Merge pull request #12929 from yahonda/test_merging_where_relations_add_order

Address test_merging_where_relations failure by adding order

activerecord/test/cases/relation/merging_test.rb

@@ -135,7 +135,7 @@ class MergingDifferentRelationsTest < ActiveRecord::TestCase
 
   test "merging where relations" do
     hello_by_bob = Post.where(body: "hello").joins(:author).
-      merge(Author.where(name: "Bob")).pluck("posts.id")
+      merge(Author.where(name: "Bob")).order("posts.id").pluck("posts.id")
 
     assert_equal [posts(:misc_by_bob).id,
                   posts(:other_by_bob).id], hello_by_bob