Support obj.clone(freeze: true) for freezing clone

This freezes the clone even if the receiver is not frozen.  It
is only for consistency with freeze: false not freezing the clone
even if the receiver is frozen.

Because Object#clone is now partially implemented in Ruby and
not fully implemented in C, freeze: nil must be supported to
provide the default behavior of only freezing the clone if the
receiver is frozen.

This requires modifying delegate and set, to set freeze: nil
instead of freeze: true as the keyword parameter for
initialize_clone.  Those are the two libraries in stdlib that
override initialize_clone.

Implements [Feature #16175]

1 files changed, 12 insertions, 0 deletions

diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 55709bf3dc..3aa0a1b652 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -47,15 +47,27 @@ class TestObject < Test::Unit::TestCase
     a = Object.new
     def a.b; 2 end
 
+    c = a.clone
+    assert_equal(false, c.frozen?)
+    assert_equal(false, a.frozen?)
+    assert_equal(2, c.b)
+
+    c = a.clone(freeze: true)
+    assert_equal(true, c.frozen?)
+    assert_equal(false, a.frozen?)
+    assert_equal(2, c.b)
+
     a.freeze
     c = a.clone
     assert_equal(true, c.frozen?)
+    assert_equal(true, a.frozen?)
     assert_equal(2, c.b)
 
     assert_raise(ArgumentError) {a.clone(freeze: [])}
     d = a.clone(freeze: false)
     def d.e; 3; end
     assert_equal(false, d.frozen?)
+    assert_equal(true, a.frozen?)
     assert_equal(2, d.b)
     assert_equal(3, d.e)