From ed7eb6f7f19bd26e984bc3be065243f8ead38b25 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 9 Jun 2022 09:53:43 -0400
Subject: [PATCH] dont transfer __weakref__ to regenerated class

Repaired a deprecation warning class decorator that was preventing key
objects such as :class:`_engine.Connection` from having a proper
``__weakref__`` attribute, causing operations like Python standard library
``inspect.getmembers()`` to fail.

Fixes: #8115
Change-Id: Ifd0bc2325fb9dc9e1431998c308b7fc081968373
(cherry picked from commit cc7cc3c9ec73055703acc78c8d92eb0242e5cd20)
---
 doc/build/changelog/unreleased_14/8115.rst |  9 +++++
 lib/sqlalchemy/util/deprecations.py        |  1 +
 test/base/test_warnings.py                 | 46 ++++++++++++++++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 doc/build/changelog/unreleased_14/8115.rst

diff --git a/doc/build/changelog/unreleased_14/8115.rst b/doc/build/changelog/unreleased_14/8115.rst
new file mode 100644
index 0000000000..856a76a42e
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/8115.rst
@@ -0,0 +1,9 @@
+.. change::
+    :tags: bug, engine
+    :tickets: 8115
+
+    Repaired a deprecation warning class decorator that was preventing key
+    objects such as :class:`_engine.Connection` from having a proper
+    ``__weakref__`` attribute, causing operations like Python standard library
+    ``inspect.getmembers()`` to fail.
+
diff --git a/lib/sqlalchemy/util/deprecations.py b/lib/sqlalchemy/util/deprecations.py
index fe2f968040..b61516d85c 100644
--- a/lib/sqlalchemy/util/deprecations.py
+++ b/lib/sqlalchemy/util/deprecations.py
@@ -356,6 +356,7 @@ def _decorate_cls_with_warning(
             clsdict = dict(cls.__dict__)
             clsdict["__doc__"] = doc
             clsdict.pop("__dict__", None)
+            clsdict.pop("__weakref__", None)
             cls = type(cls.__name__, cls.__bases__, clsdict)
             if constructor is not None:
                 constructor_fn = clsdict[constructor]
diff --git a/test/base/test_warnings.py b/test/base/test_warnings.py
index 0cbab7f282..be34f958b2 100644
--- a/test/base/test_warnings.py
+++ b/test/base/test_warnings.py
@@ -1,6 +1,9 @@
+from sqlalchemy import testing
+from sqlalchemy.exc import SADeprecationWarning
 from sqlalchemy.testing import eq_
 from sqlalchemy.testing import expect_deprecated
 from sqlalchemy.testing import fixtures
+from sqlalchemy.util.deprecations import _decorate_cls_with_warning
 from sqlalchemy.util.deprecations import warn_deprecated_limited
 from sqlalchemy.util.langhelpers import _hash_limit_string
 
@@ -34,3 +37,46 @@ class WarnDeprecatedLimitedTest(fixtures.TestBase):
 
         eq_(len(printouts), occurrences)
         eq_(len(messages), cap)
+
+
+class ClsWarningTest(fixtures.TestBase):
+    @testing.fixture
+    def dep_cls_fixture(self):
+        class Connectable(object):
+            """a docstring"""
+
+            some_member = "foo"
+
+        Connectable = _decorate_cls_with_warning(
+            Connectable,
+            None,
+            SADeprecationWarning,
+            "a message",
+            "2.0",
+            "another message",
+        )
+
+        return Connectable
+
+    def test_dep_inspectable(self, dep_cls_fixture):
+        """test #8115"""
+
+        import inspect
+
+        class PlainClass(object):
+            some_member = "bar"
+
+        pc_keys = dict(inspect.getmembers(PlainClass()))
+        insp_keys = dict(inspect.getmembers(dep_cls_fixture()))
+
+        assert set(insp_keys).intersection(
+            (
+                "__class__",
+                "__doc__",
+                "__eq__",
+                "__dict__",
+                "__weakref__",
+                "some_member",
+            )
+        )
+        eq_(set(pc_keys), set(insp_keys))
-- 
2.47.2