Fix that Dates couldn't be subtracted from Dates after [5940].

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5954 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 12 insertions, 2 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index f1e40389e9..7d42bf9e5c 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Fix that Dates couldn't be subtracted from Dates after [5940].  [Sam Stephenson]
+
 * Add Object#acts_like? and Time#acts_like_time? and Date#acts_like_date? to facilitate duck-typing. [Jamis Buck]
 
 * Make 1.months and friends accurate by introducing a Duration class.  #6835 [eventualbuddha]
diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index f81cd9187e..b104e5271a 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -23,7 +23,11 @@ module ActiveSupport #:nodoc:
           end
           
           def minus_with_duration(other) #:nodoc:
-            self.plus_with_duration(-other)
+            if ActiveSupport::Duration === other
+              plus_with_duration(-other)
+            else
+              minus_without_duration(other)
+            end
           end
           
           # Provides precise Date calculations for years, months, and days.  The +options+ parameter takes a hash with 
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 78fc999052..22950d8710 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -10,4 +10,8 @@ class DurationTest < Test::Unit::TestCase
     assert_equal '7 days',                          1.week.inspect
     assert_equal '14 days',                         1.fortnight.inspect
   end
-end
\ No newline at end of file
+  
+  def test_minus_with_duration_does_not_break_subtraction_of_date_from_date
+    assert_nothing_raised { Date.today - Date.today }
+  end
+end