From e4e62fbdc63374f9475d6768a2b4c3b3747d6362 Mon Sep 17 00:00:00 2001
From: alpaca-tc <alpaca-tc@alpaca.tc>
Date: Thu, 5 Nov 2020 20:52:27 +0900
Subject: [PATCH] ActiveModel::Model can be frozen again

---
 activemodel/lib/active_model/attributes.rb | 2 +-
 activemodel/test/cases/attributes_test.rb  | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/activemodel/lib/active_model/attributes.rb b/activemodel/lib/active_model/attributes.rb
index 91441858f6..de94b1cf3b 100644
--- a/activemodel/lib/active_model/attributes.rb
+++ b/activemodel/lib/active_model/attributes.rb
@@ -115,7 +115,7 @@ module ActiveModel
     end
 
     def freeze
-      @attributes = @attributes.clone.freeze
+      @attributes = @attributes.clone.freeze unless frozen?
       super
     end
 
diff --git a/activemodel/test/cases/attributes_test.rb b/activemodel/test/cases/attributes_test.rb
index dd4922fe44..5e3ceda468 100644
--- a/activemodel/test/cases/attributes_test.rb
+++ b/activemodel/test/cases/attributes_test.rb
@@ -129,5 +129,11 @@ module ActiveModel
       assert data.frozen?
       assert_raise(FrozenError) { data.integer_field = 1 }
     end
+
+    test "attributes can be frozen again" do
+      data = ModelForAttributesTest.new
+      data.freeze
+      assert_nothing_raised { data.freeze }
+    end
   end
 end