Merge remote-tracking branch 'upstream/master'

1 files changed, 9 insertions, 4 deletions

diff --git a/src/class.c b/src/class.c
index 4264129b6..f94f9a933 100644
--- a/src/class.c
+++ b/src/class.c
@@ -1047,6 +1047,9 @@ mrb_instance_new(mrb_state *mrb, mrb_value cv)
   mrb_value *argv;
   int argc;
 
+  if (c->tt == MRB_TT_SCLASS)
+    mrb_raise(mrb, E_TYPE_ERROR, "can't create instance of singleton class");
+
   if (ttype == 0) ttype = MRB_TT_OBJECT;
   o = (struct RObject*)mrb_obj_alloc(mrb, ttype, c);
   obj = mrb_obj_value(o);
@@ -1414,14 +1417,17 @@ mrb_mod_alias(mrb_state *mrb, mrb_value mod)
   return mrb_nil_value();
 }
 
-
 static void
 undef_method(mrb_state *mrb, struct RClass *c, mrb_sym a)
 {
   mrb_value m;
 
-  MRB_SET_VALUE(m, MRB_TT_PROC, value.p, 0);
-  mrb_define_method_vm(mrb, c, a, m);
+  if (!mrb_obj_respond_to(c, a)) {
+    mrb_name_error(mrb, a, "undefined method '%S' for class '%S'", mrb_sym2str(mrb, a), mrb_obj_value(c));
+  } else {
+    MRB_SET_VALUE(m, MRB_TT_PROC, value.p, 0);
+    mrb_define_method_vm(mrb, c, a, m);
+  }
 }
 
 void
@@ -1873,7 +1879,6 @@ mrb_init_class(mrb_state *mrb)
   mrb_name_class(mrb, mod, mrb_intern(mrb, "Module"));
   mrb_name_class(mrb, cls, mrb_intern(mrb, "Class"));
 
-  mrb_undef_method(mrb, mod, "new");
   MRB_SET_INSTANCE_TT(cls, MRB_TT_CLASS);
   mrb_define_method(mrb, bob, "initialize",              mrb_bob_init,             MRB_ARGS_NONE());
   mrb_define_method(mrb, bob, "!",                       mrb_bob_not,              MRB_ARGS_NONE());