From caf65e3e55bbf7d60712beb9053ee51a134608b0 Mon Sep 17 00:00:00 2001
From: Thomas A Caswell <tcaswell@gmail.com>
Date: Tue, 31 Dec 2024 15:08:31 -0500
Subject: [PATCH] MNT: use copy.deepcopy to implement deepcopy method

We provide deepcopy and copy methods as a shortcut for users to avoid having to
import the copy module and call the required function.  Directly calling
`__deepcopy__` side-steps all of the memoization machinery and may lead to
incorrect results.
---
 lib/matplotlib/path.py       | 20 ++++++++++++++++++--
 lib/matplotlib/transforms.py |  8 +++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
index 5f5a0f3..eac8cbd 100644
--- a/lib/matplotlib/path.py
+++ b/lib/matplotlib/path.py
@@ -11,6 +11,7 @@ visualisation.
 
 import copy
 from functools import lru_cache
+import sys
 from weakref import WeakValueDictionary
 
 import numpy as np
@@ -282,11 +283,26 @@ class Path:
         readonly, even if the source `Path` is.
         """
         # Deepcopying arrays (vertices, codes) strips the writeable=False flag.
-        p = copy.deepcopy(super(), memo)
+        if sys.version_info >= (3, 14):
+            from copy import _reconstruct, _keep_alive
+            rv = super().__reduce_ex__(4)
+            assert memo is not None
+            p = _reconstruct(self, memo, *rv)
+            if memo is not None:
+                memo[id(self)] = p
+                _keep_alive(self, memo)
+
+        else:
+            p = copy.deepcopy(super(), memo)
         p._readonly = False
         return p
 
-    deepcopy = __deepcopy__
+    def deepcopy(self, memo=None):
+        """
+        Return a shallow copy of the `Path`, which will share the
+        vertices and codes with the source `Path`.
+        """
+        return copy.deepcopy(self, memo=memo)
 
     @classmethod
     def make_compound_path_from_polys(cls, XY):
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
index 2934b0a..74d3c68 100644
--- a/lib/matplotlib/transforms.py
+++ b/lib/matplotlib/transforms.py
@@ -38,6 +38,7 @@ of how to use transforms.
 import copy
 import functools
 import itertools
+import sys
 import textwrap
 import weakref
 import math
@@ -141,7 +142,12 @@ class TransformNode:
             for k, v in self._parents.items() if v is not None}
 
     def __copy__(self):
-        other = copy.copy(super())
+        if sys.version_info >= (3, 14):
+            from copy import _reconstruct
+            rv = super().__reduce_ex__(4)
+            other = _reconstruct(self, None, *rv)
+        else:
+            other = copy.copy(super())
         # If `c = a + b; a1 = copy(a)`, then modifications to `a1` do not
         # propagate back to `c`, i.e. we need to clear the parents of `a1`.
         other._parents = {}
-- 
2.48.1