Merge branch 'master' of git@github.com:rails/rails

4 files changed, 43 insertions, 10 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 10ecd068d3..934beb7d39 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -963,6 +963,8 @@ module ActiveRecord
       #   of the association with an "_id" suffix. So a class that defines a <tt>belongs_to :person</tt> association will use
       #   "person_id" as the default <tt>:foreign_key</tt>. Similarly, <tt>belongs_to :favorite_person, :class_name => "Person"</tt>
       #   will use a foreign key of "favorite_person_id".
+      # [:primary_key]
+      #   Specify the method that returns the primary key of associated object used for the association. By default this is id.
       # [:dependent]
       #   If set to <tt>:destroy</tt>, the associated object is destroyed when this object is. If set to
       #   <tt>:delete</tt>, the associated object is deleted *without* calling its destroy method. This option should not be specified when
@@ -993,6 +995,7 @@ module ActiveRecord
       #
       # Option examples:
       #   belongs_to :firm, :foreign_key => "client_of"
+      #   belongs_to :person, :primary_key => "name", :foreign_key => "person_name"
       #   belongs_to :author, :class_name => "Person", :foreign_key => "author_id"
       #   belongs_to :valid_coupon, :class_name => "Coupon", :foreign_key => "coupon_id",
       #              :conditions => 'discounts > #{payments_count}'
@@ -1273,9 +1276,16 @@ module ActiveRecord
             if send(reflection.name).loaded? || reflection.options[:finder_sql]
               send(reflection.name).map(&:id)
             else
-              send(reflection.name).all(:select => "#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").map(&:id)
+              if reflection.through_reflection && reflection.source_reflection.belongs_to?
+                through = reflection.through_reflection
+                primary_key = reflection.source_reflection.primary_key_name
+                send(through.name).all(:select => "DISTINCT #{through.quoted_table_name}.#{primary_key}").map!(&:"#{primary_key}")
+              else
+                send(reflection.name).all(:select => "#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").map!(&:id)
+              end
             end
           end
+
         end
 
         def collection_accessor_methods(reflection, association_proxy_class, writer = true)
@@ -1321,14 +1331,14 @@ module ActiveRecord
           method_name = "belongs_to_counter_cache_after_create_for_#{reflection.name}".to_sym
           define_method(method_name) do
             association = send(reflection.name)
-            association.class.increment_counter(cache_column, send(reflection.primary_key_name)) unless association.nil?
+            association.class.increment_counter(cache_column, association.id) unless association.nil?
           end
           after_create(method_name)
 
           method_name = "belongs_to_counter_cache_before_destroy_for_#{reflection.name}".to_sym
           define_method(method_name) do
             association = send(reflection.name)
-            association.class.decrement_counter(cache_column, send(reflection.primary_key_name)) unless association.nil?
+            association.class.decrement_counter(cache_column, association.id) unless association.nil?
           end
           before_destroy(method_name)
 
@@ -1520,7 +1530,7 @@ module ActiveRecord
 
         mattr_accessor :valid_keys_for_belongs_to_association
         @@valid_keys_for_belongs_to_association = [
-          :class_name, :foreign_key, :foreign_type, :remote, :select, :conditions,
+          :class_name, :primary_key, :foreign_key, :foreign_type, :remote, :select, :conditions,
           :include, :dependent, :counter_cache, :extend, :polymorphic, :readonly,
           :validate, :touch, :inverse_of
         ]
diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb
index c88575048a..628033c87a 100644
--- a/activerecord/lib/active_record/associations/belongs_to_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_association.rb
@@ -14,7 +14,7 @@ module ActiveRecord
 
         if record.nil?
           if counter_cache_name && !@owner.new_record?
-            @reflection.klass.decrement_counter(counter_cache_name, @owner[@reflection.primary_key_name]) if @owner[@reflection.primary_key_name]
+            @reflection.klass.decrement_counter(counter_cache_name, previous_record_id) if @owner[@reflection.primary_key_name]
           end
 
           @target = @owner[@reflection.primary_key_name] = nil
@@ -27,7 +27,7 @@ module ActiveRecord
           end
 
           @target = (AssociationProxy === record ? record.target : record)
-          @owner[@reflection.primary_key_name] = record.id unless record.new_record?
+          @owner[@reflection.primary_key_name] = record_id(record) unless record.new_record?
           @updated = true
         end
 
@@ -43,13 +43,18 @@ module ActiveRecord
       
       private
         def find_target
-          the_target = @reflection.klass.find(
+          find_method = if @reflection.options[:primary_key]
+                          "find_by_#{@reflection.options[:primary_key]}"
+                        else
+                          "find"
+                        end
+          the_target = @reflection.klass.send(find_method,
             @owner[@reflection.primary_key_name],
             :select     => @reflection.options[:select],
             :conditions => conditions,
             :include    => @reflection.options[:include],
             :readonly   => @reflection.options[:readonly]
-          )
+          ) if @owner[@reflection.primary_key_name]
           set_inverse_instance(the_target, @owner)
           the_target
         end
@@ -63,6 +68,19 @@ module ActiveRecord
         def we_can_set_the_inverse_on_this?(record)
           @reflection.has_inverse? && @reflection.inverse_of.macro == :has_one
         end
+
+        def record_id(record)
+          record.send(@reflection.options[:primary_key] || :id)
+        end
+
+        def previous_record_id
+          @previous_record_id ||= if @reflection.options[:primary_key]
+                                    previous_record = @owner.send(@reflection.name)
+                                    previous_record.nil? ? nil : previous_record.id
+                                  else
+                                    @owner[@reflection.primary_key_name]
+                                  end
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
index d8146daa54..67e18d692d 100644
--- a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
@@ -7,7 +7,7 @@ module ActiveRecord
         else
           @target = (AssociationProxy === record ? record.target : record)
 
-          @owner[@reflection.primary_key_name] = record.id
+          @owner[@reflection.primary_key_name] = record_id(record)
           @owner[@reflection.options[:foreign_type]] = record.class.base_class.name.to_s
 
           @updated = true
@@ -41,6 +41,10 @@ module ActiveRecord
           !@owner[@reflection.primary_key_name].nil?
         end
 
+        def record_id(record)
+          record.send(@reflection.options[:primary_key] || :id)
+        end
+
         def association_class
           @owner[@reflection.options[:foreign_type]] ? @owner[@reflection.options[:foreign_type]].constantize : nil
         end
diff --git a/activerecord/lib/active_record/autosave_association.rb b/activerecord/lib/active_record/autosave_association.rb
index a540570f42..c1bc8423a9 100644
--- a/activerecord/lib/active_record/autosave_association.rb
+++ b/activerecord/lib/active_record/autosave_association.rb
@@ -339,7 +339,8 @@ module ActiveRecord
           association.save(!autosave) if association.new_record? || autosave
 
           if association.updated?
-            self[reflection.primary_key_name] = association.id
+            association_id = association.send(reflection.options[:primary_key] || :id)
+            self[reflection.primary_key_name] = association_id
             # TODO: Removing this code doesn't seem to matter…
             if reflection.options[:polymorphic]
               self[reflection.options[:foreign_type]] = association.class.base_class.name.to_s