From d940c98f992e6f77737a68ea013e8121fe309fa5 Mon Sep 17 00:00:00 2001
From: Robert Collins <robert.collins@cognite.com>
Date: Mon, 27 May 2024 14:03:19 +0200
Subject: [PATCH 1/3] Issue #119600: mock: do not access attributes of original
 when new_callable is set

In order to patch flask.g e.g. as in #84982, that
proxies getattr must not be invoked. For that,
mock must not try to read from the original
object. In some cases that is unavoidable, e.g.
when doing autospec. However, patch("flask.g",
new_callable=MagicMock) should be entirely safe.
---
 Lib/unittest/mock.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 3ef83e263f53b74..edabb4520c13cdb 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1508,13 +1508,12 @@ def __enter__(self):
                 if isinstance(original, type):
                     # If we're patching out a class and there is a spec
                     inherit = True
-            if spec is None and _is_async_obj(original):
-                Klass = AsyncMock
-            else:
-                Klass = MagicMock
-            _kwargs = {}
+
+            # Determine the Klass to use
             if new_callable is not None:
                 Klass = new_callable
+            elif spec is None and _is_async_obj(original):
+                Klass = AsyncMock
             elif spec is not None or spec_set is not None:
                 this_spec = spec
                 if spec_set is not None:
@@ -1527,7 +1526,12 @@ def __enter__(self):
                     Klass = AsyncMock
                 elif not_callable:
                     Klass = NonCallableMagicMock
+                else:
+                    Klass = MagicMock
+            else:
+                Klass = MagicMock
 
+            _kwargs = {}
             if spec is not None:
                 _kwargs['spec'] = spec
             if spec_set is not None:

From 452128d5b745894e9e7f259312a6eb69dd333905 Mon Sep 17 00:00:00 2001
From: Robert Collins <robert.collins@cognite.com>
Date: Tue, 28 May 2024 11:38:19 +0200
Subject: [PATCH 2/3] Add regression test

---
 Lib/test/test_unittest/testmock/support.py   | 11 +++++++++++
 Lib/test/test_unittest/testmock/testpatch.py |  7 +++++++
 2 files changed, 18 insertions(+)

diff --git a/Lib/test/test_unittest/testmock/support.py b/Lib/test/test_unittest/testmock/support.py
index 49986d65dc47af6..6c535b7944f261e 100644
--- a/Lib/test/test_unittest/testmock/support.py
+++ b/Lib/test/test_unittest/testmock/support.py
@@ -14,3 +14,14 @@ def wibble(self): pass
 
 class X(object):
     pass
+
+# A standin for weurkzeug.local.LocalProxy - issue 119600
+def _inaccessible(*args, **kwargs):
+    raise AttributeError
+
+
+class OpaqueProxy:
+    __getattribute__ = _inaccessible
+
+
+g = OpaqueProxy()
diff --git a/Lib/test/test_unittest/testmock/testpatch.py b/Lib/test/test_unittest/testmock/testpatch.py
index be75fda7826af17..f26e74ce0bc1ba7 100644
--- a/Lib/test/test_unittest/testmock/testpatch.py
+++ b/Lib/test/test_unittest/testmock/testpatch.py
@@ -2045,6 +2045,13 @@ def test(): pass
         with self.assertRaises(TypeError):
             test()
 
+    def test_patch_proxy_object(self):
+        @patch("test.test_unittest.testmock.support.g", new_callable=MagicMock())
+        def test(_):
+            pass
+
+        test()
+
 
 if __name__ == '__main__':
     unittest.main()

From 7f422a3331f3b86cecf1f4ebc3a256bd532bb6bf Mon Sep 17 00:00:00 2001
From: Robert Collins <robert.collins@cognite.com>
Date: Mon, 10 Jun 2024 14:01:03 +0200
Subject: [PATCH 3/3] Add NEWS blurb

---
 .../next/Library/2024-06-10-14-00-40.gh-issue-119600.jJMf4C.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-06-10-14-00-40.gh-issue-119600.jJMf4C.rst

diff --git a/Misc/NEWS.d/next/Library/2024-06-10-14-00-40.gh-issue-119600.jJMf4C.rst b/Misc/NEWS.d/next/Library/2024-06-10-14-00-40.gh-issue-119600.jJMf4C.rst
new file mode 100644
index 000000000000000..04c9ca9c3fd737e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-06-10-14-00-40.gh-issue-119600.jJMf4C.rst
@@ -0,0 +1,2 @@
+Fix :func:`unittest.mock.patch` to not read attributes of the target when
+``new_callable`` is set. Patch by Robert Collins.