allow Python to overwrite .NET methods

lostmsu · lostmsu · commit 70b8c048328a · 2021-09-05T14:20:42.000-07:00
diff --git a/src/embed_tests/CallableObject.cs b/src/embed_tests/CallableObject.cs
@@ -0,0 +1,39 @@
+using NUnit.Framework;
+
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    class CallableObject
+    {
+        [OneTimeSetUp]
+        public void SetUp()
+        {
+            PythonEngine.Initialize();
+        }
+
+        [OneTimeTearDown]
+        public void Dispose()
+        {
+            PythonEngine.Shutdown();
+        }
+
+        [Test]
+        public void PythonCanOverwriteMethods()
+        {
+            var obj = new PublicCallMethod();
+            using var _ = Py.GIL();
+            using var scope = Py.CreateScope();
+            scope.Set("o", obj);
+            scope.Exec("orig_call = o.Call");
+            scope.Exec("o.Call = lambda a: orig_call(a*7)");
+            int result = scope.Eval<int>("o.Call(5)");
+            Assert.AreEqual(105, result);
+        }
+
+        class PublicCallMethod
+        {
+            public int Call(int arg) => 3 * arg;
+        }
+    }
+}
diff --git a/src/runtime/extensiontype.cs b/src/runtime/extensiontype.cs
@@ -87,18 +87,6 @@ public static int tp_setattro(IntPtr ob, IntPtr key, IntPtr val)
             return -1;
         }
 
-
-        /// <summary>
-        /// Default __set__ implementation - this prevents descriptor instances
-        /// being silently replaced in a type __dict__ by default __setattr__.
-        /// </summary>
-        public static int tp_descr_set(IntPtr ds, IntPtr ob, IntPtr val)
-        {
-            Exceptions.SetError(Exceptions.AttributeError, "attribute is read-only");
-            return -1;
-        }
-
-
         public static void tp_dealloc(IntPtr ob)
         {
             // Clean up a Python instance of this extension type. This
diff --git a/tests/test_method.py b/tests/test_method.py
@@ -6,39 +6,6 @@
 import pytest
 from Python.Test import MethodTest
 
-
-def test_instance_method_descriptor():
-    """Test instance method descriptor behavior."""
-
-    with pytest.raises(AttributeError):
-        MethodTest().PublicMethod = 0
-
-    with pytest.raises(AttributeError):
-        MethodTest.PublicMethod = 0
-
-    with pytest.raises(AttributeError):
-        del MethodTest().PublicMethod
-
-    with pytest.raises(AttributeError):
-        del MethodTest.PublicMethod
-
-
-def test_static_method_descriptor():
-    """Test static method descriptor behavior."""
-
-    with pytest.raises(AttributeError):
-        MethodTest().PublicStaticMethod = 0
-
-    with pytest.raises(AttributeError):
-        MethodTest.PublicStaticMethod = 0
-
-    with pytest.raises(AttributeError):
-        del MethodTest().PublicStaticMethod
-
-    with pytest.raises(AttributeError):
-        del MethodTest.PublicStaticMethod
-
-
 def test_public_instance_method():
     """Test public instance method visibility."""
     ob = MethodTest()
