[profile gen] Avoid duplicated format ids / mime types in enum

There may be cases where several concepts use the same label, mostly in the case
of format identifier but do the same thing for mime types as a safety belt.

cubicweb_seda/entities/profile_generation.py

@@ -891,14 +891,14 @@ class SEDA1XSDExport(SEDA2ExportAdapter):
 
         format_id = data_object.format_id
         if format_id is not None:
-            format_ids = [_concept_value(concept, self.concepts_language)
-                          for concept in format_id.concepts]
+            format_ids = sorted(set(_concept_value(concept, self.concepts_language)
+                                    for concept in format_id.concepts))
         else:
             format_ids = []
         mime_type = data_object.mime_type
         if mime_type is not None:
-            mime_types = [_concept_value(concept, self.concepts_language)
-                          for concept in mime_type.concepts]
+            mime_types = sorted(set(_concept_value(concept, self.concepts_language)
+                                    for concept in mime_type.concepts))
         else:
             mime_types = []
         encoding = data_object.encoding

test/test_profile_generation.py

@@ -1018,6 +1018,24 @@ class OldSEDAExportTC(RelaxNGTestMixin, CubicWebTC):
             self.assertEqual([node.attrib['name'] for node in root],
                              ['ArchiveObject', 'Document'])
 
+    def test_duplicated_format_id(self):
+        with self.admin_access.cnx() as cnx:
+            scheme = testutils.scheme_for_type(cnx, 'file_category', None,
+                                               u'fmt/123', u'fmt/123')
+            concepts = scheme.reverse_in_scheme
+
+            transfer = cnx.create_entity('SEDAArchiveTransfer', title=u'my profile',
+                                         simplified_profile=True)
+            bdo = testutils.create_data_object(transfer)
+            bdo.format_id.cw_set(seda_format_id_to=concepts)
+
+            adapter = transfer.cw_adapt_to('SEDA-1.0.rng')
+            root = etree.Element('test-root')
+            adapter.xsd_attachment(root, bdo)
+
+            self.assertEqual([node.text for node in self.xpath(root, '//rng:value')],
+                             ['fmt/123'])
+
 
 class SEDAExportUnitTest(unittest.TestCase):