Move specs to core/kernel/clone_spec

core/kernel/clone_spec.rb

@@ -1,6 +1,7 @@
 require_relative '../../spec_helper'
 require_relative 'fixtures/classes'
 require_relative 'shared/dup_clone'
+require 'set'
 
 describe "Kernel#clone" do
   it_behaves_like :kernel_dup_clone, :clone
@@ -125,4 +126,26 @@ def bar
       o.tainted?.should be_true
     end
   end
+
+  ruby_version_is ''...'3.0' do
+    it "raises FrozenError when trying to add items in the new Set" do
+      set1 = Set[1, 2]
+      set1.freeze
+      set2 = set1.clone(freeze: false)
+
+      # versions previous to 3.0 used to freeze the internal hash for the new object even when
+      # using freeze: false
+      -> { set2.add 3 }.should raise_error(FrozenError)
+    end
+  end
+
+  ruby_version_is '3.0' do
+    it 'does not raise FrozenError when trying to add items in the new Set' do
+      set1 = Set[1, 2]
+      set1.freeze
+      set2 = set1.clone(freeze: false)
+
+      -> { set2.add 3 }.should_not raise_error(FrozenError)
+    end
+  end
 end