From 860255319a75af63090caf9fc629c6ce11733a4d Mon Sep 17 00:00:00 2001
From: sobolevn <mail@sobolevn.me>
Date: Wed, 11 Oct 2023 11:00:39 +0300
Subject: [PATCH 1/2] gh-110682: Ignore `__match_args__` from
 `__intancecheck__` in protocols

---
 Lib/test/test_typing.py                       | 33 +++++++++++++++++++
 Lib/typing.py                                 |  3 +-
 ...-10-11-11-00-11.gh-issue-110682.bXRFaX.rst |  2 ++
 3 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index c24cf3bc776fc1..66812f317c7656 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -3801,6 +3801,39 @@ class E:
 
             self.assertIsInstance(E(), D)
 
+    def test_runtime_checkable_with_match_args(self):
+        @runtime_checkable
+        class P_regular(Protocol):
+            x: int
+            y: int
+
+        @runtime_checkable
+        class P_match(Protocol):
+            __match_args__ = ('x', 'y')
+            x: int
+            y: int
+
+        class Regular:
+            def __init__(self, x: int, y: int):
+                self.x = x
+                self.y = y
+
+        class WithMatch:
+            __match_args__ = ('x', 'y', 'z')
+            def __init__(self, x: int, y: int, z: int):
+                self.x = x
+                self.y = y
+                self.z = z
+
+        class Nope: ...
+
+        self.assertIsInstance(Regular(1, 2), P_regular)
+        self.assertIsInstance(Regular(1, 2), P_match)
+        self.assertIsInstance(WithMatch(1, 2, 3), P_regular)
+        self.assertIsInstance(WithMatch(1, 2, 3), P_match)
+        self.assertNotIsInstance(Nope(), P_regular)
+        self.assertNotIsInstance(Nope(), P_match)
+
     def test_supports_int(self):
         self.assertIsSubclass(int, typing.SupportsInt)
         self.assertNotIsSubclass(str, typing.SupportsInt)
diff --git a/Lib/typing.py b/Lib/typing.py
index d1f371377b88f8..14845b36028ca1 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1669,7 +1669,8 @@ class _TypingEllipsis:
 _SPECIAL_NAMES = frozenset({
     '__abstractmethods__', '__annotations__', '__dict__', '__doc__',
     '__init__', '__module__', '__new__', '__slots__',
-    '__subclasshook__', '__weakref__', '__class_getitem__'
+    '__subclasshook__', '__weakref__', '__class_getitem__',
+    '__match_args__',
 })
 
 # These special attributes will be not collected as protocol members.
diff --git a/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst b/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst
new file mode 100644
index 00000000000000..7a1e4be30bd89b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst
@@ -0,0 +1,2 @@
+Protocols used to check for ``__match_args__`` attribute in
+``__instancecheck__``. Now, this attribute is ignored.

From ac9f92ea1eebb40bfc2f49f9f0f80c629caa800c Mon Sep 17 00:00:00 2001
From: Nikita Sobolev <mail@sobolevn.me>
Date: Wed, 11 Oct 2023 16:43:52 +0300
Subject: [PATCH 2/2] Update
 Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
---
 .../Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst  | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst b/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst
index 7a1e4be30bd89b..b935d9a769c3c6 100644
--- a/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst
+++ b/Misc/NEWS.d/next/Library/2023-10-11-11-00-11.gh-issue-110682.bXRFaX.rst
@@ -1,2 +1,4 @@
-Protocols used to check for ``__match_args__`` attribute in
-``__instancecheck__``. Now, this attribute is ignored.
+:func:`runtime-checkable protocols <typing.runtime_checkable>` used
+to consider ``__match_args__`` a protocol member in
+``__instancecheck__`` if it was present on the protocol. Now, this attribute is
+ignored if it is present.