From 83656b56cb1b18531ed16584146156f2721e557d Mon Sep 17 00:00:00 2001
From: Jeongseop Lim <jseoplim@gmail.com>
Date: Sat, 8 Aug 2026 05:53:29 +0900
Subject: [PATCH] Reject a fifth argument to property()

PropertyArgs declared a fifth positional-or-keyword field, name, so the
derived arity was 0..=5 and property(None, None, None, None, None) built
a property object with the fifth argument stored in the __name__ slot.
CPython's property.__init__ is Argument Clinic generated with maxpos = 4
and the keyword list {fget, fset, fdel, doc}, so it rejects both that call
and property(name='x').

Drop the field. Nothing passed it: clone_property_with always supplied
None and copies the name separately, and the name slot is still filled by
__set_name__ and the __name__ setter.

Assisted-by: Claude Code:claude-opus-5
---
 crates/vm/src/builtins/property.rs       | 6 +-----
 extra_tests/snippets/builtin_property.py | 7 +++++++
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/crates/vm/src/builtins/property.rs b/crates/vm/src/builtins/property.rs
index cff5a8a60d0..65ae48222fa 100644
--- a/crates/vm/src/builtins/property.rs
+++ b/crates/vm/src/builtins/property.rs
@@ -1,7 +1,7 @@
 /*! Python `property` descriptor class.
 
 */
-use super::{PyStrRef, PyType};
+use super::PyType;
 use crate::common::lock::PyRwLock;
 use crate::function::{IntoFuncArgs, PosArgs};
 use crate::{
@@ -41,8 +41,6 @@ pub struct PropertyArgs {
     fdel: Option<PyObjectRef>,
     #[pyarg(any, default)]
     doc: Option<PyObjectRef>,
-    #[pyarg(any, default)]
-    name: Option<PyStrRef>,
 }
 
 impl GetDescriptor for PyProperty {
@@ -221,7 +219,6 @@ impl PyProperty {
             fset: new_setter.or_else(|| zelf.fset()),
             fdel: new_deleter.or_else(|| zelf.fdel()),
             doc,
-            name: None,
         };
 
         // Create new property using py_new and init
@@ -401,7 +398,6 @@ impl Initializer for PyProperty {
         *zelf.getter.write() = args.fget;
         *zelf.setter.write() = args.fset;
         *zelf.deleter.write() = args.fdel;
-        *zelf.name.write() = args.name.map(|a| a.as_object().to_owned());
         zelf.getter_doc.store(getter_doc, Ordering::Relaxed);
 
         Ok(())
diff --git a/extra_tests/snippets/builtin_property.py b/extra_tests/snippets/builtin_property.py
index de64e526228..397d41fb075 100644
--- a/extra_tests/snippets/builtin_property.py
+++ b/extra_tests/snippets/builtin_property.py
@@ -85,3 +85,10 @@ def foo(self):
 
 p2 = property("a", doc="pdoc")
 # assert p2.__doc__ == 'pdoc'
+
+
+# property() takes at most four arguments, and `name` is not one of them:
+# the name slot is filled by __set_name__ and the __name__ setter instead.
+assert_raises(TypeError, property, None, None, None, None, None)
+assert_raises(TypeError, property, "a", "b", "c", "d", "e")
+assert_raises(TypeError, property, name="x")