From: Pieter Eendebak <pieter.eendebak@gmail.com>
Date: Mon, 17 Feb 2025 09:12:24 +0000 (+0100)
Subject: [3.13] gh-127750: Fix functools.singledispatchmethod()  (GH-130029)
X-Git-Tag: v3.13.3~263
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8f33c7ac17fe4c34ed3d051de17cfb702170874c;p=thirdparty%2FPython%2Fcpython.git

[3.13] gh-127750: Fix functools.singledispatchmethod()  (GH-130029)

Revert gh-107148
---

diff --git a/Lib/functools.py b/Lib/functools.py
index 2bc5053bd1b5..4c1175b815d6 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -958,9 +958,6 @@ class singledispatchmethod:
         self.dispatcher = singledispatch(func)
         self.func = func
 
-        import weakref # see comment in singledispatch function
-        self._method_cache = weakref.WeakKeyDictionary()
-
     def register(self, cls, method=None):
         """generic_method.register(cls, func) -> func
 
@@ -969,16 +966,6 @@ class singledispatchmethod:
         return self.dispatcher.register(cls, func=method)
 
     def __get__(self, obj, cls=None):
-        if self._method_cache is not None:
-            try:
-                _method = self._method_cache[obj]
-            except TypeError:
-                self._method_cache = None
-            except KeyError:
-                pass
-            else:
-                return _method
-
         dispatch = self.dispatcher.dispatch
         funcname = getattr(self.func, '__name__', 'singledispatchmethod method')
         def _method(*args, **kwargs):
@@ -991,9 +978,6 @@ class singledispatchmethod:
         _method.register = self.register
         update_wrapper(_method, self.func)
 
-        if self._method_cache is not None:
-            self._method_cache[obj] = _method
-
         return _method
 
     @property
diff --git a/Misc/NEWS.d/next/Library/2025-02-12-09-48-25.gh-issue-127750.ibhIZg.rst b/Misc/NEWS.d/next/Library/2025-02-12-09-48-25.gh-issue-127750.ibhIZg.rst
new file mode 100644
index 000000000000..a82805454e45
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-02-12-09-48-25.gh-issue-127750.ibhIZg.rst
@@ -0,0 +1,2 @@
+Remove broken :func:`functools.singledispatchmethod` caching introduced in
+:gh:`85160`.