Implement Set#clone. [Fixes GH-661]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Wed Aug  6 19:09:27 2014  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/set.rb (Set): Implement Set#clone by splitting
+	  initialize_copy into initialize_dup and initialize_clone.
+	  Submitted by yui-knk. [Fixes GH-661]
+	  https://github.com/ruby/ruby/pull/661
+
 Wed Aug  6 18:42:58 2014  Masaki Suketa <masaki.suketa@nifty.ne.jp>
 
 	* ext/win32ole/win32ole.c: separate src of WIN32OLERuntimeError

lib/set.rb

@@ -100,11 +100,18 @@ class Set
   end
   private :do_with_enum
 
-  # Copy internal hash.
-  def initialize_copy(orig)
+  # Dup internal hash.
+  def initialize_dup(orig)
+    super
     @hash = orig.instance_variable_get(:@hash).dup
   end
 
+  # Clone internal hash.
+  def initialize_clone(orig)
+    super
+    @hash = orig.instance_variable_get(:@hash).clone
+  end
+
   def freeze    # :nodoc:
     @hash.freeze
     super

test/test_set.rb

@@ -585,6 +585,28 @@ class TC_Set < Test::Unit::TestCase
     assert_equal 4, set.size
   end
 
+  def test_freeze_dup
+    set1 = Set[1,2,3]
+    set1.freeze
+    set2 = set1.dup
+
+    assert_not_predicate set2, :frozen?
+    assert_nothing_raised {
+      set2.add 4
+    }
+  end
+
+  def test_freeze_clone
+    set1 = Set[1,2,3]
+    set1.freeze
+    set2 = set1.clone
+
+    assert_predicate set2, :frozen?
+    assert_raise(RuntimeError) {
+      set2.add 5
+    }
+  end
+
   def test_inspect
     set1 = Set[1]