From 9151ed2fb2fa8c0648666cdfdb56e38ec3b15815 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Date: Fri, 24 Sep 2021 08:17:56 +1200
Subject: [PATCH] Return fstrings from `build_const_pathname`.

It's possible for `build_const_pathname` to be called when `rb_cString` is
still NULL. There is a fix-up step when `rb_cString` is initialized, but
it only applies to `fstring` instances.
---
 variable.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/variable.c b/variable.c
index aa1fdd022e..c6e1012bdd 100644
--- a/variable.c
+++ b/variable.c
@@ -202,8 +202,7 @@ build_const_pathname(VALUE head, VALUE tail)
     VALUE path = rb_str_dup(head);
     rb_str_cat2(path, "::");
     rb_str_append(path, tail);
-    OBJ_FREEZE(path);
-    return path;
+    return rb_fstring(path);
 }
 
 static VALUE