Compatibility with pdftohtml/poppler 0.18+

In poppler 0.18+, pdftohtml generates " " instead of " ", so
make sure both are accepted.

product/ERP5OOo/tests/testDms.py

@@ -71,6 +71,7 @@ from threading import Thread
 import httplib
 import urllib
 import difflib
+import re
 from AccessControl import Unauthorized
 from Products.ERP5Type import Permissions
 from Products.ERP5Type.tests.backportUnittest import expectedFailure
@@ -1238,14 +1239,18 @@ class TestDocument(TestDocumentMixin):
     # XXX: search limited to a certain date range
     # XXX: search mode
 
+  #   and   are equivalent, and "pdftohtml" can generate
+  # either depending on the version of the "poppler" package used.
+  re_html_nbsp = re.compile('&(nbsp|#160);')
+
   def test_PDFTextContent(self):
     upload_file = makeFileUpload('REF-en-001.pdf')
     document = self.portal.portal_contributions.newContent(file=upload_file)
     self.assertEquals('PDF', document.getPortalType())
     self.assertEquals('I use reference to look up TEST\n',
                       document._convertToText())
-    self.assert_('I use reference to look up TEST' in
-                 document._convertToHTML().replace(' ', ' '))
+    html_data = re.sub(self.re_html_nbsp, ' ', document._convertToHTML())
+    self.assert_('I use reference to look up TEST' in html_data)
     self.assert_('I use reference to look up TEST' in
                  document.SearchableText())