1 files changed, 9 insertions, 2 deletions
diff --git a/lib/set.rb b/lib/set.rb
index 0ad47c842f..e244712833 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -301,8 +301,8 @@ class Set
   # ((set | enum) - (set & enum)).
   def ^(enum)
     enum.is_a?(Enumerable) or raise ArgumentError, "value must be enumerable"
-    n = dup
-    enum.each { |o| if n.include?(o) then n.delete(o) else n.add(o) end }
+    n = Set.new(enum)
+    each { |o| if n.include?(o) then n.delete(o) else n.add(o) end }
     n
   end
 
@@ -1049,6 +1049,13 @@ class TC_Set < Test::Unit::TestCase
     assert_equal(Set[2,4], ret)
   end
 
+  def test_xor
+    set = Set[1,2,3,4]
+    ret = set ^ [2,4,5,5]
+    assert_not_same(set, ret)
+    assert_equal(Set[1,3,5], ret)
+  end
+
   def test_eq
     set1 = Set[2,3,1]
     set2 = Set[1,2,3]