From 1969100fb47457e8770e3eabe078c866f44c3669 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Mon, 14 Apr 2025 17:51:22 +0900
Subject: [PATCH] variable.c (mrb_vm_get_const): seek singleton class
 superclass; fix #6506

Also ensure we don't revive #2515, #3003, #3598
---
 src/variable.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/variable.c b/src/variable.c
index f897aabc1..317d4acfa 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -841,6 +841,11 @@ mrb_vm_const_get(mrb_state *mrb, mrb_sym sym)
     }
   }
   if (c->tt == MRB_TT_SCLASS) {
+    v = const_get_nohook(mrb, c, sym, TRUE);
+    if (!mrb_undef_p(v)) {
+      return v;
+    }
+
     mrb_value klass;
     for (c2 = c; c2 && c2->tt == MRB_TT_SCLASS; c2 = mrb_class_ptr(klass)) {
       if (!iv_get(mrb, class_iv_ptr(c2), MRB_SYM(__attached__), &klass)) {