Remove Rails 4 compatibility fixrails-union-fix

This bug was fixed in Rails 5.1 so we don't need it
anymore.

1 files changed, 1 insertions, 7 deletions

diff --git a/app/models/concerns/from_union.rb b/app/models/concerns/from_union.rb
index 9b8595b1211..85d86a704ad 100644
--- a/app/models/concerns/from_union.rb
+++ b/app/models/concerns/from_union.rb
@@ -36,15 +36,9 @@ module FromUnion
     #            table of the current model.
     # rubocop: disable Gitlab/Union
     def from_union(members, remove_duplicates: true, alias_as: table_name)
-      union = Gitlab::SQL::Union
+      Gitlab::SQL::Union
         .new(members, remove_duplicates: remove_duplicates)
         .to_sql
-
-      # This pattern is necessary as a bug in Rails 4 can cause the use of
-      # `from("string here").includes(:foo)` to break ActiveRecord. This is
-      # fixed in https://github.com/rails/rails/pull/25374, which is released as
-      # part of Rails 5.
-      from([Arel.sql("(#{union}) #{alias_as}")])
     end
     # rubocop: enable Gitlab/Union
   end