gh-117765: Improve documentation for mocker.patch.dict

Doc/library/unittest.mock.rst

@@ -1624,7 +1624,8 @@ patch.dict
 .. function:: patch.dict(in_dict, values=(), clear=False, **kwargs)
 
     Patch a dictionary, or dictionary like object, and restore the dictionary
-    to its original state after the test.
+    to its original state after the test, where the restored dictionary is a
+    copy of the dictionary as it was before the test.
 
     *in_dict* can be a dictionary or a mapping like container. If it is a
     mapping then it must at least support getting, setting and deleting items

Lib/unittest/mock.py

@@ -1829,7 +1829,8 @@ def patch(
 class _patch_dict(object):
     """
     Patch a dictionary, or dictionary like object, and restore the dictionary
-    to its original state after the test.
+    to its original state after the test, where the restored dictionary is
+    a copy of the dictionary as it was before the test.
 
     `in_dict` can be a dictionary or a mapping like container. If it is a
     mapping then it must at least support getting, setting and deleting items

Misc/NEWS.d/next/Documentation/2024-07-14-12-25-53.gh-issue-117765.YFMOUv.rst

@@ -0,0 +1 @@
+Improved documentation for :func:`unittest.mock.patch.dict`