Check the class with `I` specifier of `mrb_get_args()`

Previously, the `I` specifier only checked if the object was `MRB_TT_ISTRUCT`.
So it was at risk of getting pointers to different C structs if multiple classes were to use the `MRB_TT_ISTRUCT` instance.

Change this behavior and change the C argument corresponding to the `I` specifier to `(void *, struct RClass)`.

This change is not compatible with the previous mruby.
Please note that if the user uses the previous specifications, `SIGSEGV` may occur or the machine stack may be destroyed.

resolve #5527

1 files changed, 2 insertions, 1 deletions

diff --git a/mrbgems/mruby-inline-struct/test/inline.c b/mrbgems/mruby-inline-struct/test/inline.c
index 6764b1af4..16d16fa4d 100644
--- a/mrbgems/mruby-inline-struct/test/inline.c
+++ b/mrbgems/mruby-inline-struct/test/inline.c
@@ -57,7 +57,8 @@ static mrb_value
 istruct_test_test_receive_direct(mrb_state *mrb, mrb_value self)
 {
   char *ptr;
-  mrb_get_args(mrb, "I", &ptr);
+  struct RClass *klass = mrb_class_get(mrb, "InlineStructTest");
+  mrb_get_args(mrb, "I", &ptr, klass);
   return mrb_bool_value(ptr[0] == 's');
 }