From 9420fc8ad6b30c3ff98b116a9bde5cd8cc91c5fa Mon Sep 17 00:00:00 2001
From: Jean Boussier <jean.boussier@gmail.com>
Date: Tue, 13 May 2025 19:15:11 +0200
Subject: [PATCH] [ruby/stringio] Add a comment to explicit RUBY_FL_USER2 |
 RUBY_FL_USER3 (https://github.com/ruby/stringio/pull/133)

This way when someone removes these flags from Ruby or update them,
they'll find this reference when greping.

Followup: https://github.com/ruby/stringio/pull/128

https://github.com/ruby/stringio/commit/fad26ee14b
---
 ext/stringio/stringio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index 4041537d25..26287dd1b8 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -1868,6 +1868,8 @@ strio_set_encoding(int argc, VALUE *argv, VALUE self)
     if (!NIL_P(ptr->string) && WRITABLE(self)
 #if (RUBY_API_VERSION_MAJOR == 3 && RUBY_API_VERSION_MINOR >= 4) || RUBY_API_VERSION_MAJOR >= 4
             // Do not attempt to modify chilled strings on Ruby 3.4+
+            // RUBY_FL_USER2 == STR_CHILLED_LITERAL
+            // RUBY_FL_USER3 == STR_CHILLED_SYMBOL_TO_S
             && !FL_TEST_RAW(ptr->string, RUBY_FL_USER2 | RUBY_FL_USER3)
 #endif
             ) {