belongs_to association should always honor a present foreign key and condition interpolation should also be possible on belongs_to

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@433 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 33 insertions, 23 deletions

diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index 334cdccc3d..f4d8be8b0f 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -90,27 +90,6 @@ module ActiveRecord
         @loaded = true
       end
 
-      protected
-        def quoted_record_ids(records)
-          records.map { |record| record.quoted_id }.join(',')
-        end
-
-        def interpolate_sql_options!(options, *keys)
-          keys.each { |key| options[key] &&= interpolate_sql(options[key]) }
-        end
-
-        def interpolate_sql(sql, record = nil)
-          @owner.send(:interpolate_sql, sql, record)
-        end
-
-        def sanitize_sql(sql)
-          @association_class.send(:sanitize_sql, sql)
-        end
-
-        def extract_options_from_args!(args)
-          @owner.send(:extract_options_from_args!, args)
-        end
-
       private
         def raise_on_type_mismatch(record)
           raise ActiveRecord::AssociationTypeMismatch, "#{@association_class} expected, got #{record.class}" unless record.is_a?(@association_class)
diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index dcba207e20..424d7f818a 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -28,9 +28,30 @@ module ActiveRecord
         @loaded
       end
 
+      protected
+        def quoted_record_ids(records)
+          records.map { |record| record.quoted_id }.join(',')
+        end
+
+        def interpolate_sql_options!(options, *keys)
+          keys.each { |key| options[key] &&= interpolate_sql(options[key]) }
+        end
+
+        def interpolate_sql(sql, record = nil)
+          @owner.send(:interpolate_sql, sql, record)
+        end
+
+        def sanitize_sql(sql)
+          @association_class.send(:sanitize_sql, sql)
+        end
+
+        def extract_options_from_args!(args)
+          @owner.send(:extract_options_from_args!, args)
+        end
+
       private
         def load_target
-          unless @owner.new_record?
+          if !@owner.new_record? || foreign_key_present
             begin
               @target = find_target if not loaded?
             rescue ActiveRecord::RecordNotFound
@@ -41,6 +62,12 @@ module ActiveRecord
           @target
         end
 
+        # Can be overwritten by associations that might have the foreign key available for an association without
+        # having the object itself (and still being a new record). Currently, only belongs_to present this scenario.
+        def foreign_key_present
+          false
+        end
+
         def raise_on_type_mismatch(record)
           raise ActiveRecord::AssociationTypeMismatch, "#{@association_class} expected, got #{record.class}" unless record.is_a?(@association_class)
         end
diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb
index aa627f7495..8de48cd880 100644
--- a/activerecord/lib/active_record/associations/belongs_to_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_association.rb
@@ -45,12 +45,16 @@ module ActiveRecord
       private
         def find_target
           if @options[:conditions]
-            @association_class.find_on_conditions(@owner[@association_class_primary_key_name], @options[:conditions])
+            @association_class.find_on_conditions(@owner[@association_class_primary_key_name], interpolate_sql(@options[:conditions]))
           else
             @association_class.find(@owner[@association_class_primary_key_name])
           end
         end
 
+        def foreign_key_present
+          !@owner[@association_class_primary_key_name].nil?
+        end
+
         def target_obsolete?
           @owner[@association_class_primary_key_name] != @target.id
         end