Merge pull request #8800 from acapilleri/primary_key

refactor reset_primary_key and change !blank? to present? in get_primary...

activerecord/lib/active_record/attribute_methods/primary_key.rb

@@ -76,7 +76,7 @@ def reset_primary_key #:nodoc:
         end
 
         def get_primary_key(base_name) #:nodoc:
-          return 'id' unless base_name && !base_name.blank?
+          return 'id' if base_name.blank?
 
           case primary_key_prefix_type
           when :table_name