Assign the association attributes to the associated record before the before_initialize callback of the record runs. Fixes #1842.

4 files changed, 12 insertions, 10 deletions

diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index c3aee90124..daadc8aa81 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -224,6 +224,15 @@ module ActiveRecord
         def association_class
           @reflection.klass
         end
+
+        def build_record(attributes, options)
+          reflection.build_association(attributes, options) do |record|
+            record.assign_attributes(
+              create_scope.except(*record.changed),
+              :without_protection => true
+            )
+          end
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 337a0d48f1..224e0095d9 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -423,12 +423,6 @@ module ActiveRecord
           scoped.scope_for_create.stringify_keys
         end
 
-        def build_record(attributes, options)
-          record = reflection.build_association(attributes, options)
-          record.assign_attributes(create_scope.except(*record.changed), :without_protection => true)
-          record
-        end
-
         def delete_or_destroy(records, method)
           records = records.flatten
           records.each { |record| raise_on_type_mismatch(record) }
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
index ce1f2a5543..6b010064d5 100644
--- a/activerecord/lib/active_record/associations/singular_association.rb
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -26,8 +26,7 @@ module ActiveRecord
       end
 
       def build(attributes = {}, options = {})
-        record = reflection.build_association(attributes, options)
-        record.assign_attributes(create_scope.except(*record.changed), :without_protection => true)
+        record = build_record(attributes, options)
         yield(record) if block_given?
         set_new_record(record)
         record
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 57023f5388..cfb41fd28c 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -175,8 +175,8 @@ module ActiveRecord
 
       # Returns a new, unsaved instance of the associated class. +options+ will
       # be passed to the class's constructor.
-      def build_association(*options)
-        klass.new(*options)
+      def build_association(*options, &block)
+        klass.new(*options, &block)
       end
 
       # Creates a new instance of the associated class, and immediately saves it