validates method should not change options argument

2 files changed, 7 insertions, 1 deletions

diff --git a/activemodel/lib/active_model/validations/validates.rb b/activemodel/lib/active_model/validations/validates.rb
index 8e09f6ac35..0e6b349e94 100644
--- a/activemodel/lib/active_model/validations/validates.rb
+++ b/activemodel/lib/active_model/validations/validates.rb
@@ -80,7 +80,7 @@ module ActiveModel
       #   validates :password, :presence => true, :confirmation => true, :if => :password_required?
       #
       def validates(*attributes)
-        defaults = attributes.extract_options!
+        defaults = attributes.extract_options!.dup
         validations = defaults.slice!(*_validates_default_keys)
 
         raise ArgumentError, "You need to supply at least one attribute" if attributes.empty?
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index 2f4376bd41..ed4d8fcdca 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -330,4 +330,10 @@ class ValidationsTest < ActiveModel::TestCase
       Topic.new.valid?
     end
   end
+
+  def test_does_not_modify_options_argument
+    options = {:presence => true}
+    Topic.validates :title, options
+    assert_equal({:presence => true}, options)
+  end
 end