TST: Add test for setting item using python list (pandas-dev#19406)

Author: Margret `Pax` Williams

pandas/tests/series/indexing/test_setitem.py

@@ -126,6 +126,14 @@ def test_setitem_boolean_different_order(self, string_series):
 
         tm.assert_series_equal(copy, expected)
 
+    def test_setitem_boolean_using_python_list(self):
+        # GH#19406
+        series = Series([None, "b", None])
+        mask = series.isnull()
+        series[mask] = ["a", "c"]
+        expected = Series(["a", "b", "c"])
+        tm.assert_series_equal(series, expected)
+
     @pytest.mark.parametrize("value", [None, NaT, np.nan])
     def test_setitem_boolean_td64_values_cast_na(self, value):
         # GH#18586