pythonnet · lostmsu · Jan 4, 2022 · Dec 28, 2021
diff --git a/src/embed_tests/Inheritance.cs b/src/embed_tests/Inheritance.cs
@@ -119,6 +119,15 @@ public void BaseClearIsCalled()
             scope.Set("exn", null);
             Assert.AreEqual(1, msg.Refcount);
         }
+
+        // https://github.com/pythonnet/pythonnet/issues/1455
+        [Test]
+        public void PropertyAccessorOverridden()
+        {
+            using var derived = new PropertyAccessorDerived().ToPython();
+            derived.SetAttr(nameof(PropertyAccessorDerived.VirtualProp), "hi".ToPython());
+            Assert.AreEqual("HI", derived.GetAttr(nameof(PropertyAccessorDerived.VirtualProp)).As<string>());
+        }
     }
 
     class ExtraBaseTypeProvider : IPythonBaseTypeProvider
@@ -192,6 +201,18 @@ public int XProp
         }
     }
 
+    public class PropertyAccessorBase
+    {
+        public virtual string VirtualProp { get; set; }
+    }
+
+    public class PropertyAccessorIntermediate: PropertyAccessorBase { }
+
+    public class PropertyAccessorDerived: PropertyAccessorIntermediate
+    {
+        public override string VirtualProp { set => base.VirtualProp = value.ToUpperInvariant(); }
+    }
+
     public class ContainerClass
     {
         public void BaseMethod() { }

diff --git a/src/runtime/ReflectionUtil.cs b/src/runtime/ReflectionUtil.cs
@@ -0,0 +1,56 @@
+namespace Python.Runtime;
+
+using System;
+using System.Reflection;
+
+static class ReflectionUtil
+{
+    public static MethodInfo? GetBaseGetMethod(this PropertyInfo property, bool nonPublic)
+    {
+        if (property is null) throw new ArgumentNullException(nameof(property));
+
+        Type baseType = property.DeclaringType.BaseType;
+        BindingFlags bindingFlags = property.GetBindingFlags();
+
+        while (baseType is not null)
+        {
+            var baseProperty = baseType.GetProperty(property.Name, bindingFlags | BindingFlags.DeclaredOnly);
+            var accessor = baseProperty?.GetGetMethod(nonPublic);
+            if (accessor is not null)
+                return accessor;
+
+            baseType = baseType.BaseType;
+        }
+
+        return null;
+    }
+
+    public static MethodInfo? GetBaseSetMethod(this PropertyInfo property, bool nonPublic)
+    {
+        if (property is null) throw new ArgumentNullException(nameof(property));
+
+        Type baseType = property.DeclaringType.BaseType;
+        BindingFlags bindingFlags = property.GetBindingFlags();
+
+        while (baseType is not null)
+        {
+            var baseProperty = baseType.GetProperty(property.Name, bindingFlags | BindingFlags.DeclaredOnly);
+            var accessor = baseProperty?.GetSetMethod(nonPublic);
+            if (accessor is not null)
+                return accessor;
+
+            baseType = baseType.BaseType;
+        }
+
+        return null;
+    }
+
+    public static BindingFlags GetBindingFlags(this PropertyInfo property)
+    {
+        var accessor = property.GetMethod ?? property.SetMethod;
+        BindingFlags flags = default;
+        flags |= accessor.IsStatic ? BindingFlags.Static : BindingFlags.Instance;
+        flags |= accessor.IsPublic ? BindingFlags.Public : BindingFlags.NonPublic;
+        return flags;
+    }
+}
diff --git a/src/runtime/propertyobject.cs b/src/runtime/propertyobject.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Reflection;
+using System.Runtime.Serialization;
 
 namespace Python.Runtime
 {
@@ -8,17 +9,25 @@ namespace Python.Runtime
     /// Implements a Python descriptor type that manages CLR properties.
     /// </summary>
     [Serializable]
-    internal class PropertyObject : ExtensionType
+    internal class PropertyObject : ExtensionType, IDeserializationCallback
     {
         internal MaybeMemberInfo<PropertyInfo> info;
-        private MaybeMethodInfo getter;
-        private MaybeMethodInfo setter;
+        [NonSerialized]
+        private MethodInfo? getter;
+        [NonSerialized]
+        private MethodInfo? setter;
 
         public PropertyObject(PropertyInfo md)
         {
-            getter = md.GetGetMethod(true);
-            setter = md.GetSetMethod(true);
             info = new MaybeMemberInfo<PropertyInfo>(md);
+            CacheAccessors();
+        }
+
+        void CacheAccessors()
+        {
+            PropertyInfo md = info.Value;
+            getter = md.GetGetMethod(true) ?? md.GetBaseGetMethod(true);
+            setter = md.GetSetMethod(true) ?? md.GetBaseSetMethod(true);
         }
 
 
@@ -35,7 +44,7 @@ public static NewReference tp_descr_get(BorrowedReference ds, BorrowedReference
                 return Exceptions.RaiseTypeError(self.info.DeletedMessage);
             }
             var info = self.info.Value;
-            MethodInfo getter = self.getter.UnsafeValue;
+            MethodInfo? getter = self.getter;
             object result;
 
 
@@ -70,7 +79,7 @@ public static NewReference tp_descr_get(BorrowedReference ds, BorrowedReference
 
             try
             {
-                result = info.GetValue(co.inst, null);
+                result = getter.Invoke(co.inst, Array.Empty<object>());
                 return Converter.ToPython(result, info.PropertyType);
             }
             catch (Exception e)
@@ -100,7 +109,7 @@ public static int tp_descr_set(BorrowedReference ds, BorrowedReference ob, Borro
             }
             var info = self.info.Value;
 
-            MethodInfo setter = self.setter.UnsafeValue;
+            MethodInfo? setter = self.setter;
 
             if (val == null)
             {
@@ -141,7 +150,7 @@ public static int tp_descr_set(BorrowedReference ds, BorrowedReference ob, Borro
                         Exceptions.RaiseTypeError("invalid target");
                         return -1;
                     }
-                    info.SetValue(co.inst, newval, null);
+                    setter.Invoke(co.inst, new object?[] { newval });
                 }
                 else
                 {
@@ -169,5 +178,13 @@ public static NewReference tp_repr(BorrowedReference ob)
             var self = (PropertyObject)GetManagedObject(ob)!;
             return Runtime.PyString_FromString($"<property '{self.info}'>");
         }
+
+        void IDeserializationCallback.OnDeserialization(object sender)
+        {
+            if (info.Valid)
+            {
+                CacheAccessors();
+            }
+        }
     }
 }