Allow accessing protected properties of managed dynamic objects

Author: jhonabreul

src/embed_tests/TestPropertyAccess.cs

@@ -960,6 +960,12 @@ public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, o
             public Dictionary<string, object> Properties { get { return _properties; } }
 
             public string NonDynamicProperty { get; set; }
+
+            protected string NonDynamicProtectedProperty { get; set; } = "Default value";
+
+            protected static string NonDynamicProtectedStaticProperty { get; set; } = "Default value";
+
+            protected string NonDynamicProtectedField = "Default value";
         }
 
         public class TestPerson : IComparable, IComparable<TestPerson>
@@ -1265,6 +1271,37 @@ def SetValue(self, fixture):
             }
         }
 
+        [TestCase("NonDynamicProtectedProperty")]
+        [TestCase("NonDynamicProtectedField")]
+        [TestCase("NonDynamicProtectedStaticProperty")]
+        public void TestSetPublicNonDynamicObjectProtectedPropertyToActualPropertyWorks(string attributeName)
+        {
+            var expected = "Non Dynamic Protected Property";
+            dynamic model = PyModule.FromString("module", $@"
+from clr import AddReference
+AddReference(""Python.EmbeddingTest"")
+AddReference(""System"")
+
+from datetime import datetime
+import System
+from Python.EmbeddingTest import *
+
+class RandomTestDynamicClass(TestPropertyAccess.DynamicFixture):
+    def SetValue(self):
+        self.{attributeName} = ""{expected}""
+").GetAttr("RandomTestDynamicClass").Invoke();
+
+            using (Py.GIL())
+            {
+                Assert.AreNotEqual(expected, model.GetAttr(attributeName).As<string>());
+
+                model.SetValue();
+
+                Assert.AreEqual(expected, model.GetAttr(attributeName).As<string>());
+                Assert.IsFalse(model.Properties.ContainsKey(attributeName).As<bool>());
+            }
+        }
+
         [Explicit]
         [TestCase(true, TestName = "CSharpGetPropertyPerformance")]
         [TestCase(false, TestName = "PythonGetPropertyPerformance")]

src/runtime/Types/DynamicClassObject.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Dynamic;
+using System.Reflection;
 using System.Runtime.CompilerServices;
 
 using RuntimeBinder = Microsoft.CSharp.RuntimeBinder;
@@ -87,7 +88,7 @@ public static NewReference tp_getattro(BorrowedReference ob, BorrowedReference k
                     // Do nothing, AttributeError was already raised in Python side and it was not cleared.
                 }
                 // Catch C# exceptions and raise them as Python exceptions.
-                catch(Exception exception)
+                catch (Exception exception)
                 {
                     Exceptions.Clear();
                     Exceptions.SetError(exception);
@@ -105,9 +106,12 @@ public static int tp_setattro(BorrowedReference ob, BorrowedReference key, Borro
             var clrObj = (CLRObject)GetManagedObject(ob)!;
             var name = Runtime.GetManagedString(key);
 
-            // If the key corresponds to a member of the class, we let the default implementation handle it.
+            // If the key corresponds to a valid property or field of the class, we let the default implementation handle it.
             var clrObjectType = clrObj.inst.GetType();
-            if (clrObjectType.GetMember(name).Length != 0)
+            var bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
+            var property = clrObjectType.GetProperty(name, bindingFlags);
+            var field = property == null ? clrObjectType.GetField(name, bindingFlags) : null;
+            if ((property != null && property.SetMethod != null) || field != null)
             {
                 return Runtime.PyObject_GenericSetAttr(ob, key, val);
             }