Fix Date#years_ago and #years_since from leap days. Closes #9864.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7863 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

 *SVN*
 
+* Fix Date#years_ago and #years_since from leap days.  #9864 [Geoff Buesing]
+
 * Refactor Time and Date#months_since and #months_ago to use #advance.  #9863 [Geoff Buesing]
 
 * Rebundle Builder 2.1.2 but prefer a newer RubyGem if available.  [Jeremy Kemper]

activesupport/lib/active_support/core_ext/date/calculations.rb

@@ -103,12 +103,12 @@ def months_since(months)
 
         # Returns a new Date/DateTime representing the time a number of specified years ago
         def years_ago(years)
-          change(:year => self.year - years)
+          advance(:years => -years)
         end
 
         # Returns a new Date/DateTime representing the time a number of specified years in the future
         def years_since(years)
-          change(:year => self.year + years)
+          advance(:years => years)
         end
 
         # Short-hand for years_ago(1)

activesupport/test/core_ext/date_ext_test.rb

@@ -94,12 +94,14 @@ def test_months_since
   def test_years_ago
     assert_equal Date.new(2004,6,5),  Date.new(2005,6,5).years_ago(1)
     assert_equal Date.new(1998,6,5), Date.new(2005,6,5).years_ago(7)
+    assert_equal Date.new(2003,2,28), Date.new(2004,2,29).years_ago(1) # 1 year ago from leap day
   end
 
   def test_years_since
     assert_equal Date.new(2006,6,5),  Date.new(2005,6,5).years_since(1)
     assert_equal Date.new(2012,6,5),  Date.new(2005,6,5).years_since(7)
     assert_equal Date.new(2182,6,5),  Date.new(2005,6,5).years_since(177)
+    assert_equal Date.new(2005,2,28), Date.new(2004,2,29).years_since(1) # 1 year since leap day
   end
 
   def test_last_year

activesupport/test/core_ext/date_time_ext_test.rb

@@ -112,12 +112,14 @@ def test_months_since
   def test_years_ago
     assert_equal DateTime.civil(2004,6,5,10),  DateTime.civil(2005,6,5,10,0,0).years_ago(1)
     assert_equal DateTime.civil(1998,6,5,10), DateTime.civil(2005,6,5,10,0,0).years_ago(7)
+    assert_equal DateTime.civil(2003,2,28,10), DateTime.civil(2004,2,29,10,0,0).years_ago(1) # 1 year ago from leap day
   end
 
   def test_years_since
     assert_equal DateTime.civil(2006,6,5,10),  DateTime.civil(2005,6,5,10,0,0).years_since(1)
     assert_equal DateTime.civil(2012,6,5,10),  DateTime.civil(2005,6,5,10,0,0).years_since(7)
     assert_equal DateTime.civil(2182,6,5,10),  DateTime.civil(2005,6,5,10,0,0).years_since(177)
+    assert_equal DateTime.civil(2005,2,28,10), DateTime.civil(2004,2,29,10,0,0).years_since(1) # 1 year since leap day
   end
 
   def test_last_year