From 091478e76c45627426e9423a4e4305a27069e445 Mon Sep 17 00:00:00 2001
From: da-woods <dw-git@d-woods.co.uk>
Date: Tue, 2 Jun 2026 12:35:30 +0100
Subject: [PATCH] gh-58370 Document and test frozendict class matching
 behaviour

Frozendict has `_Py_TPFLAGS_MATCH_SELF` set so works correctly
with the single-arg class matching. However it isn't documented
in the list of classes this works with and it isn't tested.

The test is some way below the other similar tests but anything
else would need a large renumbering
---
 Doc/reference/compound_stmts.rst | 1 +
 Lib/test/test_patma.py           | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst
index 63baefd33e88c50..71bfb608dda7283 100644
--- a/Doc/reference/compound_stmts.rst
+++ b/Doc/reference/compound_stmts.rst
@@ -1172,6 +1172,7 @@ subject value:
    * :class:`bytes`
    * :class:`dict`
    * :class:`float`
+   * :class:`frozendict`
    * :class:`frozenset`
    * :class:`int`
    * :class:`list`
diff --git a/Lib/test/test_patma.py b/Lib/test/test_patma.py
index 29cce4ee6d271ff..52b36611e40a443 100644
--- a/Lib/test/test_patma.py
+++ b/Lib/test/test_patma.py
@@ -2852,6 +2852,15 @@ def test_patma_266(self):
         self.assertEqual(x, 0)
         self.assertEqual(y, 1)
 
+    def test_patma_267(self):
+        x = frozendict()
+        match x:
+            case frozendict(z):
+                y = 0
+        self.assertEqual(x, frozendict())
+        self.assertEqual(y, 0)
+        self.assertIs(z, x)
+
     def test_patma_runtime_checkable_protocol(self):
         # Runtime-checkable protocol
         from typing import Protocol, runtime_checkable