From 38af38edcbceb9d17aaf84420008fe839f77e42f Mon Sep 17 00:00:00 2001
From: Luke Gruber <luke.gru@gmail.com>
Date: Fri, 16 Feb 2024 14:08:39 -0500
Subject: [PATCH] Fix ractor move of unshareable frozen objects

These objects didn't retain their frozen status after the move

Bug [#19408]
---
 bootstraptest/test_ractor.rb | 11 +++++++++++
 ractor.c                     |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index 08f269dda9..b3ab7f607c 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -752,6 +752,17 @@ assert_equal '[0, 1]', %q{
   end
 }
 
+# unshareable frozen objects should still be frozen in new ractor after move
+assert_equal 'true', %q{
+r = Ractor.new do
+  obj = receive
+  { frozen: obj.frozen? }
+end
+obj = [Object.new].freeze
+r.send(obj, move: true)
+r.take[:frozen]
+}
+
 # move with yield
 assert_equal 'hello', %q{
   r = Ractor.new do
diff --git a/ractor.c b/ractor.c
index 0240d1f216..2dfd56d068 100644
--- a/ractor.c
+++ b/ractor.c
@@ -3581,6 +3581,10 @@ move_leave(VALUE obj, struct obj_traverse_replace_data *data)
         rb_replace_generic_ivar(v, obj);
     }
 
+    if (OBJ_FROZEN(obj)) {
+        OBJ_FREEZE(v);
+    }
+
     // TODO: generic_ivar
 
     ractor_moved_bang(obj);