Ensure JSProxy correctness for PrototypeIterator uses

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 289f7d92336ba39e952fe188689764e182b1b812..393e2e29b4007b9ffbb3f9aaeadaf6aca45af793 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -3747,6 +3747,7 @@ Local<Object> v8::Object::FindInstanceInPrototypeChain(
       return Local<Object>();
     }
   }
+  // IsTemplateFor() ensures that iter.GetCurrent() can't be a Proxy here.
   return Utils::ToLocal(i::handle(iter.GetCurrent<i::JSObject>(), isolate));
 }
 
@@ -4125,13 +4126,14 @@ MaybeLocal<Value> v8::Object::GetRealNamedPropertyInPrototypeChain(
     Local<Context> context, Local<Name> key) {
   PREPARE_FOR_EXECUTION(
       context, "v8::Object::GetRealNamedPropertyInPrototypeChain()", Value);
-  auto self = Utils::OpenHandle(this);
-  auto key_obj = Utils::OpenHandle(*key);
+  i::Handle<i::JSObject> self = Utils::OpenHandle(this);
+  i::Handle<i::Name> key_obj = Utils::OpenHandle(*key);
   i::PrototypeIterator iter(isolate, self);
   if (iter.IsAtEnd()) return MaybeLocal<Value>();
-  auto proto = i::PrototypeIterator::GetCurrent(iter);
+  i::Handle<i::JSReceiver> proto =
+      i::PrototypeIterator::GetCurrent<i::JSReceiver>(iter);
   i::LookupIterator it = i::LookupIterator::PropertyOrElement(
-      isolate, self, key_obj, i::Handle<i::JSReceiver>::cast(proto),
+      isolate, self, key_obj, proto,
       i::LookupIterator::PROTOTYPE_CHAIN_SKIP_INTERCEPTOR);
   Local<Value> result;
   has_pending_exception = !ToLocal<Value>(i::Object::GetProperty(&it), &result);
@@ -4155,22 +4157,20 @@ v8::Object::GetRealNamedPropertyAttributesInPrototypeChain(
   PREPARE_FOR_EXECUTION_PRIMITIVE(
       context, "v8::Object::GetRealNamedPropertyAttributesInPrototypeChain()",
       PropertyAttribute);
-  auto self = Utils::OpenHandle(this);
-  auto key_obj = Utils::OpenHandle(*key);
+  i::Handle<i::JSObject> self = Utils::OpenHandle(this);
+  i::Handle<i::Name> key_obj = Utils::OpenHandle(*key);
   i::PrototypeIterator iter(isolate, self);
   if (iter.IsAtEnd()) return Nothing<PropertyAttribute>();
-  auto proto = i::PrototypeIterator::GetCurrent(iter);
+  i::Handle<i::JSReceiver> proto =
+      i::PrototypeIterator::GetCurrent<i::JSReceiver>(iter);
   i::LookupIterator it = i::LookupIterator::PropertyOrElement(
-      isolate, self, key_obj, i::Handle<i::JSReceiver>::cast(proto),
+      isolate, self, key_obj, proto,
       i::LookupIterator::PROTOTYPE_CHAIN_SKIP_INTERCEPTOR);
-  auto result = i::JSReceiver::GetPropertyAttributes(&it);
+  Maybe<PropertyAttributes> result = i::JSReceiver::GetPropertyAttributes(&it);
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(PropertyAttribute);
   if (!it.IsFound()) return Nothing<PropertyAttribute>();
-  if (result.FromJust() == ABSENT) {
-    return Just(static_cast<PropertyAttribute>(NONE));
-  }
-  return Just<PropertyAttribute>(
-      static_cast<PropertyAttribute>(result.FromJust()));
+  if (result.FromJust() == ABSENT) return Just(None);
+  return Just(static_cast<PropertyAttribute>(result.FromJust()));
 }