Update counter cache when pushing into association

This commit fixes a regression bug in which counter_cache columns
were not being updated correctly when newly created records were
being pushed into an assocation. EG:

    # this was fine
    @post.comment.create!

    # this was fine
    @comment = Comment.first
    @post.comments << @comment

    # this would not update counters
    @post.comments << Comment.create!

1 files changed, 4 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb
index 3ba6a71366..092230b2f7 100644
--- a/activerecord/lib/active_record/associations/builder/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -25,9 +25,10 @@ module ActiveRecord::Associations::Builder
 
       mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
         def belongs_to_counter_cache_after_create_for_#{name}
-          record = #{name}
-          record.class.increment_counter(:#{cache_column}, record.id) unless record.nil?
-          @_after_create_counter_called = true
+          if record = #{name}
+            record.class.increment_counter(:#{cache_column}, record.id)
+            @_after_create_counter_called = true
+          end
         end
 
         def belongs_to_counter_cache_before_destroy_for_#{name}