From 9e9ee50421c857b443e2060274f17fb884d54473 Mon Sep 17 00:00:00 2001
From: blhsing <blhsing@gmail.com>
Date: Tue, 11 Jun 2024 13:42:49 +0800
Subject: [PATCH] gh-65454: avoid triggering call to a PropertyMock in
 NonCallableMock.__setattr__ (#120019)

---
 Lib/test/test_unittest/testmock/testhelpers.py            | 8 ++++++++
 Lib/unittest/mock.py                                      | 3 +++
 .../Library/2024-06-04-08-57-02.gh-issue-65454.o9j4wF.rst | 1 +
 3 files changed, 12 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-06-04-08-57-02.gh-issue-65454.o9j4wF.rst

diff --git a/Lib/test/test_unittest/testmock/testhelpers.py b/Lib/test/test_unittest/testmock/testhelpers.py
index 74785a83757..c9c20f008ca 100644
--- a/Lib/test/test_unittest/testmock/testhelpers.py
+++ b/Lib/test/test_unittest/testmock/testhelpers.py
@@ -1127,6 +1127,14 @@ class TestCallList(unittest.TestCase):
         p.assert_called_once_with()
 
 
+    def test_propertymock_attach(self):
+        m = Mock()
+        p = PropertyMock()
+        type(m).foo = p
+        m.attach_mock(p, 'foo')
+        self.assertEqual(m.mock_calls, [])
+
+
 class TestCallablePredicate(unittest.TestCase):
 
     def test_type(self):
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index edabb4520c1..08975e0e1bd 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -830,6 +830,9 @@ class NonCallableMock(Base):
             mock_name = f'{self._extract_mock_name()}.{name}'
             raise AttributeError(f'Cannot set {mock_name}')
 
+        if isinstance(value, PropertyMock):
+            self.__dict__[name] = value
+            return
         return object.__setattr__(self, name, value)
 
 
diff --git a/Misc/NEWS.d/next/Library/2024-06-04-08-57-02.gh-issue-65454.o9j4wF.rst b/Misc/NEWS.d/next/Library/2024-06-04-08-57-02.gh-issue-65454.o9j4wF.rst
new file mode 100644
index 00000000000..0b232cf8ca1
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-06-04-08-57-02.gh-issue-65454.o9j4wF.rst
@@ -0,0 +1 @@
+:func:`unittest.mock.Mock.attach_mock` no longer triggers a call to a ``PropertyMock`` being attached.