From 1f11cf9521114447b3e32e2ac88f075ffaa37555 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Tue, 11 Jun 2019 01:15:24 -0700 Subject: [PATCH] bpo-37219: Remove erroneous optimization for differencing an empty set (GH-13965) --- Lib/test/test_set.py | 6 ++++++ .../2019-06-10-23-18-31.bpo-37219.jPSufq.rst | 1 + Objects/setobject.c | 8 -------- 3 files changed, 7 insertions(+), 8 deletions(-) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2019-06-10-23-18-31.bpo-37219.jPSufq.rst diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py index bb1081f034f..e4766ab190b 100644 --- a/Lib/test/test_set.py +++ b/Lib/test/test_set.py @@ -895,6 +895,12 @@ class TestBasicOps: self.assertEqual(self.set, copy, "%s != %s" % (self.set, copy)) + def test_issue_37219(self): + with self.assertRaises(TypeError): + set().difference(123) + with self.assertRaises(TypeError): + set().difference_update(123) + #------------------------------------------------------------------------------ class TestBasicOpsEmpty(TestBasicOps, unittest.TestCase): diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-06-10-23-18-31.bpo-37219.jPSufq.rst b/Misc/NEWS.d/next/Core and Builtins/2019-06-10-23-18-31.bpo-37219.jPSufq.rst new file mode 100644 index 00000000000..ef8f52dce67 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2019-06-10-23-18-31.bpo-37219.jPSufq.rst @@ -0,0 +1 @@ +Remove errorneous optimization for empty set differences. diff --git a/Objects/setobject.c b/Objects/setobject.c index bd031600c1b..8cd95ba890d 100644 --- a/Objects/setobject.c +++ b/Objects/setobject.c @@ -1456,10 +1456,6 @@ PyDoc_STRVAR(isdisjoint_doc, static int set_difference_update_internal(PySetObject *so, PyObject *other) { - if (PySet_GET_SIZE(so) == 0) { - return 0; - } - if ((PyObject *)so == other) return set_clear_internal(so); @@ -1534,10 +1530,6 @@ set_difference(PySetObject *so, PyObject *other) Py_ssize_t pos = 0, other_size; int rv; - if (PySet_GET_SIZE(so) == 0) { - return set_copy(so, NULL); - } - if (PyAnySet_Check(other)) { other_size = PySet_GET_SIZE(other); }