Fix handling of bindvars when no parameters are provided

airflow/providers/oracle/hooks/oracle.py

@@ -309,6 +309,9 @@ def callproc(
         sql = f"BEGIN {identifier}({args}); END;"
 
         def handler(cursor):
+            if cursor.bindvars is None:
+                return
+
             if isinstance(cursor.bindvars, list):
                 return [v.getvalue() for v in cursor.bindvars]
 

tests/providers/oracle/hooks/test_oracle.py

@@ -292,6 +292,18 @@ def test_bulk_insert_rows_no_rows(self):
         with pytest.raises(ValueError):
             self.db_hook.bulk_insert_rows('table', rows)
 
+    def test_callproc_none(self):
+        parameters = None
+
+        class bindvar(int):
+            def getvalue(self):
+                return self
+
+        self.cur.bindvars = None
+        result = self.db_hook.callproc('proc', True, parameters)
+        assert self.cur.execute.mock_calls == [mock.call('BEGIN proc(); END;')]
+        assert result == parameters
+
     def test_callproc_dict(self):
         parameters = {"a": 1, "b": 2, "c": 3}