csv_import: ignore empty role values (#50158)

src/authentic2/csv_import.py

@@ -727,6 +727,8 @@ class UserCsvImporter(object):
         return success
 
     def add_role(self, cell, user, do_clear=False):
+        if not cell.value.strip():
+            return True
         try:
             if cell.header.name == ROLE_NAME:
                 role = Role.objects.get(name=cell.value, ou=self.ou)

tests/test_csv_import.py

@@ -495,6 +495,12 @@ tnoel@entrouvert.com,test_name'''
     assert importer.has_errors
     assert importer.errors[0].code == 'invalid-role-column'
 
+    # empty role name doesn't raise error
+    content_name_error = '\n'.join((base_header + '_role_name', base_user + ''))
+    importer = user_csv_importer_factory(content_name_error)
+    assert importer.run()
+    assert not importer.has_errors
+
 
 def test_csv_registration_options(profile, user_csv_importer_factory):
     content = '''email key,first_name,last_name,@registration