From 8e579e6552c7073fd2161fb650ff5e56aafc9573 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Wed, 24 May 2023 22:45:35 +0900
Subject: [PATCH] mruby-data/data.c (mrb_data_ref): check if reader has no
 argument

---
 mrbgems/mruby-data/src/data.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mrbgems/mruby-data/src/data.c b/mrbgems/mruby-data/src/data.c
index f25dc88d1..413c892d8 100644
--- a/mrbgems/mruby-data/src/data.c
+++ b/mrbgems/mruby-data/src/data.c
@@ -96,6 +96,10 @@ mrb_data_members(mrb_state *mrb, mrb_value obj)
 static mrb_value
 mrb_data_ref(mrb_state *mrb, mrb_value obj)
 {
+  mrb_int argc = mrb_get_argc(mrb);
+  if (argc != 0) {
+    mrb_argnum_error(mrb, argc, 0, 0);
+  }
   mrb_int i = mrb_integer(mrb_proc_cfunc_env_get(mrb, 0));
   mrb_value *ptr = RDATA_PTR(obj);