From 4b9d10b8330b5072993f2c32eaf701c5c1aa7e55 Mon Sep 17 00:00:00 2001
From: Zack Deveau <zack.ref@gmail.com>
Date: Tue, 29 Nov 2022 14:40:43 -0500
Subject: [PATCH] struct.c (struct_ivar_get): add conditional for potential
 Qnil returned by rb_class_superclass

struct_ivar_get recently started using rb_class_superclass to
resolve super instead of RCLASS_SUPER. This change made
Qnil a possible case we need to return from within the
struct_ivar_get for loop.
---
 struct.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/struct.c b/struct.c
index 10e5209fb9..9f7277e6b2 100644
--- a/struct.c
+++ b/struct.c
@@ -48,7 +48,7 @@ struct_ivar_get(VALUE c, ID id)
 
     for (;;) {
         c = rb_class_superclass(c);
-        if (c == 0 || c == rb_cStruct || c == rb_cData)
+        if (c == 0 || c == rb_cStruct || c == rb_cData || c == Qnil)
             return Qnil;
         RUBY_ASSERT(RB_TYPE_P(c, T_CLASS));
         ivar = rb_attr_get(c, id);