Fix #columsn_for_distinct of MySQL and PostgreSQL

Prevent `ActiveRecord::FinderMethods#limited_ids_for` from using correct primary
key values even if `ORDER BY` columns include other table's primary key.

Fixes #28364.

activerecord/CHANGELOG.md

@@ -23,5 +23,13 @@
 
     *DHH*
 
+*   Fix `#columsn_for_distinct` of MySQL and PostgreSQL to make
+    `ActiveRecord::FinderMethods#limited_ids_for` use correct primary key values
+    even if `ORDER BY` columns include other table's primary key.
+
+    Fixes #28364.
+
+    *Takumi Kagiyama*
+
 
 Please check [5-2-stable](https://github.com/rails/rails/blob/5-2-stable/activerecord/CHANGELOG.md) for previous changes.

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -513,7 +513,7 @@ def columns_for_distinct(columns, orders) # :nodoc:
           s.gsub(/\s+(?:ASC|DESC)\b/i, "")
         }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" }
 
-        [super, *order_columns].join(", ")
+        (order_columns << super).join(", ")
       end
 
       def strict_mode?

activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb

@@ -583,7 +583,7 @@ def columns_for_distinct(columns, orders) #:nodoc:
                .gsub(/\s+NULLS\s+(?:FIRST|LAST)\b/i, "")
             }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" }
 
-          [super, *order_columns].join(", ")
+          (order_columns << super).join(", ")
         end
 
         def update_table_definition(table_name, base) # :nodoc:

activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb

@@ -25,25 +25,25 @@ def test_columns_for_distinct_zero_orders
   end
 
   def test_columns_for_distinct_one_order
-    assert_equal "posts.id, posts.created_at AS alias_0",
+    assert_equal "posts.created_at AS alias_0, posts.id",
       @conn.columns_for_distinct("posts.id", ["posts.created_at desc"])
   end
 
   def test_columns_for_distinct_few_orders
-    assert_equal "posts.id, posts.created_at AS alias_0, posts.position AS alias_1",
+    assert_equal "posts.created_at AS alias_0, posts.position AS alias_1, posts.id",
       @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "posts.position asc"])
   end
 
   def test_columns_for_distinct_with_case
     assert_equal(
-      "posts.id, CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0",
+      "CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0, posts.id",
       @conn.columns_for_distinct("posts.id",
         ["CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END"])
     )
   end
 
   def test_columns_for_distinct_blank_not_nil_orders
-    assert_equal "posts.id, posts.created_at AS alias_0",
+    assert_equal "posts.created_at AS alias_0, posts.id",
       @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "", "   "])
   end
 
@@ -52,7 +52,7 @@ def test_columns_for_distinct_with_arel_order
     def order.to_sql
       "posts.created_at desc"
     end
-    assert_equal "posts.id, posts.created_at AS alias_0",
+    assert_equal "posts.created_at AS alias_0, posts.id",
       @conn.columns_for_distinct("posts.id", [order])
   end
 

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -263,25 +263,25 @@ def test_columns_for_distinct_zero_orders
       end
 
       def test_columns_for_distinct_one_order
-        assert_equal "posts.id, posts.created_at AS alias_0",
+        assert_equal "posts.created_at AS alias_0, posts.id",
           @connection.columns_for_distinct("posts.id", ["posts.created_at desc"])
       end
 
       def test_columns_for_distinct_few_orders
-        assert_equal "posts.id, posts.created_at AS alias_0, posts.position AS alias_1",
+        assert_equal "posts.created_at AS alias_0, posts.position AS alias_1, posts.id",
           @connection.columns_for_distinct("posts.id", ["posts.created_at desc", "posts.position asc"])
       end
 
       def test_columns_for_distinct_with_case
         assert_equal(
-          "posts.id, CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0",
+          "CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0, posts.id",
           @connection.columns_for_distinct("posts.id",
             ["CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END"])
         )
       end
 
       def test_columns_for_distinct_blank_not_nil_orders
-        assert_equal "posts.id, posts.created_at AS alias_0",
+        assert_equal "posts.created_at AS alias_0, posts.id",
           @connection.columns_for_distinct("posts.id", ["posts.created_at desc", "", "   "])
       end
 
@@ -290,23 +290,23 @@ def test_columns_for_distinct_with_arel_order
         def order.to_sql
           "posts.created_at desc"
         end
-        assert_equal "posts.id, posts.created_at AS alias_0",
+        assert_equal "posts.created_at AS alias_0, posts.id",
           @connection.columns_for_distinct("posts.id", [order])
       end
 
       def test_columns_for_distinct_with_nulls
-        assert_equal "posts.title, posts.updater_id AS alias_0", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls first"])
-        assert_equal "posts.title, posts.updater_id AS alias_0", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls last"])
+        assert_equal "posts.updater_id AS alias_0, posts.title", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls first"])
+        assert_equal "posts.updater_id AS alias_0, posts.title", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls last"])
       end
 
       def test_columns_for_distinct_without_order_specifiers
-        assert_equal "posts.title, posts.updater_id AS alias_0",
+        assert_equal "posts.updater_id AS alias_0, posts.title",
           @connection.columns_for_distinct("posts.title", ["posts.updater_id"])
 
-        assert_equal "posts.title, posts.updater_id AS alias_0",
+        assert_equal "posts.updater_id AS alias_0, posts.title",
           @connection.columns_for_distinct("posts.title", ["posts.updater_id nulls last"])
 
-        assert_equal "posts.title, posts.updater_id AS alias_0",
+        assert_equal "posts.updater_id AS alias_0, posts.title",
           @connection.columns_for_distinct("posts.title", ["posts.updater_id nulls first"])
       end
 

activerecord/test/cases/finder_test.rb

@@ -1189,6 +1189,11 @@ def test_find_with_order_on_included_associations_with_construct_finder_sql_for_
       order("author_addresses_authors.id DESC").limit(3).to_a.size
   end
 
+  def test_find_with_eager_loading_collection_and_ordering_by_collection_primary_key
+    assert_equal Post.first, Post.eager_load(comments: :ratings).
+      order("posts.id, ratings.id, comments.id").first
+  end
+
   def test_find_with_nil_inside_set_passed_for_one_attribute
     client_of = Company.
       where(client_of: [2, 1, nil],