vm_eval.c: fix for rb_check_funcall_default

* vm_eval.c (check_funcall_missing): basic_obj_respond_to_missing
  returns Qundef if respond_to_missing is not redefined.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58984 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm_eval.c

@@ -404,7 +404,7 @@ check_funcall_missing(rb_thread_t *th, VALUE klass, VALUE recv, ID mid, int argc
 
     ret = basic_obj_respond_to_missing(th, klass, recv,
 				       ID2SYM(mid), PRIV);
-    if (!RTEST(ret)) return def;
+    if (!RTEST(ret) || ret == Qundef) return def;
     args.respond = respond > 0;
     args.respond_to_missing = (ret != Qundef);
     ret = def;