Ignore duplicate RequestedAttribute entries when filtering attributes

Signed-off-by: Ivan Kanakarakis <[email protected]>

Author: c00kiemon5ter

src/saml2/assertion.py

@@ -115,7 +115,9 @@ def _apply_attr_value_restrictions(attr, res, must=False):
         try:
             res[_fn].extend(_filter_values(ava[_fn], values))
         except KeyError:
-            res[_fn] = _filter_values(ava[_fn], values)
+            # ignore duplicate RequestedAttribute entries
+            val = _filter_values(ava[_fn], values)
+            res[_fn] = val if val is not None else []
 
         return _filter_values(ava[_fn], values, must)