Don't use select() values from the join model of a through association. Fixes #508.

5 files changed, 23 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
index e436fef46d..53c5c3cedf 100644
--- a/activerecord/lib/active_record/associations/through_association.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -14,9 +14,10 @@ module ActiveRecord
         def target_scope
           scope = super
           chain[1..-1].each do |reflection|
-            # Discard the create with value, as we don't want that the affect the objects we
-            # create on the association
-            scope = scope.merge(reflection.klass.scoped.create_with(nil))
+            scope = scope.merge(
+              reflection.klass.scoped.with_default_scope.
+                except(:select, :create_with)
+            )
           end
           scope
         end
diff --git a/activerecord/test/cases/associations/has_one_through_associations_test.rb b/activerecord/test/cases/associations/has_one_through_associations_test.rb
index 968025ade8..2503349c08 100644
--- a/activerecord/test/cases/associations/has_one_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_through_associations_test.rb
@@ -310,4 +310,8 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal dashboard, minivan.dashboard
     assert_equal dashboard, minivan.speedometer.dashboard
   end
+
+  def test_has_one_through_with_custom_select_on_join_model_default_scope
+    assert_equal clubs(:boring_club), members(:groucho).selected_club
+  end
 end
diff --git a/activerecord/test/fixtures/memberships.yml b/activerecord/test/fixtures/memberships.yml
index 60eb641054..a5d52bd438 100644
--- a/activerecord/test/fixtures/memberships.yml
+++ b/activerecord/test/fixtures/memberships.yml
@@ -25,3 +25,10 @@ blarpy_winkup_crazy_club:
   member_id: 3
   favourite: false
   type: CurrentMembership
+
+selected_membership_of_boring_club:
+  joined_on: <%= 3.weeks.ago.to_s(:db) %>
+  club: boring_club
+  member_id: 1
+  favourite: false
+  type: SelectedMembership
diff --git a/activerecord/test/models/member.rb b/activerecord/test/models/member.rb
index 991e0e051f..11a0f4ff63 100644
--- a/activerecord/test/models/member.rb
+++ b/activerecord/test/models/member.rb
@@ -1,8 +1,10 @@
 class Member < ActiveRecord::Base
   has_one :current_membership
+  has_one :selected_membership
   has_one :membership
   has_many :fellow_members, :through => :club, :source => :members
   has_one :club, :through => :current_membership
+  has_one :selected_club, :through => :selected_membership, :source => :club
   has_one :favourite_club, :through => :membership, :conditions => ["memberships.favourite = ?", true], :source => :club
   has_one :hairy_club, :through => :membership, :conditions => {:clubs => {:name => "Moustache and Eyebrow Fancier Club"}}, :source => :club
   has_one :sponsor, :as => :sponsorable
diff --git a/activerecord/test/models/membership.rb b/activerecord/test/models/membership.rb
index 905f948c37..bcbb7e42c5 100644
--- a/activerecord/test/models/membership.rb
+++ b/activerecord/test/models/membership.rb
@@ -7,3 +7,9 @@ class CurrentMembership < Membership
   belongs_to :member
   belongs_to :club
 end
+
+class SelectedMembership < Membership
+  def self.default_scope
+    select("'1' as foo")
+  end
+end