avm2: Throw when using delete with XMLList operand (name)

core/src/avm2/activation.rs

@@ -1514,6 +1514,18 @@ impl<'a, 'gc> Activation<'a, 'gc> {
         }
 
         // main path for dynamic names
+        if multiname.has_lazy_name() {
+            let name_value = self.context.avm2.peek(0);
+            if matches!(name_value, Value::Object(Object::XmlListObject(_))) {
+                // ECMA-357 11.3.1 The delete Operator
+                // If the type of the operand is XMLList, then a TypeError exception is thrown.
+                return Err(Error::AvmError(type_error(
+                    self,
+                    "Error #1119: Delete operator is not supported with operand of type XMLList.",
+                    1119,
+                )?));
+            }
+        }
         let multiname = multiname.fill_with_runtime_params(self)?;
         let object = self.pop_stack();
         let object = object.coerce_to_object_or_typeerror(self, Some(&multiname))?;