Implement property.__name__ attribute (RustPython#6230)

* Implement property.__name__ attribute

Add getter and setter for the __name__ attribute on property objects.
The getter returns the explicitly set name if available, otherwise
falls back to the getter function's __name__. Raises AttributeError
if no name is available, matching CPython 3.13 behavior.

The implementation handles edge cases:
- Returns None when explicitly set to None
- Propagates non-AttributeError exceptions from getter's __getattr__
- Raises property-specific AttributeError when getter lacks __name__

This fix enables test_property_name in test_property.py to pass.

* Refactor to use get_property_name in __name__ implementation

Consolidate duplicate logic by making name_getter() use the existing
get_property_name() helper method. This eliminates code duplication
and improves maintainability.

Changes:
- Update get_property_name() to return PyResult<Option<PyObjectRef>>
  to properly handle and propagate non-AttributeError exceptions
- Simplify name_getter() to delegate to get_property_name()
- Update format_property_error() to handle the new return type

This addresses review feedback about the relationship between
get_property_name() and __name__ implementation.

* style comment

Author: ever0de

Lib/test/test_property.py

@@ -201,7 +201,6 @@ def test_gh_115618(self):
         self.assertIsNone(prop.fdel)
         self.assertAlmostEqual(gettotalrefcount() - refs_before, 0, delta=10)
 
-    @unittest.expectedFailure # TODO: RUSTPYTHON
     def test_property_name(self):
         def getter(self):
             return 42

vm/src/builtins/property.rs

@@ -67,20 +67,30 @@ impl GetDescriptor for PyProperty {
 #[pyclass(with(Constructor, Initializer, GetDescriptor), flags(BASETYPE))]
 impl PyProperty {
     // Helper method to get property name
-    fn get_property_name(&self, vm: &VirtualMachine) -> Option<PyObjectRef> {
+    // Returns the name if available, None if not found, or propagates errors
+    fn get_property_name(&self, vm: &VirtualMachine) -> PyResult<Option<PyObjectRef>> {
         // First check if name was set via __set_name__
         if let Some(name) = self.name.read().as_ref() {
-            return Some(name.clone());
+            return Ok(Some(name.clone()));
         }
 
-        // Otherwise try to get __name__ from getter
-        if let Some(getter) = self.getter.read().as_ref()
-            && let Ok(name) = getter.get_attr("__name__", vm)
-        {
-            return Some(name);
-        }
+        let getter = self.getter.read();
+        let Some(getter) = getter.as_ref() else {
+            return Ok(None);
+        };
 
-        None
+        match getter.get_attr("__name__", vm) {
+            Ok(name) => Ok(Some(name)),
+            Err(e) => {
+                // If it's an AttributeError from the getter, return None
+                // Otherwise, propagate the original exception (e.g., RuntimeError)
+                if e.class().is(vm.ctx.exceptions.attribute_error) {
+                    Ok(None)
+                } else {
+                    Err(e)
+                }
+            }
+        }
     }
 
     // Descriptor methods
@@ -143,6 +153,21 @@ impl PyProperty {
         self.deleter.read().clone()
     }
 
+    #[pygetset(name = "__name__")]
+    fn name_getter(&self, vm: &VirtualMachine) -> PyResult {
+        match self.get_property_name(vm)? {
+            Some(name) => Ok(name),
+            None => Err(
+                vm.new_attribute_error("'property' object has no attribute '__name__'".to_owned())
+            ),
+        }
+    }
+
+    #[pygetset(name = "__name__", setter)]
+    fn name_setter(&self, value: PyObjectRef) {
+        *self.name.write() = Some(value);
+    }
+
     fn doc_getter(&self) -> Option<PyObjectRef> {
         self.doc.read().clone()
     }
@@ -288,7 +313,7 @@ impl PyProperty {
         error_type: &str,
         vm: &VirtualMachine,
     ) -> PyResult<String> {
-        let prop_name = self.get_property_name(vm);
+        let prop_name = self.get_property_name(vm)?;
         let obj_type = obj.class();
         let qualname = obj_type.__qualname__(vm);