From 725ffafd1318540d7cfa825e5b2b51ecc4157952 Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Feb 2026 00:05:15 +0900
Subject: [PATCH] Update `copy` module and `test_copy` from CPython v3.14.3
 (#7062)

---
 Lib/copy.py           | 58 ++++++++++++++-----------------------------
 Lib/test/test_copy.py | 14 ++++++-----
 2 files changed, 27 insertions(+), 45 deletions(-)

diff --git a/Lib/copy.py b/Lib/copy.py
index 2a4606246..c64fc0761 100644
--- a/Lib/copy.py
+++ b/Lib/copy.py
@@ -67,13 +67,15 @@ def copy(x):
 
     cls = type(x)
 
-    copier = _copy_dispatch.get(cls)
-    if copier:
-        return copier(x)
+    if cls in _copy_atomic_types:
+        return x
+    if cls in _copy_builtin_containers:
+        return cls.copy(x)
+
 
     if issubclass(cls, type):
         # treat it as a regular class:
-        return _copy_immutable(x)
+        return x
 
     copier = getattr(cls, "__copy__", None)
     if copier is not None:
@@ -98,23 +100,12 @@ def copy(x):
     return _reconstruct(x, None, *rv)
 
 
-_copy_dispatch = d = {}
-
-def _copy_immutable(x):
-    return x
-for t in (types.NoneType, int, float, bool, complex, str, tuple,
+_copy_atomic_types = {types.NoneType, int, float, bool, complex, str, tuple,
           bytes, frozenset, type, range, slice, property,
           types.BuiltinFunctionType, types.EllipsisType,
           types.NotImplementedType, types.FunctionType, types.CodeType,
-          weakref.ref):
-    d[t] = _copy_immutable
-
-d[list] = list.copy
-d[dict] = dict.copy
-d[set] = set.copy
-d[bytearray] = bytearray.copy
-
-del d, t
+          weakref.ref, super}
+_copy_builtin_containers = {list, dict, set, bytearray}
 
 def deepcopy(x, memo=None, _nil=[]):
     """Deep copy operation on arbitrary Python objects.
@@ -122,6 +113,11 @@ def deepcopy(x, memo=None, _nil=[]):
     See the module's __doc__ string for more info.
     """
 
+    cls = type(x)
+
+    if cls in _atomic_types:
+        return x
+
     d = id(x)
     if memo is None:
         memo = {}
@@ -130,14 +126,12 @@ def deepcopy(x, memo=None, _nil=[]):
         if y is not _nil:
             return y
 
-    cls = type(x)
-
     copier = _deepcopy_dispatch.get(cls)
     if copier is not None:
         y = copier(x, memo)
     else:
         if issubclass(cls, type):
-            y = _deepcopy_atomic(x, memo)
+            y = x # atomic copy
         else:
             copier = getattr(x, "__deepcopy__", None)
             if copier is not None:
@@ -168,26 +162,12 @@ def deepcopy(x, memo=None, _nil=[]):
         _keep_alive(x, memo) # Make sure x lives at least as long as d
     return y
 
+_atomic_types =  {types.NoneType, types.EllipsisType, types.NotImplementedType,
+          int, float, bool, complex, bytes, str, types.CodeType, type, range,
+          types.BuiltinFunctionType, types.FunctionType, weakref.ref, property}
+
 _deepcopy_dispatch = d = {}
 
-def _deepcopy_atomic(x, memo):
-    return x
-d[types.NoneType] = _deepcopy_atomic
-d[types.EllipsisType] = _deepcopy_atomic
-d[types.NotImplementedType] = _deepcopy_atomic
-d[int] = _deepcopy_atomic
-d[float] = _deepcopy_atomic
-d[bool] = _deepcopy_atomic
-d[complex] = _deepcopy_atomic
-d[bytes] = _deepcopy_atomic
-d[str] = _deepcopy_atomic
-d[types.CodeType] = _deepcopy_atomic
-d[type] = _deepcopy_atomic
-d[range] = _deepcopy_atomic
-d[types.BuiltinFunctionType] = _deepcopy_atomic
-d[types.FunctionType] = _deepcopy_atomic
-d[weakref.ref] = _deepcopy_atomic
-d[property] = _deepcopy_atomic
 
 def _deepcopy_list(x, memo, deepcopy=deepcopy):
     y = []
diff --git a/Lib/test/test_copy.py b/Lib/test/test_copy.py
index a065cc7b0..cfef24727 100644
--- a/Lib/test/test_copy.py
+++ b/Lib/test/test_copy.py
@@ -19,7 +19,7 @@ class TestCopy(unittest.TestCase):
 
     def test_exceptions(self):
         self.assertIs(copy.Error, copy.error)
-        self.assertTrue(issubclass(copy.Error, Exception))
+        self.assertIsSubclass(copy.Error, Exception)
 
     # The copy() method
 
@@ -371,6 +371,8 @@ class TestCopy(unittest.TestCase):
         self.assertIsNot(x, y)
         self.assertIsNot(x[0], y[0])
 
+    @support.skip_emscripten_stack_overflow()
+    @support.skip_wasi_stack_overflow()
     def test_deepcopy_reflexive_list(self):
         x = []
         x.append(x)
@@ -398,6 +400,8 @@ class TestCopy(unittest.TestCase):
         y = copy.deepcopy(x)
         self.assertIs(x, y)
 
+    @support.skip_emscripten_stack_overflow()
+    @support.skip_wasi_stack_overflow()
     def test_deepcopy_reflexive_tuple(self):
         x = ([],)
         x[0].append(x)
@@ -415,6 +419,8 @@ class TestCopy(unittest.TestCase):
         self.assertIsNot(x, y)
         self.assertIsNot(x["foo"], y["foo"])
 
+    @support.skip_emscripten_stack_overflow()
+    @support.skip_wasi_stack_overflow()
     def test_deepcopy_reflexive_dict(self):
         x = {}
         x['foo'] = x
@@ -666,7 +672,7 @@ class TestCopy(unittest.TestCase):
     def test_reduce_5tuple(self):
         class C(dict):
             def __reduce__(self):
-                return (C, (), self.__dict__, None, self.items())
+                return (C, (), self.__dict__, None, iter(self.items()))
             def __eq__(self, other):
                 return (dict(self) == dict(other) and
                         self.__dict__ == other.__dict__)
@@ -837,15 +843,12 @@ class TestCopy(unittest.TestCase):
         v[x] = y
         self.assertNotIn(x, u)
 
-
     def test_copy_weakkeydict(self):
         self._check_copy_weakdict(weakref.WeakKeyDictionary)
 
-
     def test_copy_weakvaluedict(self):
         self._check_copy_weakdict(weakref.WeakValueDictionary)
 
-
     def test_deepcopy_weakkeydict(self):
         class C(object):
             def __init__(self, i):
@@ -866,7 +869,6 @@ class TestCopy(unittest.TestCase):
         support.gc_collect()  # For PyPy or other GCs.
         self.assertEqual(len(v), 1)
 
-
     def test_deepcopy_weakvaluedict(self):
         class C(object):
             def __init__(self, i):