibre.ebooks.metadata.xmp import consolidate_metadata
         mi = consolidate_metadata(mi, info['xmp_metadata'])
+
+    if 'doi' not in mi.get_identifiers().iterkeys():
+        for k,v in info.iteritems():
+            if k != 'xmp_metadata':
+                doi = check_doi(v)
+                if doi:
+                    mi.set_identifiers({'doi':doi})
+                    break
+
     if cdata:
         mi.cover_data = ('jpeg', cdata)
     return mi

src/calibre/ebooks/metadata/xmp.py

@@ -13,7 +13,6 @@ from collections import defaultdict
 from lxml import etree
 from lxml.builder import ElementMaker
 
-from calibre import prints
 from calibre import replace_entities
 from calibre.ebooks.metadata import check_isbn, check_doi
 from calibre.ebooks.metadata.book.base import Metadata