don't try to call generic getattr before calling user-supplied override

lostmsu · lostmsu · commit 12c5539c0dbe · 2019-09-11T11:57:32.000-07:00
diff --git a/src/embed_tests/TestInstanceWrapping.cs b/src/embed_tests/TestInstanceWrapping.cs
@@ -123,6 +123,12 @@ public void IntOrStr(string arg) =>
             public void BaseOrDerived(Derived _) => this.Value = Derived;
 
             public bool TryGetAttr(string name, out PyObject value) {
+                using (var self = this.ToPython()) {
+                    if (GetAttr.TryGetBaseAttr(self, name, out value)
+                        || GetAttr.GenericGetAttr(self, name, out value))
+                        return true;
+                }
+
                 value = GetAttrFallbackValue.ToPython();
                 return true;
             }
diff --git a/src/runtime/slots.cs b/src/runtime/slots.cs
@@ -12,8 +12,8 @@ public interface IGetAttr {
 
     static class SlotOverrides {
         public static IntPtr tp_getattro(IntPtr ob, IntPtr key) {
-            IntPtr genericResult = Runtime.PyObject_GenericGetAttr(ob, key);
-            if (genericResult != IntPtr.Zero || !Runtime.PyString_Check(key)) {
+            if (!Runtime.PyString_Check(key)) {
+                IntPtr genericResult = Runtime.PyObject_GenericGetAttr(ob, key);
                 return genericResult;
             }
 
@@ -43,7 +43,7 @@ public static bool TryGetBaseAttr(PyObject self, string name, out PyObject resul
             if (name == null) throw new ArgumentNullException(nameof(name));
 
             using (var super = new PyObject(Runtime.PySuper))
-            using (var @class = self.GetAttr("__class__"))
+            using (var @class = self.GetPythonType())
             using (var @base = super.Invoke(@class, self)) {
                 if (!@base.HasAttr(getAttr)) {
                     result = null;
@@ -56,5 +56,25 @@ public static bool TryGetBaseAttr(PyObject self, string name, out PyObject resul
                 }
             }
         }
+
+        public static bool GenericGetAttr(PyObject self, string name, out PyObject result) {
+            if (self == null) throw new ArgumentNullException(nameof(self));
+            if (name == null) throw new ArgumentNullException(nameof(name));
+
+            using (var pyName = name.ToPython()) {
+                IntPtr pyResult = Runtime.PyObject_GenericGetAttr(self.Handle, pyName.Handle);
+                if (pyResult == IntPtr.Zero) {
+                    result = null;
+                    if (!PythonException.Matches(Exceptions.AttributeError)) {
+                        throw PythonException.FromPyErr();
+                    }
+
+                    Exceptions.Clear();
+                    return false;
+                }
+                result = new PyObject(Runtime.SelfIncRef(pyResult));
+                return true;
+            }
+        }
     }
 }
