Improved strategy for updating a belongs_to association when the foreign key changes. Rather than resetting each affected association when the foreign key changes, we should lazily check for 'staleness' (where fk does not match target id) when the association is accessed.

2 files changed, 5 insertions, 2 deletions

diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index ffcc7a081a..7d9b1104cd 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -298,7 +298,7 @@ class TestNestedAttributesOnAHasOneAssociation < ActiveRecord::TestCase
 
   def test_should_create_new_model_when_nothing_is_there_and_update_only_is_true
     @ship.delete
-    
+
     @pirate.reload.update_attributes(:update_only_ship_attributes => { :name => 'Mayflower' })
 
     assert_not_nil @pirate.ship
@@ -411,6 +411,7 @@ class TestNestedAttributesOnABelongsToAssociation < ActiveRecord::TestCase
 
   def test_should_modify_an_existing_record_if_there_is_a_matching_composite_id
     @pirate.stubs(:id).returns('ABC1X')
+    @ship.stubs(:pirate_id).returns(@pirate.id) # prevents pirate from being reloaded due to non-matching foreign key
     @ship.pirate_attributes = { :id => @pirate.id, :catchphrase => 'Arr' }
 
     assert_equal 'Arr', @ship.pirate.catchphrase
@@ -451,7 +452,7 @@ class TestNestedAttributesOnABelongsToAssociation < ActiveRecord::TestCase
 
   def test_should_not_destroy_the_associated_model_until_the_parent_is_saved
     pirate = @ship.pirate
-    
+
     @ship.attributes = { :pirate_attributes => { :id => pirate.id, '_destroy' => true } }
     assert_nothing_raised(ActiveRecord::RecordNotFound) { Pirate.find(pirate.id) }
     @ship.save
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index 1e205714a7..901c12b26c 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -7,6 +7,7 @@ require 'models/subscriber'
 require 'models/ship'
 require 'models/pirate'
 require 'models/price_estimate'
+require 'models/tagging'
 
 class ReflectionTest < ActiveRecord::TestCase
   include ActiveRecord::Reflection
@@ -194,6 +195,7 @@ class ReflectionTest < ActiveRecord::TestCase
   def test_association_primary_key
     assert_equal "id", Author.reflect_on_association(:posts).association_primary_key.to_s
     assert_equal "name", Author.reflect_on_association(:essay).association_primary_key.to_s
+    assert_equal "id", Tagging.reflect_on_association(:taggable).association_primary_key.to_s
   end
 
   def test_active_record_primary_key